CRUISE NARRATIVE (S04)

Highlights 

                        WHP Cruise Summary Information

                WOCE section designation  S04
       Expedition designation (ExpoCode)  74DI200_1

Chief Scientist(s) and their affiliation  Robert R. Dickson/MAFF
                                          Lowestoft Laboratory
                                          MINISTRY OF AGRICULTURE FISHERIES AND FOOD
                                          DIRECTORATE OF FISHERIES RESEARCH
                                          Lowestoft  Suffolk  NR330HT  UK 

                                   Dates  1993 FEB 6 - 1993 MAR 18
                                    Ship  RRS DISCOVERY
                           Ports of call  Cape Town
                                          
                      Number of stations  25

                                               40°S
         Stations' Geographic boundaries  20°E      90°E
                                               65°S

            Floats and drifters deployed  0
          Moorings deployed or recovered  16

                             Contributing Authors:
                    -----------------------------------------
                    A.J. Watson/PML        M.J. Griffiths/JRC
                    C. Day/RVS             N.D. Pearson/MAFF
                    D.S. Kirkwood/MAFF     N.P. Holliday/IOSDL
                    G.W. Hargreaves/POL    P.D. Cotton/JRC
                    I. Waddington/IOSDL    P.G. Taylor/RVS
                    J. Brown/MAFF          P.J. Mason/RVS
                    J. Robertson/UCNW      P.R. Foden/POL
                    J.W. Read/MAFF         R.B. Loyd/RVS
                    M .J. Griffiths/JRC    R.D. Frew/UEA
                    M. Krysell/U.Goteborg  S.R. Jones
                    M.D. Sparrow/UEA       T.W.N. Haine/UEA
                    M.I. Liddicoat/PML     W.J. Gould/IOSDL
                       
                                           
SCIENTIFIC PERSONNEL				SHIP'S PERSONNEL
--------------------				----------------
Dickson, R. R.		MAFF			Avery, K. 0.		Master
(Principal Scientist)
Brown, J.		MAFF			Louch, A. R.		Chief Officer
Cotton, P. D.		JRC			Boult, T. J.		2nd Officer
Day, C.	RVS					Atkinson, R. M.		3rd Officer
Foden, P. R.		POL			Stewart, D.		Radio Officer
Frew, R. D.		UEA			Macaulay, 1. 1.		Doctor
Gould, W. J.		IOSDL			Moss, S. A.		Chief Engineer.
Griffiths, M. J.	JRC			Mcdonald, B. J.		2nd Engineer
Haine, T. W. N.		UEA			Phillips, C. J.		3rd Engineer
Hargreaves, G. W.	POIL			Parker, P. G.		Electrician
Holliday, N. P.		IOSDL			Drayton, M. J.		CPO(D)
Jones, S. R.		MAFF			Vrettos, C.		SIA
Kirkwood, D. S.		MAFF			Gibson, M. S.		SlA
Krysell, M.		AMK, U. Goteborg	Buffery, D. G.		SIA
Liddicoat, M. 1.	PNIEL			Crabb, G.		SlA
Lloyd, R. B.		RVS			Cook, S. C.		SlA
Mason, P. J.		RVS			Olds, A. E.		SIB
Pearson, N. D.		MAFF			Staite, E.		SCM
Read, J. W.		MAFF			Swenson, J. J. E.	Chef
Robertson, J.		UCNW			Smith, L. V.		Mess Steward
Sparrow, M. D.		UEA			Duncan, A. S.		Steward
Taylor, R G.		RVS			Link, W. J. T.		Steward
Turner, S. M.		UEA			Healy, A.		Motorman I A
Waddington, 1.		IOSDL		
Watson, A. J.		PN11L		

SCIENTIFIC OBJECTIVES 

The main scientific objectives and activities of DISCOVERY 200 form part of a 
wider international investigation into the rates and pathways of the global 
abyssal circulation as a component of the World Ocean Circulation Experiment 
(WOCE), and are intended to coordinate with other research programmes being 
undertaken in the Southern Ocean as part of the UK WOCE effort. 

The principal objectives were as follows: 

1.	To make direct measurements of the flow of deep and bottom waters 
	passing eastwards from the Enderby Abyssal Plain to the Southern Indian Ocean 
	via deep topographic gaps to the northeast and southeast of the Kerguelen 
	Plateau. Specifically, to lay two main arrays of current meters with 10 
	moorings (42 current meters) and 2 Bottom Pressure Recorders in the main gap 
	between Crozet and Kerguelen, supplemented with a mooring in the deep cleft 
	immediately to the west of Crozet Island, and a further 5 moorings (13 c/m) in 
	the Princess Elizabeth Trough between the Kerguelen Plateau and Antarctica.

2.	To extend two of the moorings of the main Crozet-Kerguelen array up into 
	the near-surface layers to aid the subsequent SWINDEX investigation into the 
	interactions of the Agulhas and Antarctic Circumpolar Currents (DISCOVERY 
	201).

3.	To use a range of tracers including the CFCs 1 0, 11, 12,113, inorganic 
	nutrients, dissolved oxygen, and oxygen and hydrogen isotopes (indicating 
	meltwater content) to partition the deep throughflow into its constituent 
	watermasses and to identify these as to source using a widely-spaced set of 
	upstream measurements [on this cruise and using the complementary data set 
	from the Swedish Antarctic Research Program, (SWEDARP) aboard RV LANCE in the 
	Weddell Sea area].

4.	To make discrete measurements of C02 partial pressure in seawater 
	(pCO2), total seawater C02 content (TC02) and appropriate measures of 
	biological activity throughout the cruise-track as a BOFS/PRIME component of 
	the BAS Antarctic Special Topic, and as a necessary determinand of WOCE.

5.	To make measurements of biogenic dimethylsulphide (DMS) and its 
	precursor (DMSP) at regular intervals throughout the ship's track, as a 
	component programme of the BAS Antarctic Special Topic.

6.	To monitor a suite of discontinuous and continuous environmental 
	variables throughout the cruise, including bathymetry from PES, XBT, ADCP, 
	multimet, wave recorder and thermosalinograph.

7.	To use a range of satellite-derived ice and weather intelligence where 
	possible and appropriate.

All these objectives were met in full with the exception of number 4. There 
the lack of a fluorometer restricted the ancillary monitoring of biological 
activity to hourly filtered samples, and the earlier inadvertent loss of the 
WOCE TC02 standard during the Ship's passage south in 1992 reduced the 
usefulness of these measurements also, as it had for DISCOVERY 198. The 
outcome is that WOCE standards will be met on this cruise for PC02 but not 
TCO2. 


NARRATIVE (Figures 1(a)*-(c)*)

During the few days prior to sailing, our chief preoccupation was with the CFC 
gear from the University of Goteborg which had been embargoed by Customs/DTI 
at Heathrow while passing through to Cape Town under carnet. This problem was 
resolved in time to catch the late night plane on Friday 5 February so that 
this final consignment arrived aboard ship in the early afternoon of Saturday 
6 February/Day 37. (Day numbers and GMT will be used throughout the remainder 
of this Narrative.) The ship sailed from Cape Town at 1302, day 37, only a few 
hours later than planned. Heading south towards our first main working area, 
the ADCP was calibrated on a straight-line course while on bottom-track, and a 
trial of a suspect load cell on the CTD winch was conducted when the bottom 
deepened to 1500 m. The PES fish was deployed at 1840, and watches began 
thereafter. For the remainder of the cruise except during the more intensive 
periods of station and mooring work, when personnel were deployed to other 
duties, these watches maintained continuous monitoring of the suite of 
environmental parameters - bathymetry/PES, ADCP, Multimet, thermosalinograph 
and four-hourly XBT. Later during day 37 the ADCP recorded a spectacular 
Agulhas signal of about 100 cm s-1 westward. 

Fig 1(a)*.	Track chart

Day 38, which began with 30 knots on the bow and a good swell was largely 
spent in setting-up, with continued trials of the CTD winch system to check 
the effect of repairs. It was at this stage, during the setting-up and first 
trials of the PC02 and DMS analysis systems that the lack of a fluorometer was 
noticed for the first time. The hourly filtration and freezing of 
phytoplankton samples began as a substitute and was to continue throughout The 
cruise, but the lack of any continuous measure of a variable as rapidly-
changing as phytoplankton standing stock was a continuing and serious drawback 
to the interpretation of both PC02 and DMS distributions. This was compounded 
in the case of TC02 by the continuing effect of the inadvertent destruction 
through freezing and breakage of the appropriate WOCE standard during the 
vessel's passage southwards the previous year. This meant that while pCO2 
determinations were to WOCE standard, the TC02 results were not. It was at 
this stage too that the CFC system was experiencing an unacceptably high 
contamination level, but this problem was overcome and it remained clean 
throughout the cruise, although - at the levels of accuracy demanded by our 
deep water objectives - not without a considerable and continuing effort to 
keep it that way, and a few transient alarms. 

By day 39, all systems were sufficiently up and running to justify a full-
depth CTD station, and this was worked to 4818 in the Agulhas Basin, combined 
(as was to be our usual practice) with the deep wire-test of two acoustic 
releases mounted on the outer ring of the Multisampler rosette. Although both 
releases were subsequently discovered to have fired when examined aboard ship, 
the loss of the Waterfall system (which had crashed its hard disk)and the 
noisy acoustic conditions with 30 knots and a large swell made the actual wire 
test somewhat ambiguous. The chemistry posed few problems on this first run, 
although we found no way to operate the UCNW endpoint detection system for 
oxygen and had to rely on more traditional methods. This situation persisted 
throughout the cruise but the comparison of the bottle oxygens with those from 
the CTD 02 sensor proved no worse than on the previous cruise, DISCOVERY 199. 

The remainder of our southward passage to our first main working area passed 
uneventfully, although the early appearance of our first substantial bergy 
bits of ice on day 41 at 47.5°S accelerated the demand for the fullest 
possible range of ice intelligence by the Master; from then on since we were 
rarely free from the presence of ice, the ship's speed was reduced to 5-6 
knots during the hours of darkness to minimise the risks of collision with sea 
ice too small to be detected on radar. This practice continued until the 
vessel passed northwards through the Antarctic Convergence once again some 21 
days later, and though it might have affected progress around our long sea-
track, in practice it had no noticeable effect since nights were short and 
daytime sea-states were such as to allow full speed. 

Some replanning of an optimum cruise track for following the Weddell Sea 
outflow eastwards towards Kerguelen had taken place during the steam south. It 
was thought that the original plan of working a zonal line of widely-spaced 
stations would suffer from ambiguities of not knowing where they were located 
in relation to the expected zonal tongue of tracer. Accordingly it was decided 
that the tongue and its eastward change in characteristics would be better 
defined by adding a further meridional section across the tongue to supplement 
the existing or prospective SWEDARP, A-23 and AJAX freon sections further west 
and the 1-6, ANTARES, and our own freon sections further east. 

With some regard to the need to reduce our track-length where practicable, a 
900 mile 7-station section was planned running southeastwards from the 
Southwest Indian Ridge crest at 52°S 18°E, to the Gunnerus Ridge which carries 
the Antarctic Continental Margin northwards clear of the ice-edge at 64°S 32°E 
approximately. This section was worked without incident and in steadily 
improving weather from 1107, day 42 to 0914, day 48. Pairs of acoustic 
releases were wire tested on each lowering, and during the lengthy period of 
sequential sampling from the 24-bottle rosette before the ship moved off-
station, the opportunity was taken to stretch mooring cable over the stem 
using the double barrel capstan winch in preparation for mooring-work to come. 

This protracted period of CTD work highlighted the recurrence of an old 
problem of misfiring by the Multisampler, encountered on earlier cruises, and 
which - even with a great deal of painstaking work by RVS staff - we were 
never to be free from for more than three or four stations on this cruise. 
While misfiring was light to moderate, we were well able to assign the true 
bottle firing sequences and depths by reference to silicate levels and bottle: 
CTD salinity differences. However the heavy misfiring that occurred towards 
the end of this first CTD section began to cost us valuable vertical 
resolution as an unacceptable number of double-firings took place, and on the 
final station, continuous misfiring from mid-depths upward forced a second 
cast. 

A second potential problem that proved more tractable was the fact that on the 
abyssal plain stations deeper than 5000 m, the wire loadings from the wire 
weight and from our draggy rosette were nearing or exceeding the preferred RVS 
working limit of 2.25 t. Calm weather and the removal of unnecessary 
instruments (releases) from the rosette solved the problem for the few 
remaining very deep stations. 

Thereafter, from leaving the Gunnerus Ridge at 0914, day 48 until arrival at 
our second main working area in the Princess Elizabeth Trough (PET) at 0800, 
day 54, advantage was taken of the long steam to strip down and repair the 
multisampler, recalibrate the ADCP on a zig-zag run off Cape Ann, complete 
analysis and fault-finding on the freon system, and to begin a series of 
informal seminars for all ship's staff. In addition, the vessel diverted 
close-in to the Antarctic Slope to re-work a French freon station that had 
found enhanced near-bottom freons 5 years earlier, and essentially-similar 
conditions were found. 

To aid our eastward navigation around the ice-edge and to prepare us for 
conditions in the Princess Elizabeth Trough, every possible form of ice 
intelligence was brought to bear, including direct imagery, analyses of ice-
edge position from NOAA and the Met. Office, the ice edge from satellite 
altimetry by the Mullard Space Science Lab and some preliminary radio 
interchanges with the nearby Australian bases at Mawson and Davis. In the 
event, ice conditions proved light and were no problem to our PET operations. 

From arrival 0800, day 54 to departure at 0415, day 56, DISCOVERY was able to 
work her full planned programme of 8 full-depth CTD casts and 5 current meter 
moorings across the Trough in moderate-to-placid weather conditions, including 
a double dip at the southernmost point to obtain a Cadmium profile for Dr. 
Frew. At 2000, day 56, watches were resumed for the steam north along the 
Kerguelen Plateau to our third and final working area in the Crozet-Kerguelen 
Gap. The resumption of the Multisampler's misfire problems on the final Trough 
station because of water in the wafer switch, and some brief contamination 
worries in the freon system brought the same needs for repair work en route. 
Wind and swell conditions worsened more or less continuously during this 
north-bound leg bringing extended periods of steaming at reduced speed, and 
station work was restricted to the collection of a full 24-bottle rosette 
sample from the deep freon minimum layer (1000 m) west of Heard Is. to check 
the multisampler for possible freon contamination (negative). 

On arrival west of Kerguelen, the vessel immediately started into the heavy 
work schedule of her third main working area. From 0900, day 63 until 1540, 
day 69 and despite recurrent and persistent rough weather conditions, the ship 
was able to complete her full planned programme of 10 Current meter moorings 
in the Crozet-Kerguelen Gap, including two full-depth rigs during temporary 
lulls on days 65 and 68 and after bathymetric survey had confirmed suitable 
topography in each case; the two POL Bottom Pressure Recorders had been 
precisely located on the 3600 m contour at either end of the array; and a 
total of 9 full-depth and fully-sampled CTD/freon stations had been worked 
between the moorings. During this period, the vessel was forced to abandon 
work and dodge on only one occasion from noon day 66 to noon on the following 
day while windspeeds gusted to 60-70 knots, and on only one other occasion 
(during mooring 93-13) did working conditions become marginal. They were 
almost continually difficult however and the fact that we fulfilled our entire 
work schedule on time in this key area is due in no small measure to the skill 
and willingness of the Ship's officers and crew in taking each realistic 
chance that offered. 

Only one of the 10 moorings (93-08) failed to respond to interrogation after 
deployment suggesting a possible problem next year, but this may merely 
reflect the poor acoustic conditions prevailing at that time. 

From 1540, day 69 with the work east of Crozet completed and in the first calm 
and sunny conditions for several days, DISCOVERY continued west to the 
detached mooring site in the deep cleft west of Crozet. There, the final 
(eighteenth) mooring was set by 1345, day 70, followed by its corresponding 
CTD station by 1715. During this station, most components of the CTD system 
began to show signs of fatigue: the gantry initially refused to go through its 
usual deployment evolutions, an altimeter connector problem caused data 
dropout, the multisampler started to register multiple misfires (although 
without actually misfiring), and a hydraulic hammering began to be obvious in 
the pipes of the CTD winch. 

Accordingly, with her full work programme essentially complete, DISCOVERY set 
sail for Cape Town, and watchkeeping with XBT and environmental monitoring as 
normal was resumed from 2000. Thereafter, with the exception of a shallow CTD 
dip to 500 m on day 73 to check on repairs to the system and to provide a 
third near-surface Cadmium profile for Dr. Frew, the work programme was run 
down, and after an afterdeck barbeque, slide show and RPC on the afternoon of 
day 75, DISCOVERY continued uneventfully to Cape Town, docking at 1115, day 
77. 

The almost complete fulfillment of such a complex set of objectives over a 
cruise track some 7673 miles long and often in trying circumstances says much 
for the capabilities of the renewed vessel; the high morale of the scientific 
staff throughout the cruise was as much the result of the astonishing quality 
of the catering as a reflection of their own undoubted achievements; and 
finally, it is a pleasure to acknowledge the considerable part played by the 
entire ship's complement in meeting the demands of our work programme with 
skill and flexibility. Together, these elements made for a memorable and 
enjoyable cruise. 

RRD, PSO
RRS DISCOVERY 200
March 1993

--------------------------------------------------------------------------------

INDIVIDUAL PROJECT REPORTS
(P.G. Taylor/RVS, W.J. Gould/IOSDL, J. Brown/MAFF)

Figure 1(b)*.	Chart showing CTD station positions

CTD operations

The CTD/multisampler package consisted of the IOSDL NBIS Mk 111B with Beckman 
oxygen sensor. The CTD lay horizontally with the axis of the conductivity 
sensor vertical and alongside the SeaTech I m folded-path transmissometer. 
These were located beneath the General Oceanics 24 x 10 1 multisampler and all 
enclosed within a weighted protective frame. The package was also fitted with 
a Simrad 200 kHz altimeter which measured height above bottom when within the 
lockout range of 204.8 m. On early stations a 10 kHz bottom finding pinger was 
attached but this was removed after the first station as its signals 
interfered with the interpretation of the tests of acoustic releases which 
were carried out by attaching the release units to the outside of the CTD 
frame. 

The CTD package was prepared initially by cleaning the transmissometer glass 
faces and measuring the voltage output. However by the middle of the cruise 
persistent problems were encountered with noisy transmissometer data. Changing 
the cable harness did not cure the problem which was traced to corrosion of 
one of the connector pins on the transmissometer. In view of this, from 
station 12373 onwards the transmissometer faces were cleaned but the air 
calibration voltage not measured. The deck values of pressure and temperature 
were noted before deployment. 

Many stations were worked in conditions of large swell and, to avoid having to 
keep the CTD package near the sea surface at the start of each station, data 
logging was started with the CTD on deck and lowering was continuous once the 
CTD had entered the water. Lowering rates were low (30 m/min or less) for the 
top 1000 m or so of each cast, depending on sea state, and increased to 50-60 
m/min at deeper levels. This ensured that there was little chance of damaging 
the wire and indeed the only requirement to re-terminate the wire during the 
cruise was when it was damaged by welding work on deck. 

The CTD was lowered typically to within 20 m of the sea bed, the down cast 
terminated and the bottles fired on the up cast. Hauling rates ranged from 50-
70 m/min but were slower to avoid high tensions on stations to 5000 m or more 
early in the cruise. There were, as on almost all cruises, persistent problems 
with the multisampler reliability. 

On recovery the deck values of CTD pressure and temperature were again noted, 
bottles checked for leaking taps and end caps and the digital pressure and 
temperature meters on bottles 1,4,8 and 12 recorded. 

Sampling was in the following sequence

CFCs, Oxygen, Nutrients, Salinity, Oxygen/hydrogen isotope ratios. 

Information on individual stations is given in Table 1. 

Apart from the transmissometer problems mentioned above, the CTD ran 
faultlessly until the last full depth station (12385). Here pressure spikes 
and data dropout started and persisted throughout the cast despite a change to 
the duplicate CTD power supply. The fault was later identified as being in a 
leaking connector on the altimeter. This and an accumulation of dirt on the 
winch slip rings was causing a drop in cable voltage and hence affecting other 
data channels. The fault was rectified prior to the final station. 


Rosette multisamplers
(P.G. Taylor/RVS)

A modified General Oceanics 24 bottle rosette multisampler, fitted with 10 1 
Niskin bottles was used with the CTD package. The modification incorporated a 
set of EG&G electronics modules, which permitted bottle firing without loss of 
CTD data. Whilst the EG&G units worked fine, the General Oceanics 
electromechanical pylon assemblies (s/n I and 2) persistently gave trouble. 
The problems experienced on DISCOVERY 199 recurred, s/n 1 double fired and 
occasionally jammed whilst s/n 2 was prone to leakage. S/n I was found to have 
a worn ramp shaft assembly and loose motor housing; s/n 2 had a pitted ramp 
shaft o-ring groove and a corroded motor housing. S/n 2 was serviced and 
performed adequately for most of the cruise. During the last CTD section 
another slight leakage caused corruption of the confirmation signals but did 
not affect bottle firing. Replacement spare parts were requested for DISCOVERY 
201. 


CTD data processing (Figure 2*)
(M .J. Griffiths/JRC, W.J. Gould/IOSDL)

Figure 2*.	Cruise 200 data processing path

Processing of CTD data was in two parts; one for the continuous, I hertz data, 
the second for the bottle sample data. The two parts met for the purpose of 
calibrating the continuous salinity and oxygen data against the bottle 
samples. 

Continuous CTD data were read from the level C, and converted to PSTAR. The 
raw data were calibrated using established PEXEC routines which, having been 
documented in previous cruise reports, are not described in great detail here. 
Readers are referred to the CTD data report for DISCOVERY 189 for more detail. 
In brief, the following processing was carried out on the data. Pressure data 
were corrected with an exponential decay to offset the response of the cell to 
changes in temperature with time. Additionally, upcast pressures were adjusted 
to minimise the effects of hysteresis. Because the temperature sensor responds 
more slowly than the conductivity sensor, temperature data were accelerated 
(approx. 0.2 seconds) to match with the conductivity measurements. Temporary 
calibrations were applied to the salinity and oxygen data, and were updated 
after comparison with the bottle data. The I hertz data from the downcast were 
median despiked, with gaps filled using linear interpolation, then averaged 
into 2 dbar intervals. 

Bottle firing times and codes were logged on the RVS level C. These data were 
read to PSTAR and merged with winch data (cable out), and 10 second averaged, 
continuous data from the CTD upcast. Since oxygen data from the upcast is 
unreliable, (due to the inconsistent flow past the sensor), oxygen data from 
the downcast were used, matching on pressure with the upcast. The resulting 
firing file contained continuous CTD data at the times when bottles were 
supposedly fired, (which in some cases was more than he number of bottles). By 
comparing these data with the sampled data, the true sequence of firing depths 
was produced, and the firing file was reordered accordingly to contain 24 
values. 

Meanwhile, sample data from the bottles (including reversing thermometer and 
pressure sensors) were collected in separate Excel spreadsheets on one of the 
Apple Macintosh Classics, and these were transferred to the Sun workstations 
using ftp, and converted to PSTAR. For each CTD station, a master file of 
bottle data was created, containing all sample data, and the matching 
continuous CTD data from the firing file. Once the sample and continuous data 
were combined, salinity and oxygen calibration coefficients were calculated, 
and the I hertz data was recalibrated. All data were then reworked to ensure 
the calibrated salinity and oxygen data filtered through to the master sample 
file. 

All processing was carried out using Unix C-shell scripts, developed on the 
previous DISCOVERY cruise and all worked reliably. 

Additionally, on this cruise, CTD data from the Kerguelen Crozet Trough were 
formatted into TESAC messages, to supplement the XBT data sent onto the GTS 
(Global Telecommunications System). TESAC messages are composed of 
TEmperature, SAlinity and Current data, although current data is optional and 
was not sent in any of our messages. The message protocol (WMO Code FM-64V) 
allows up to 25 records of depth, temperature and salinity to define the water 
column. These data were selected from the two decibar averaged CTD data using 
an algorithm developed at NOS (National Oceanographic Service) in the USA, 
which uses changes in the property gradient to pick out data. Software written 
at IOS implemented this algorithm, and allowed the users to interactively de-
select chosen points or choose alternatives. These data were then formatted to 
FM-64V, written to floppy disk and transferred to the XBT personal computer 
(pc). On the pc, a version of the Seas software (modified at IOS), loaded the 
TESAC data into the MEET buffer, ready for transmission. Unfortunately, a 
request to Darmstadt for a new METEOSAT transmission id was not forthcoming, 
so TESAC data had to be transmitted at the same time as XBT data. To prevent 
loss of XBT data, TESAC messages were planned for periods when no XBTs were 
dropped; i.e. the mooring sections. To add insult to injury, after the first 
message had been sent (ctdl2349), the satellite transmitter developed a fault, 
preventing further data from being transmitted. Subsequent TESAC data were 
sent (along with the now beleaguered XBT data) direct to the RTH in Hamburg, 
with the routine meteorological observations submitted by the ship's officers. 
We await confirmation that these messages were received intact. Messages were 
formatted and sent for the following stations: 

ctdl2349 ctdl2364 ctdl2368 ctd 12369 ctdl2372 ctdl2373 ctdl2380 ctdl2381 
ctdl2383 ctdl2385 


Reconciliation of bottle and CTD data and CTD calibrations
(W.J. Gould/IOSDL)

The first task in the production of calibrated CTD data was the confirmation 
of the depths of closing of the multisampler bottles (Table 2). The 
performance of the sampler remained problematical throughout the cruise and 
the confirmation of sample depths was therefore important. Three information 
sources were used : 

1. Digital pressure/temperature meters 
2. Bottle salinities. 
3. Nutrient values.

Digital P/T meters were only used at 4 bottles and therefore could not define 
all levels. The nutrient values could, in areas of nutrient gradients, 
identify where bottles had fired in pairs but could not provide information on 
what that level had been. The bottle salinities were compared with those 
values (calibrated using a nominal initial calibration) in the firing file. 
The firing file is generated by the CTD and records values averaged for 5 
seconds either side of the bottle firing. Experience showed that the CTD-
bottle differences changed smoothly throughout the depth range of the cast and 
so in all but areas of very weak salinity gradient the salinity information 
combined with the other data allowed an unambiguous sequence of bottle firing 
depths to be established for each station. 

The discrete bottle oxygen and salinity values were then used to calibrate 
each individual station, using the series of PSTAR executives detailed in the 
CTD processing section. 

For salinity, grouped calibrations were established for each major work area 
(Enderby Basin, Princess Elizabeth Trough and Crozet/Kerguelen). Residuals 
between the calibrated CTD and the bottle salinities for these three groups 
are shown in Figure 3. All demonstrate a similar shape and one that is much 
like that established on RRS CHARLES DARWIN 62 (CONVEX) using the same CTD and 
similar data processing path. 

Figure 3*.	Residuals between calibrated CTD and bottle salinities

Similarly the CTD oxygen data were calibrated using the bottle values. The 
behaviour of the oxygen sensor is such that the recorded values are dependent 
on flow rate past the sensor. To reduce this effect, the discrete samples 
taken on the up cast were used to calibrate the CTD oxygens from the down 
cast. Matching was done on the basis of pressure. The up cast CTD oxygens were 
discarded. The algorithms used were as on DISCOVERY 199. These were found to 
give a poor reproduction of the deep oxygen profile and a modified algorithm 
developed by Brian King after this cruise was subsequently used to rework the 
calibrations. 

Two other comparisons can be made that shed light on the quality of the data. 

The digital temperature meters can be compared with each other (where they are 
paired) and in every case with the CTD temperatures from the firing files. The 
temperature meters had been calibrated and in what follows the results all 
apply to the calibrated data. 


Thermometer no.	Therm - CTD (Mean±SD) m°C	Number of obs.

   219		     7.1 ± 5.0			  26
   220		    -3.1 ± 2.6			  25
   238		    -1.6 ± 1.7			  24
   399		     1.6 ± 1.0			   7
   400		    -1.4 ± 1.4			  25
   401		    -3.8 ± 1.3			  25

The results of the comparison of paired thermometers are:
		
  219-401	     10.9 4.6			  26
  399-400	     0.7 1.6			   7

Similarly comparisons can be made between the CTD pressures and those recorded 
on the digital pressure meters. In this case the measurements were made over a 
considerable range of pressures and so we have investigated the pressure 
dependence of the differences. These are shown in the following two plots*: 

Clearly the behaviour of the pressure meters vis A vis the CTD is systematic 
and pressure dependent. The fact that the two meters have a pressure 
dependence of opposite sign suggests that the pressure dependent error is not 
in the CTD sensor. 

Finally a check was made of the mismatch between the water depth on each 
station measured by the echosounder and corrected for the assumed speed of 
sound using Carter's Tables and that calculated from the CTD pressure 
(converted to depth according to Saunders, 1981) added to the height above 
bottom measured by the altimeter. The mean difference (water depth - CTD 
depth) = 1. 1 ± 10. 1 m for the 24 stations for which data were available. In 
view of the fact that several of the stations were in frontal areas where 
Carter's Tables might be in error, the results are most encouraging. 


Bottle salinities
(S.R. Jones, W.J. Gould/IOSDL)

Bottle salinities were taken in order to calibrate the CTD and the 
thermosalinograph. Samples were contained in glass bottles sealed with push in 
polyurethane inserts and secured with a screw cap. 

Sampling in every case involved emptying the old sample, rinsing three times 
with the new sample and finally filling to the shoulder of the bottle, drying 
the neck with a tissue and sealing the bottle. In the case of the multisampler 
all external water drops were removed from the area around the tap before 
sampling began. 

The bottles were in crates of 24. This meant that for the thermosalinograph it 
was sometimes 4 or more days between a sample being taken and its analysis on 
the salinometer. For the CTD samples this delay between sampling and analysis 
was never more than 24hrs. Sample crates were kept in the lab with the 
salinometer for the sample temperature to equilibrate before analysis. 

The salinometer was the 1OSDL Guildline Autosal model 8400A with a Ocean 
Scientific International peristaltic pump. The unit was housed in the constant 
temperature laboratory. The laboratory temperature was set at 21°C and the 
bath temperature at 24°C. The salinometer was powered by a filtered mains 
supply that had been installed on DISCOVERY 198 to eliminate voltage spikes. 

The salinometer was standardized with ampoules of P120 IAPSO Standard 
Seawater. The method adopted was to standardize with a new ampoule at the 
start of each box, to seal the ampoule with 'Blu Tac' and then to use the 
remainder of the ampoule to restandardise at the end of each box. 

No problems were encountered with the operation of the salinometer. Its 
standardization remained very steady and there were no problems with cell 
fouling. 

The recorded standardizations are shown in the plot* below: 

The data show that with the exception of one standardization there was a 
steady trend in the values that amounted to a shift of 0.0003 during the 
duration of the cruise. This continues a trend seen towards the end of 
DISCOVERY 199. 

Duplicate salinities were taken from rosette bottles I and 12. Bottle 2 was in 
all cases closed at the same depth as bottle 1. An analysis of the differences 
show the following:

Bottle 1 - duplicate	0.0010 ± 0.0012
Bottle 12 - duplicate 	-0.0004 ± 0.0007
Bottle I - Bottle 2	0.0009 ± 0.0007

There seems to be a significant difference between the reproducibility of 
duplicates at the deeper bottle 1/2 level and at bottle 12. 

The differences between bottles I and 2 are also larger than might be hoped. 
Inspecting differences between the CTD data and the salinities from bottles I 
and 2 suggests that there is less scatter in the bottle 2 data, perhaps 
indicating an occasional leakage in bottle 1. 


Chemistry
(D.S. Kirkwood/MAFF)

Oxygen

Much of the first few days was occupied by efforts to get a satisfactory 
performance from the photometric end-point detector recently purchased from 
UCNW Menai Bridge by MAFF. Unfortunately, due to container shipment deadlines 
there had been no opportunity to test the instrument in the laboratory at 
Lowestoft. 

A major problem was that the instrument produced an output signal with an 
excessive noise-level sufficient to obscure anything meaningful that may have 
been underlying. We could find nothing amiss electrically or optically but are 
satisfied the noise is synchronous with the ship's motion. There was no 
alternative other than to revert to a visual end-point. Using the magnetic 
stirring and illuminating facilities of the UCNW instrument and manually 
operating the Metrohm 665 Dosimat, enabled titration to a visual end-point 
with starch indicator, somewhat less precise than the WOCE recommendations, 
but a reasonably satisfactory solution. 

Some problems were encountered during the earliest stations. A hand-held 
repetitive dosing pipette proved unequal to the task of dispensing a 
relatively viscous reagent. Its internal ratchet mechanism developed an 
intermittent fault before it failed completely, and a few suspect oxygen 
values are traceable to this period. After reverting to a simpler more robust 
pipette, not quite so convenient to use but one whose performance could 
readily be seen and felt to be satisfactory, the problem was overcome. 

Quality Control

The primary standard iodate solution used for standardizing the thiosulphate 
titrant was supplied by WAKO Chemicals GmbH, Neuss, Germany, and is guaranteed 
by the Sagami Chemical Research Center. (Lot No. TWP8499). 

The thiosulphate was checked on each occasion that analysis was carried out 
and its stability probably owes much to the fact it was prepared using high-
purity water and all operations were under artificial light. 

As a check on the overall precision of the method, the CTD multi-sampler 
filled twelve bottles at a depth of 1000 meters, and these produced oxygen 
concentrations in the range 4.21-4.24 ml/l. 

Given that the readability of the digital burette is 1 microlitre, and a 
typical titration consumes 500, this level of precision is as good as we are 
entitled to expect. 

Oxygen data

A total of 664 Winkler determinations were made.
Figures 4(a)* and (b)* show potential temperature/oxygen plots for Winkler and 
CTD oxygen respectively.

Figure 4*.	Potential temperature versus oxygen for a) Bottle oxygen data, b) 
		CTD oxygen data

Figure 5* illustrates the differences between these as a function of depth. 
Differences are most likely to be greatest at depths where substantial 
gradients occur; the distribution is consistent with this assumption.

Figure 5*.	CTD and bottle oxygen comparison on the Kerguelen-Crozet section 
		versus depth

Nutrients

A total of 921 samples of seawater were analyzed for nitrate, phosphate and 
silicate using the MAFF'SKALAR'continuous-flow auto-analyzer. 

Of these, 652 came from 29 CTD casts, and the remaining 269 were 'surface' 
samples in support Of PC02 and DMS measurements. (These were taken from the 
ship's non-toxic supply at approximately hourly intervals while steaming 
between 25 February and 14 March). 

Procedures

Samples were drawn directly from the CTD rosette bottles into 1-litre 
polyethylene bottles and were analyzed without filtration within one or two 
hours. The analytical methods used differ in some important details from those 
originally supplied by the manufacturer. 

In general, changes have been made to bring them into line with recent 
improvements in current practice; for example, the silicate method (based on 
that of Grasshoff, 1983) has a calibration slope almost independent of 
salinity and laboratory temperature fluctuations. (Full details of these are 
due to be published soon by ICES in the 'TIN11ES' series, Techniques in Marine 
Environmental Science, entitled 'Nutrients : Practical Notes on their 
Determination in Seawater'). 

The auto-analyzer's carousel uses 8-n-fl cups which are thoroughly rinsed with 
sample. Analysis was by single determination unless results appeared to be in 
any way 'oceanographically inconsistent', in which case repeats were performed 
to resolve the problem. (These were rare events, generally due to mild 
contamination of sample cups during handling). 

Silicate analysis was of great value in confirming sampling depth, given that 
the firing mechanism of the CTD multi-sampler suffered intermittent faults. It 
also resolved a problem of mis-identification in freon analysis, the residual 
sample in a syringe being readily attributable to a particular depth. 

Quality Control

During DISCOVERY 199 a bulk sample of typical seawater was stored under 
refrigeration in a polyethylene carboy. Mean concentrations for this QC sample 
were supplied before 

DISCOVERY 200 commenced, and regular analysis continued throughout the cruise. 

The means are as follows -

 	nitrate	   phosphate	silicate
D-199	28.85	   1.79		78.85
D-200	25.2	   1.74		80.2

Agreement in phosphate and silicate is excellent.
D- 199 reported a 'gradual decrease in nitrate' in this sample and at first 
glance the D-200 mean appears consistent with this, however, there is no time 
trend evident within the D-200 data.

Date	Nitrate	 Phosphate	Silicate
08.02	25.5	 1.70		80.4
09.02	25.8	 1.70		80.6
11.02	25.6	 1.74		80.3
15.02	25.5	 1.79		80.2
25.02	26.3	 1.76		80.6
04.03	24.6	 1.78		79.2
13.03	25.2	 1.69		80.3

This data suggests that the sample is now relatively stable and there may be a 
systematic discrepancy between IOS and MAFF nitrate calibration materials or 
techniques. This will be further investigated during DISCOVERY 201 and in the 
laboratory at Lowestoft. The lack of Certified Reference Materials in this 
field continues to be a serious drawback. 


CFCs 
(T.W.N. Haine/UEA, M. Krysell/U.Goteborg, A.J. Watson/PML, M.I. Liddicoat/PML)

The CFC system described here in brief was used to measure ambient atmospheric 
and dissolved marine concentrations of CFCs 11, 12, 113 and carbon 
tetrachloride (CCl4). The prototype instrument was based on a gas 
chromatograph used by the PML CFC group previously. The main separation 
element was a megabore fused silica column (DB-624), whose exhaust was 
delivered directly to an electron capture detector. Seawater samples were 
stripped of volatile dissolved gases by bubbling in a sparging tower. An 
unpacked trap was used to concentrate these compounds as they were liberated 
from the seawater sample prior to injection onto the column. The trapping 
temperature was between - 140°C and -180°C, maintained by placing the 
stainless steel loop in the headspace of a dewar containing liquid nitrogen. 
The trap temperature was raised to 90°C by immersion in hot water for the 
injection. The oxygen-free nitrogen gas used to strip the sample was treated 
by a hot palladium catalyst, then by a cold trap in the headspace of another 
dewar containing liquid nitrogen. The helium carrier gas was cleaned up by 
being passed over a short length of molecular sieve, immersed in liquid 
nitrogen. The ECD was calibrated by using samples of standard gas containing 
established proportions of CFCs 11, 12 and 113. A liquid standard was used for 
CCl4 during the first half of the expedition, and then marine air was used as 
an effective standard for the rest of the cruise. The analysis was semi-
automatic, controlled by an integrator which also provided data for a PC based 
chromatography package. By using a DB-624, precolumn trapped compounds which 
elute after CCl4 were cut from the main column and so the analysis time for 
each sample was 9 minutes. 

Few problems with contamination were encountered during the cruise. The 
syringes and taps used to draw samples from the water bottles were cleaned 
each day with detergent rinses. These syringes were also used to sample marine 
air from exposed, upwind parts of the ship. The results of an experiment where 
all the water bottles were closed at the same depth indicated that the CFC 
bottle blank from these was of the order of a few femto moles per litter Q 
orders of magnitude lower than surface concentrations). This exercise revealed 
that 2 Niskin bottles were causing slightly elevated levels, but after the 
springs had been changed no further problems were noted . 

Approximately 600 water samples were analyzed from 25 stations. Precision on 
water samples was of the order of 1-2% or 10 femto moles per litter, whichever 
is larger, and routinely better than 0.5% for gas samples. The analytical 
detection limit was of the order of a few femto moles per litter for each 
compound. In all of the stations analyzed, beneath the surface layers CFC 
loads were low, typically 20 times smaller than surface values. Near bottom 
elevation in CFC concentrations were noticed in several casts, although this 
was relatively modest in most cases. In the Crozet-Kerguelen section the 
bottom water revealed increased CCl4 levels, but there was often insufficient 
quantities of CFC- 11 to demonstrate a significant bottom enhancement in this 
species. This emphasizes the utility of measuring dissolved CCl4 
distributions, which allow the tracer dating technique to be extended back to 
the first couple of decades of the 20th century. Practically no CFC- 113 was 
observed in any intermediate or bottom waters (dating back to - 1973). Figure 
6 shows preliminary data from typical profiles from each section analyzed. On 
the steam east to the Princess Elizabeth Trough region an isolated station was 
occupied in order to compare with CFC data gathered from the same location 5 
years previously. 

A second, independent, CFC analysis system was used during the cruise for 
measuring the same four compounds as mentioned above. The two systems were 
largely identical, the main difference being that the second system did not 
have a pre-column in order to cut the chromatogram after CCl4. With a 70 m 
long DB-624 column it is possible to separate at least 20 currently identified 
C, and C2 halogenated compounds in 14 minutes, thus getting information on 
other anthropogenically produced halocarbons as well as a number of naturally 
produced ones. The lack of a pre-column, however, necessitates the use of 
temperature programming in order to empty and clean the column within 
reasonable time. The consequences of general importance are thus two: the 
sample throughput rate goes down (25 minutes per sample) and the sample-to-
sample precision goes down. A total of about 300 water samples were analyzed 
using this system during the cruise. No definitive results are yet available 
for presentation, since the concentrations have not yet been calculated. All 
general trends and features as described above can, however, be seen from this 
second data set as well. 

The good quality of the CFC data gathered on this cruise was considerably 
helped by the assistance of everyone on board in refraining from using 
aerosols and other products containing CFCs. 


Figure 6*.	Preliminary CFC data from typical profiles on each of the three 
		sections

Stable isotope and trace metal chemistry
(R.D. Frew/UEA)

A total of 690 samples were collected for analysis of stable oxygen and 
hydrogen isotope ratios. By combining stable isotope ratios with salinity 
measurements it is possible to distinguish water masses that have had their 
salinity changed by evaporation or precipitation from those that have been 
altered by freezing or melting. 

Two sets of sample bottles were used, 250 ml salinity bottles with plastic 
neck inserts and 150 ml sample bottles with rubber seals. 'Me 150 ml sample 
bottles were further sealed with paraffin 

wax. At 3 stations replicate samples were collected using both types of sample 
bottle to check for possible evaporation during transport. Analysis of these 
samples will commence on return to the laboratory. 

Surface particulate samples were collected underway by filtering water from 
the non-toxic supply through precombusted GF/F filters until the filter 
blocked. The filters were then frozen for later analysis on return to the 
laboratory. One I of the filtrate was also collected in polythene bottles and 
preserved with mercuric chloride. These samples will be analyzed for their 
nitrogen isotope ratios. Because the nitrogen isotopes are fractionated by the 
biota, comparison of the ratio in the particulate matter with that of the 
dissolved nitrate gives an indication of the extent to which the productivity 
is utilizing the available nutrients. Fifty particulate and forty-eight 
nitrate samples were collected. 

Trace metal samples were collected from profiles in the Princess Elizabeth 
Trough, just west of Crozet Island and north of the STC. A single sample was 
taken from each CTD cast in the PET and Kerguelen basin, these were taken from 
a 10 1 'GO FLO' bottle deployed on the CTD-rosette in position 22. For the 
profiles samples were drawn from the Niskin bottles as well. A total of 94 
samples were collected. These samples will be analyzed primarily for Cd to 
compare the Cd/P relationship through the different water masses sampled. 
Other biologically utilized trace metals (Ni, Cu) will be determined depending 
on the extent of contamination from the rosette and Niskins. 


PC02
(J. Robertson/UCNW)

On the cruise pCO2 was measured using a gas chromatograph and showerhead 
equilibrator. Air for the system was supplied by a compressor and hydrogen was 
fed in via copper pipes from the gas bottle store. The intention was to use 
the installed piped gas supply, however pressure testing on the hydrogen line 
whilst in Cape Town showed a small leak that could not be found so before 
sailing extra copper piping was used to connect the deck laboratory to the gas 
bottles. 

The equilibrator was placed in the water bottle annexe as this kept it close 
to both the de-airated non-toxic supply and the GC in the deck laboratory. The 
water bottle annexe was kept cold, with auxiliary heating switched off 
enabling us to keep the temperature in the equilibrator as close as possible 
to the in situ temperature. The programme for the system had a cycle time of 
13 mins. During each cycle two measurements of the PC02 in the water were made 
bracketed by standard and marine air measurements. Marine air was 
approximately 355 ppm ± 2 ppm as measured throughout the cruise with no 
discernable change with latitude which is as expected in the Southern Ocean. 
The equilibrator caused a few problems as it kept filling up with water, this 
was controlled by keeping a close watch on the equilibrator and emptying it if 
necessary. There was an average increase in temperature of 1.5 degrees in the 
equilibrator from in situ temperature which is four times that experienced on 
previous cruises where this system has been used. This increase requires a 
substantial correction to the data once it has been processed (reducing the 
observed value by approximately 20 ppm). After about one week of constant use 
one motor on the system over-heated and had to be replaced. The motor driver 
board in the controller was also replaced following some resoldering by one of 
the RVS engineers on board. 

Figure 7*.	Measured pCO2 values (a) outward leg, (b) return leg

The system was working almost continuously giving a PC02 value approximately 
every 6 minutes, this data is only preliminary and further calibration using a 
running standard and temperature corrections will be necessary. Initial 
calculations show that the pCO2 as measured in the water was mainly below 
atmospheric levels for the majority of the track covered by approximately 10 
ppm with the largest deficit being seen as the ship got closer to the ice-edge 
(100 ppm). The measured pCO2 values (after calibration) for the outward and 
return legs of the cruise are shown in Figures 7 (a)* and (b)* respectively. 

An underway flow-through fluorometer was requested for the cruise in order to 
complement the measurements of both pCO2 and TCO2. Unfortunately this was not 
provided which caused a setback to part of the interpretation of the data 
collected. As an alternative, hourly water samples were filtered for 
chlorophyll content and the filter papers frozen immediately. These samples 
will be returned to PML for fluorometric determination of chlorophyll content. 
In addition to hourly chlorophylls, nutrient samples were taken and analyzed 
on board. 


TC02
(J. Robertson/UCNW)

Total C02 is a measurement of dissolved inorganic carbon and represents 
carbonate, bicarbonate and unionised species of C02. A thermodynamic 
relationship exists between TC02 and pCO2, enabling the two measurements to be 
used to calculate both the alkalinity and pH of the seawater (although with 
reduced accuracy compared to direct measurements). 

The analytical system consists of two main components, the extractor unit and 
the coulometric detector. A sea water sample is filled from the non toxic 
supply and is fed under gravity to a calibrated pipette. This is discharged 
into a stripping chamber where orthophosphoric acid quantitatively converts 
the DIC to C02. The C02 is purged by a nitrogen carrier gas flow into the 
reaction cell where it is coulometrically titrated to an end point. 

It was originally intended to measure TC02 in continuous underway mode to 
parallel PC02 but several major problems made this impossible. The coulometer 
chemicals and the WOCE TC02 standards of known carbon content were stored in 
the deck lab chill store during transit from the UK. At some time during this 
period the temperature fell from the nominal 10°C to below O°C and the 
standard bottles cracked. Apart from the financial loss, which was in excess 
of E500, the loss of standards meant that the quantity and quality of the 
science originally proposed for this cruise and the earlier cruise (DISCOVERY 
198) was completely disrupted. The coulometer chemicals would also have been 
subjected to freezing temperatures and it is not certain what effect this had 
on the solutions. The chemical suppliers were contacted once freezing was 
suspected and they explained that the chemistry of the solutions may be 
sensitive to such a temperature change. These factors forced a change to 
discrete sampling from the non toxic supply and the analysis of up to 5 
replicates of each sample to give a measure of confidence in analytical 
precision of the technique. Variations in the quality of the electrical supply 
which appeared to be a problem on DISCOVERY 198 were not evident on this 
cruise and precision within the bottles sampled was increased (typically 1 
S.E. = ± 1.5 µmol/kg) over that experienced on DISCOVERY 198. In discrete mode 
the system allowed, at best, a sample throughput of twenty samples a day which 
seriously reduced the spatial resolution of surface mapping compared with that 
achievable in underway mode. Nevertheless a number of discrete samples were 
processed whilst underway and two shallow CTD casts, one at the most southerly 
point of the cruise and another on the way back further north, were also 
sampled. On returning to PML the data will be recalculated to take into 
account calibration of the pipette volume and corrected thermosalinograph 
data. 


Dimethyl sulphide, dimethylsulphoniopropionate and low molecular weight 
halocarbons 
(J. Robertson/UCNW)

Measurements of DMS, its precursor, DMSP and halocarbons (e.g. methyl iodide, 
bromoform, chloroiodomethane) were made during passage, to assess surface 
water distributions and sea-air fluxes. Discrete samples were taken from the 
ship's non-toxic supply (non de-aerated) at regular intervals and analyzed on 
two separate Gas Chromatographic (GC) systems. Water samples were purged with 
nitrogen gas (30 mins.) to strip out the dissolved trace gases, which were 
subsequently cryofocussed using liquid nitrogen vapour at - 150° C. After 
thawing, the samples were injected into the GCs. For halocarbons, the sample 
was loaded onto a megabore DB624 column with a 3 stage temperature programme 
and were analyzed using an electron capture detector. DMS was resolved using 
an isothermal Chromosil 33.0 column and quantified by flame photometric 
detection. Non-volatile DMSP was resolved into two fractions, particulate and 
dissolved, operationally defined by AP25 depth filters of nominal retention, 
1.0 pm. Filter and degassed filtrate were each put into ground glass stoppered 
bottles with 10M NaOH. These were stored in the dark for at least 12 hours to 
allow for complete hydrolysis of DMSP, which produces DMS. The samples were 
then analyzed as described above. Chlorophyll samples were also taken. These 
were frozen and will be sent back to the UK for analysis at UEA. 

Trace gases and DMSP were also measured in two 200m depth profiles (D 12357 
and D 123 85). Additional samples were taken for Dr. Tim Jickells, for the 
determination of iodide/iodate ratios. 

The levels of DMS in surface waters were low, with a mean less than the 
currently estimated global average. This is a little surprising, considering, 
not only the seasonal cycle that we have found in the northern hemisphere at 
similar latitudes, but also the very limited, published data for Antarctic 
waters. Generally speaking, concentrations of DMS and DMSP were lower in the 
southerly, colder waters, with marked changes associated with major oceanic 
fronts (Figure 8°). The depth profiles showed shallow surface maxima, with very 
sharp decreases in concentration, coincident with the thermocline. Further 
data analysis is required for the large number of halocarbons measured, but 
preliminary assessment shows significant trends in Mel and CHBr3. 

This was a successful cruise with only minor equipment problems. Fortunately 
it had been possible to do a Zodiac transfer of a single detector sulphur GC 
from JAMES CLARK ROSS to DISCOVERY in December 1992, as the existing DISCOVERY 
dual detector instrument had suffered terminal damage. The UEA liquid nitrogen 
plant worked successfully, on its second cruise and produced ample supply for 
UEA, the PML Freon group and Mikael Krysell. 


Figure 8*.	Surface concentrations of DMS and DMSP

Current meters and moorings
(J.W. Read/MAFF, I. Waddington/IOSDL)

Figure 1(c)*.	Chart showing current meter mooring positions

A total of 57 Aanderaa recording current meters were prepared and supplied for 
this cruise, 49 by MAFF Directorate of Fisheries Research (DFR) and 8 by 10S 
Deacon Laboratory (10SIE)L). 

All the 35 RCM4s and 5s from DFR were powered by standard Aanderaa PP9 
batteries and set to run at I hr intervals with divide by 8 rotor counters. 
During set up and pre-deployment testing of the RCM5s it was found that, in 
one meter, a rotor counter magnet and ball race had become detached from its 
holder on the rotor counter and was 'stuck' to the rotor magnet through the 
end plate of the meter. From the colour and serial number it was obvious that 
this counter had been fitted recently, probably immediately before the cruise, 
and that two spares supplied were also faulty. All other similar coloured and 
numbered units were checked; a further 4 were found either loose or 
inadequately glued. All were carefully reglued with Araldite. Some earlier, 
different coloured, units were checked and were found satisfactory. A message 
was sent to Aanderaa via their UK agents, and a reply received stating that 
the assembly should be held together with 'Loctite' and that only a severe 
jolt will free the components. This explanation could hold for the fitted 
units but the two spares could not have been subjected to sufficient shock. 
The opinion on the ship was that 'Loctite' is not appropriate in this case and 
Aanderaa should revert to an epoxy type adhesive. An electronic failure of an 
older rotor counter was also found during the final preparation using, as 
usual, the Aanderaa check list. This was exchanged for one of the repaired new 
units. 

All 22 RCM 7s and 8s from DFR and IOSDL were fitted with Al Marketing Lithium 
battery packs, and as these are slightly magnetic they were fitted as high up 
in the instrument as possible, to reduce any effect on the compass, and each 
instrument was compass calibrated when already fitted with its deployment 
battery. The 8 old style DSUs were fitted with new batteries immediately 
before starting. All were set to run at 1 hr intervals. 

Sensors

All instruments were fitted with the standard -2.46°C to +21.48°C temperature 
in Channel 2. In Channel 4, 26 had the Aanderaa 'Arctic' range of -2.5°C to 
+5.0°C, and 22 of various other ranges. In addition 11 were fitted with 
pressure sensors in either Channel 3 or 4, and 2 with conductivity sensors in 
Channel 3 of range 30-40 mmhos. 

Moorings

Two arrays consisting of a total of 16 moorings were deployed. All designs 
were run through the knockdown calculation program 'MOOR', to optimize 
distribution of available buoyancy. The 14 6 upper bottom' were designed and 
supplied by DFR and consisted of 2, 3, or 4 Aanderaa recording current meters, 
10 mm Marlow Ropes KT3 Kevlar, and supported by various numbers of pairs of 
Benthos 18" or Corning 17" glass spheres. Each Aanderaa was fitted with a pair 
of I meter Kevlar strops, to ease insertion into the mooring. 

The two 'full depth' moorings were supplied jointly by DFR and IOSDL with the 
detailed design by IOSDL, and consisted of 7 or 8 Aanderaa recording current 
meters, 6 mm jacketed steel wire and 10 mm polyester for the upper section and 
10 nun KT3 Kevlar for the lower section. A set of 20 Benthos glass spheres was 
inserted between the upper and lower sections to reduce the tension in the 
mooring and to support the mooring in the case of loss of the main buoyancy 
unit, a 48" IOS steel sphere. 

All moorings were laid buoy first, over the stem from the IOSDL supplied 
double barrelled capstan winch, using one of the stem cranes to support a wide 
sheave. The failure of the other stem crane before sailing meant that the 
gantry was used to deploy the buoyancy array at the start of each mooring. Two 
methods of deploying the release and the lower portion of the mooring were 
tried. The initial design with the acoustic release (A/R) 23 meters below the 
bottom meter meant that a 20 m slip rope was required to get the release 
safely in the water. This system worked well for the 'Mors' releases but fears 
that the rope could tangle more readily on the CR200 units led to the moving 
of these units up, to I meter below the bottom meter, with both the 23 m 
Kevlar strop and the 20 m wire below. This enabled the A/R to be winched into 
the water with the bottom meter and the rig to be released from the deck. 

All ropes used in the full depth mooring were 'stretched' and measured at 
their deployed tension before use to accurately ascertain the deployed length 
of these moorings. The difference between lab and loaded measurement (5%) of 
the DFR supplied Kevlar in these tests was used as a conversion factor for all 
other Kevlar lengths. 

The mooring details, with instrument numbers, depths and positions are listed 
in Table 3, and general rig diagrams are shown in Figure 9*. 

Figure 9*.	General current meter mooring diagram

Figure 10*.	Moorings in the Princess Elizabeth Trough

Five moorings were laid across this section, covering the water column up to 
2500 m, from a maximum depth of 3700 m using a total of 13 RCM5 instruments. 
All moorings were fitted with new Mors RT661cs acoustic releases in case ice 
cover in this area in 1994 prevents recovery. 

Figure 11*.	Moorings on the Kerguelen-Crozet section

Eleven moorings , including one west of Crozet, were laid. The 9 'upper 
bottom' type covered the water column up to about 1800 m and the 2 full depth 
up to 300 m. Three were fitted with Mors RT661cs acoustic releases, the 
remainder with CR200 units, in both single and double configuration. 


Acoustic releases
(N.D. Pearson/MAFF)

9   Mors RT661CS
10  IOS CR200 supplied by MAFF
4   IOS CR200 supplied by IOS with single pyro

Mors

One Mors unit failed immediately its batteries were fitted. It drew excessive 
current because the 50 V inverter had failed causing the 50 V supply to rise 
to 90 V. Components in it were overheating and in danger of damaging the 
circuit board. As there were no spare electronic parts available, the unit 
could not be repaired. The remaining eight units worked in the lab and were 
all successfully tested under pressure. The batteries were arranged such that 
all six were available to the receiver and motor but only two of the six were 
available to the transmitter. The transmitter with its 50 V inverter was felt 
to be the least reliable part of the system and this battery arrangement 
leaves four batteries for the receiver and motor should the transmitter or 
inverter fail and draw excessive current. When attempting recovery, the Mors 
release should be commanded to release even if it cannot be communicated with 
although recovery will have to rely on visual location only. 

Communication with the Mors when wire-testing was better with the IOS PES fish 
than with the dunking transducer. Communication from ship to release was very 
reliable, as demonstrated by turning the pinger on and off, but communication 
the other way was very dependent on weather and bow-prop activity. When the 
current meter rigs were laid, good ranges were obtained out to 4600 m with the 
ship steaming away at 12 knots. At shorter ranges, the diagnostic gave 
consistently reliable results. With one Mors release at 3000 m depth and the 
ship 4000 m away giving a slant range of 5000 m, better results were obtained 
with the dunking transducer. Eight out of ten ranges obtained were reliable 
and two of three diagnostic measurements were good. Weather conditions were 
good at this time. 

CR200

All 14 CR200s were fitted with batteries and bench tested. One MAFF unit had a 
short circuit capacitor in its transmitter which was replaced. Some of the IOS 
supplied units showed signs of irregular counting in the release circuit and 
were therefore modified. The fifth CR200 wire-tested failed to fire its 
puffers. There was a consensus that the problem might be the new lithium 
batteries in the pyro-fire circuit. This type of battery can develop a 
passivation layer which reduces its current capability until the battery has 
been supplying current for some time. POL have modified their CR200s so they 
multiple-fire the pyro to get over this passivation problem. All MAFF CR200s 
were then fitted with a new firing circuit which fires the pyro every few 
seconds as long as the release signal is sent. A pair of much larger D size 
lithium batteries were fitted into each MAFF release to increase the pyro 
current capability. 

The CR200s supplied by IOS were not fitted with the new pyro circuit, instead 
two units were fitted with an MN1 604 manganese alkaline battery and multiple 
lithium packs were also fitted according to the space available. Although 
these four units were fitted with a single pyro connector, batteries were 
fitted to both relay contact circuits as the wiring was paralleled at the 
connector. There should be sufficient battery power on these IOS units to fire 
the pyro first time, but should it not fire first time, it will be necessary 
to reset the firing circuit with a short burst of 320 Hz and repeat the 
release frequency. 

As a result of these modifications all the releases had to be wire-tested 
again and two units failed; one failed to give the release indication and the 
other came on in double ping mode. Investigations of these two failures showed 
that one unit de-sensitized itself while transmitting at 2 Hz so that it could 
not recognize the release signal and the other unit was found to respond to 
almost any frequency. Both these problems could be associated with the 
bandpass tone filters which require careful setting-up in the lab at two 
temperatures and it was felt inappropriate to tamper with them at sea. 

The one spare set of electronics carried was fitted in place of one of the 
faulty units. As an exercise, this unit (2187) was fitted with another new 
design of release circuit which minimizes the peak currents drawn from the 
battery. This unit could not be fitted with the repetitive pyro fire circuit. 

Moorings 93-11 to 93-17 with CR200 releases were set pinging and watched until 
they landed on the seabed. The pingers stuttered on both the full depth 
moorings due to the shock load on the release relay of the heavy anchor but 
release was not initiated. 

CR200 recommendations

A circuit was designed which would dispense with the pyro relay but still 
retain the advantage of electrical isolation between the pyros and the rest of 
the circuitry. Pyros can be fired by a mechanical shock to the release and 
this represents a significant danger and nuisance. It is recommended that this 
circuit be developed and fitted subject to finding room for it. The new 
circuit minimizes the peak currents and controls the relay on time better than 
the original circuit. It is important to reduce the peak currents taken from 
the receiver battery as otherwise its voltage can fall significantly which can 
cause circuit malfunction. It does not have the repetitive-fire capability, 
the need for this mode should be removed by fitting an appropriate type of 
pyro battery, probably manganese alkaline which will be cheaper and safer. 

Mors recommendations

As has already been mentioned, the Mors releases are able to hear 
transmissions from the ship in poor weather conditions but the ship's ability 
to hear them is a function of weather and bow-prop activity. More use could be 
made of the pinger as this can be seen on the waterfall display and Simrad 
EA500 under poor conditions. The pinger could pause and shift phase according 
to commands received. For example, the pinger could pause when the window 
command was received, re-start with a phase change when the release command 
was received and have a further phase change when the release motor completed 
its travel. If the release command were not received within the 60 s window 
period, the pinger would re-start without a phase change. The diagnostic 
command indicates battery voltage and verticality. This could also modify the 
pinger by phase changing the pinger in proportion to the voltage; advancing 
the phase if the unit is vertical, retarding the phase if the unit is 
horizontal. Once the pinger has started it continues until commanded to stop. 
It should have a time-out so it automatically stops after say 30 minutes. The 
options are endless, discussions must take place with Mors and IOS to agree on 
a specification. Hopefully Mors will accept that their system does need 
improvement in the deep sea. As the release uses a microprocessor, there 
should be no reason why these kind of changes should not be possible. 

The six screws which attach the release hook to the end-cap have a screwdriver 
slot. These screws are inserted with a locking compound and therefore will be 
difficult to remove. They should be replaced with hex or socket head types. 

The Simrad EA500 display updates every six seconds. For pinger work it would 
be desirable for the update rate to be increased to the actual pinger rate. 


Bottom Pressure Recorders
(P.R. Foden/POL, G.W. Hargreaves/POL)

Two POL Bottom Pressure Recorders (BPRs) were deployed on the Kerguelen-Crozet 
mooring line at ADOX positions 9307 and 9316. They were both at 3615 meters ± 
5 meters, uncorrected depth and positioned almost at the extreme ends of the 
mooring array. There are three pressure channels and three temperature 
channels, recording integrated count every 15 minutes. The BPRs are self-
contained and released from the bottom by a command to either a Benthos or 
CR200 acoustic release. 

Mechanical detail

Figure 12*.	Schematic diagram of Bottom Pressure Recorder

Figure 12* shows a schematic diagram of the instrument. Its dimensions are 
approximately 1.4 meters diameter and 1.2 meters high. The frame locates on a 
disposable steel ballast frame which is jettisoned for final recovery by a 
twin action titanium release assembly. On deployment from the ship the 
complete system free falls at 1 meter/sec from the sea surface to the seabed. 

The BPR consists of a main logger tube, containing power supplies and the 
electronics, four Benthos 17" glass spheres for buoyancy and two separate 
acoustic release systems. The primary release system is a Benthos XT6000 in a 
10" glass sphere with an external five-year lithium battery pack. The back-up 
release is a CR200 fitted with a high security relay, overcoming the CR200 
problem of pre-release when subjected to shock. Both releases fire pyros 
connected to a titanium release mechanism retaining the steel ballast frame. 
The descent or ascent can be monitored using the Benthos transponder and 
DS7000 deck unit to give direct slant range or the CR200 to give displays on 
the Simrad echo sounder and IOSDL waterfall display. 

Both BPRs are fitted with flashing strobe lights, a radio beacon and a forty-
foot rope stray line to aid recovery. The flashing lights and radio beacon are 
activated by pressure switches which switch on at the sea surface. The stray 
line can be grappled and used to lift the BPR out of the water and onto the 
deck during the recovery process. 

Instrument Electronics

Sea pressure and temperature signals are recorded by the logger onto solid-
state memory. The three pressure sensors are clamped in an aluminum block 
connected to the endcap which acts as a heat sink and keeps them at the same 
temperature as the external sea water. The electronics consists of an accurate 
timebase, a six channel frequency counter card, a 16 bit microprocessor card, 
and a 4 Megabyte EPROM (Eraseable Programmable Read Only Memory) card. The 
pressure sensors are two Paroscientific: Digiquartz and a Quartztronic. All 
three have internal temperature sensors and these together with the pressure 
signals are recorded on the six channel frequency counter board. 

The loggers are set up for 15 minute integration periods and each scan is 
'time-tagged' and stored in a 28 byte array in the EPROM memory. There is 
storage capacity for 149 796 (15 minute interval) scans or > 4 year's 
deployment. The microprocessor is powered up for about I second each scan and 
then goes into 'sleep' mode in between, ensuring maximum conservation of 
power. The power is supplied by a large lithium battery pack supplying 14 
volts, the programming voltage for the EPROMs (12.5 volts) is supplied by an 
onboard voltage inverter logger, ensuring operation down to a battery voltage 
of 6 volts, maximising battery life. 

BPR Launches

Both BPRs were deployed using the CTD winch located on the starboard side. 
11igh winds and a considerable swell prevented the use of the aft 'N frame to 
deploy them as originally planned. Both deployments went smoothly despite the 
weather conditions. Additional short rope strops were used to lift the frames 
due to the limited height available underneath the gantry. A plastic toggle 
was used to release the strop once the BPR was in the water, and two steadying 
lines used to stop the frame swinging. The BPRs were both monitored down to 
the seabed using the CR200 and the waterfall display. The Simrad EA500 was 
also used on a five-times multiple of the ping repetition rate. Both display 
methods worked well but better contrast on the waterfall display could 
probably have been obtained by altering the colour pallet. This does not seem 
to be a simple process and it was easy to make the display disappear. 

This is the first time that this configuration of logger has been used and the 
pressure sensors are mounted internally. The pressure sensor diaphragms are 
buffered from the sea water by tubes filled with silicone oil of the same 
density as sea water. The external plastic fittings for the pressure sensors 
had been left behind and new ones were expertly made by Colin Dav from RVS.

There was some doubt about one of the Swagelock fittings leaking oil in logger 
No. 1 and so the logger was pressure tested to a maximum depth of 1000 meters 
for an hour with no leaks. The oil is thought to be from when the fitting was 
originally filled and was inside the sealing olive nuts. 

Both deployments were most satisfactory and were correctly sited at 3615 
meters as accurately as possible (± 5 meters). 


ADCP
(J. Brown/MAFF, M.D. Sparrow/UEA)

Several hours after departing Cape Town the ADCP was calibrated whilst within 
bottom track range. The Aghulas current, with speeds of up to 100 cm s-1 was 
detected late on day 37 (Figure 13*). 

Figure 13*.	Plot of ADCP while crossing the Agulhas Current southbound

Two days out a data transmission problem arose, attributable to a loose PC 
board or connector, although the specific cause was not determined and there 
was no recurrence. Resulting from this, the sync cable from the gyro to the 
ADCP deck unit was found to be disconnected from 1800 day 39 to 1050 day 42. 
The fault wasn't detected as the default gyro reading was almost the 
reciprocal of the course traveled. During the southward track, ending on day 
48 and blessed with a following wind, data return appeared good with 
penetration often to 450 m. At this point, the opportunity was taken to make a 
calibration run. On the eastward leg to the Princess Elizabeth Trough (PEI) we 
again had a following wind and good data return. For a large part of the work 
in the PET conditions were favourable, but during the northward leg to the 
Crozet/Kerguelen site we steamed into the wind and the data quality was 
severely reduced, with the exception of that collected during CTD and mooring 
work. Bottom tracking was performed as we passed Heard Island, to the west of 
Kerguelen and also south of Crozet. The quality of data was not ideal. As the 
wind dropped on the return leg to Cape Town the quality of the data was much 
improved. 

Evidently the instrument is severely limited when steaming into the wind or 
sea and apparently at a wider arc than the oft quoted ±30°. It may be that the 
installation of an automatic bleed valve for the transducer well, might 
provide some improvement. 

Before a complete assessment of the data can be made gyro offset errors 
derived from the Ashtec system need to be applied and the data thoroughly 
screened, but at this point there is no reason to suspect data quality, head 
winds and sea-state excepted. 


Support services and routine environmental monitoring

Expendable Bathythermographs (XBTs)
(N.P. Holliday/IOSDL)

Throughout the cruise XBTs were launched six times per day (Table 4), except 
during the sections where the moored arrays were deployed. The majority of the 
probes were the T7 (760 m) type, but some of the deeper T5 (1800 m) type were 
launched at points of specific interest and when the ship was proceeding at 
the slower speed required (5 knots). The XBTs were launched from a Sippican 
Corporation hand launcher belonging to RVS, usually from the rear comers of 
the afterdeck. If the weather conditions were unfavourable or unsafe they were 
launched from just outside the Boatswain's workshop. The launches were 
controlled by a Bathy Systems SA8 10 controller and deck unit supplied by the 
SESU Hydrographic Office, Taunton, situated in the plot room and which used 
the Bathy Systems XBT Program version 1. 1. The unit controlled the launch and 
logged the data, along with header information such as water depth, position 
and surface temperature (entered by the operator). It could also be used to 
list isotherms, to identify critical inflection points in the data, and to 
generate BATHY messages for transmitting to the GOES satellite and eventual 
insertion onto the GTS network. 

The data were logged by the deck unit as a list of voltages at 10 Hz and probe 
depth was calculated based on time. At regular intervals the data were 
transferred using a 3.5 inch diskette from the deck unit to the RVS level C. 
Each profile then underwent a series of processes to format and archive the 
data and to improve the final quality by selective filtering. Header 
information was edited with data from bestnav to ensure the most accurate 
position for the launch time was used. Sections along constant or similar 
latitude and longitude were plotted to reveal various structures including 
fronts and horizontal layers. 

A total of 152 XBTs were launched, leading to 123 good profiles. Of the 
failures, 7 were due to the wire breaking before the profile was finished, 11 
were due to stretched wire, 8 were due to operator error, 1 was due to bad 
weather and 2 probes just gave a spurious reading for an unknown reason. The 
wire stretching and/or breaking was the biggest problem; some occurrences may 
have been down to the operator not holding the launcher correctly (it should 
be pointing 'down' the wire to avoid snagging on the tube), but it is likely 
that most were the result of the wire not spooling off correctly. When it 
occurred, stretching led to spuriously high temperature values being logged 
and was often not recognized until the data were processed and plotted. The 
stretching may have been a result of bad handling of the boxes of XBTs during 
loading, particularly as one whole box (12 probes) was faulty. The operator 
errors, usually failing to follow the procedures correctly, lead to profiles 
never being logged by the deck unit and in one case, lead to the profile being 
lost. The problem was often due to poor communication between the afterdeck 
and the plot room, particularly when the RVS radios were unavailable or 
faulty. If a problem was recognized with a profile at the time of deployment, 
another probe would be launched straight away. The boxes of XBTs were kept in 
the water bottle annex which is reasonably cool, to avoid the 'thermal shock' 
problem encountered during DISCOVERY 198. 

Weaknesses in the Bathy System XBT Program and the deck unit became apparent. 
The time logged is the time when the operator confirms the header information 
entered by hand, and it may be up to 10- 15 minutes after this time when the 
probe is launched, particularly if there were no radios or if conditions were 
difficult. It was necessary to make a note on the log sheet of the launch time 
so the correct GPS positions could be added later. Another problem resulted in 
one profile being lost; if the wrong key is pressed after the profile is 
finished but before inflection points are calculated then the drop is 
'aborted' and the data lost. 

For the first three weeks each successful profile had inflection points 
calculated and a BATHY message generated which was transmitted to the GOES 
satellite for insertion onto the GTS. However the transmitter failed to work 
after 27 February when a faint but ominous burning smell was detected in the 
alley between the plot room and the CT Laboratory. After that date, 2 profiles 
per day were selected and the BATHY messages telexed to the RTH in Hamburg 
with the regular meteorological observations. 


Thermosalinograph (TSG)
(N.P. Holliday/IOSDL)

Surface salinity and temperature were continuously measured using a Falmouth 
Scientific Inc. (FSI) shipboard mounted thermosalinograph located in the 
hangar. Bottle samples for salinity were taken every 4 hours from the non-
toxic sea water supply and used to calibrate the conductivities from the TSG. 

The TSG uses the non-toxic seawater supply which is drawn in 3 m below the 
surface and piped up to a header tank located opposite the winch control room 
at the hangar deck-head level. The header tank is maintained at a constant 
level by adjustable intake and outflow and provides an even flow for the TSG. 
For one short period (30 minutes) during rough weather the header tank became 
empty and the TSG was filled with air bubbles which meant no good data were 
logged for that period. The TSG itself has an Ocean Conductivity Module (OCM) 
and two Ocean Temperature Modules (OTMs); one fitted within the flow-through 
sensor holder (housing temperature) and another on the suction side of the 
non-toxic intake (remote temperature). The housing temperature is used to 
determine salinity. 

Data are passed from the OCM, and OTMs via an RS-485 data interface to a 
Viglen 386sx. 25 MHz personal computer (pc) where they are formatted and 
passed to Level B at 5 Hz. The programme used is called 'surflog' and 
continually displays the last 3.27 hours of data as line graphs. Data were 
read from the RVS files in 24 hour segments each day, appended to the tsg200 
master file and an averaged file generated. After each box of 24 bottles was 
completed and analyzed, the bottle samples were merged with the averaged TSG 
data and the mean and standard deviation between the salinity data computed. 
Plots of uncalibrated TSG temperature and salinity and bottle salinity against 
time were generated. 

The TSG salinity is slightly offset from the underway bottle salinities and so 
the TSG needs to be calibrated. Originally it was thought there might be a 
linear relationship between the temperature and the salinity offset, but 
further comparisons revealed that the best approach was to calculate the 
bottle conductivities (using housing temperature) and determine the 
relationship between the conductivity difference and conductivity. A least 
squares regression was performed on the conductivities producing the best 
linear fit, and the coefficients used to recalculate the TSG conductivities 
and hence salinities. 


Satellite imagery and sea ice intelligence
(P.D. Cotton/JRC)

Satellite imagery

Real time satellite imagery of the sea/ice surface was available on DISCOVERY 
200 through the use of a Dartcorn Macsat Receiver, and associated software 
installed on a Macintosh PC. The primary use of this equipment was to acquire 
sea ice information in the area where it was most likely to affect mooring 
operations, at the southern end of the Princess Elizabeth Trough. 

Images were routinely acquired 4-5 times per day from the NOAA series of 
satellites (National Oceanic and Atmospheric Administration, a US government 
funded agency). These satellites transmit both an infra-red and a visible 
image of the earth's surface, and the software on the Macintosh is 
theoretically capable of capturing both of these images. However, because of 
problems encountered on earlier cruises, only one image (infra-red or visible) 
was acquired per satellite pass. 

Although the primary use of Macsat was its contribution to sea-ice 
intelligence, a number of infra-red images were acquired in the region of the 
sub-tropical front, and the surface temperature signature of this feature 
could be clearly seen in these. In addition, in an area of the world where 
accurate meteorological forecasts are few and far between, images showing the 
location and size of local weather systems were of some help in the short term 
planning of operations sensitive to weather conditions. 

Despite some initial doubts as to whether enough clear weather would be 
experienced to enable images of the ice-edge to be obtained, such images were 
regularly acquired. On average at least one good definition of ice edge was 
received every two days, once the scanning area of the visible satellites 
covered an appropriate region (whilst DISCOVERY was within -10° latitude of 
the ice edge). 

The real value of carrying a satellite receiver on a ship is in the 
information it can provide in real time to the scientist. On this cruise, 
satellite images were acquired regularly and reliably through the Macsat 
receiver, which fulfilled this requirement well. 

Sea Ice Intelligence

The planned deployment of moorings at the southern end of the Princess 
Elizabeth Trough, close to the seasonal ice-edge, meant that accurate sea ice 
intelligence was required both before the start of the cruise and during the 
journey down to the mooring area. In addition, whilst sailing in areas of 
possible sea-ice, the ship's Captain is required to have all forms of sea ice 
intelligence that are available. 

Such information was acquired through a number of routes. Weekly sea-ice maps 
acquired from the US Navy/NOAA Joint Ice Centre were faxed down to the ship 
from the James Rennell Centre in Southampton. In addition, estimates of the 
ice edge analyzed from Passive Microwave Satellite data and from the altimeter 
on board the European Remote Sensing satellite ERS-1 were available on average 
once every three days (these two data sets were provided by colleagues at the 
Mullard Space Science Laboratories). Ice edge co-ordinates were also sent 
direct to the ship from the UK Meteorological Office. Images from Macsat 
complemented these sources of information. Local authorities in South Africa 
had been contacted with a request for information, but in the event they were 
unable to provide any significant help. 

Icebergs were first encountered, unexpectedly early, at 47° 40'S 17° 50'E- on 
day 041. Icebergs (on average 10-20m high and 50- 100m long) were subsequently 
regularly in view up until our final departure from the mooring area in the 
Princess Elizabeth Trough (day 057). The edge of continuous sea-ice 
(approximately 7-9/10 concentration) was encountered at 65° 06'S, 85° 19'E on 
day 056. 

Once all the forms of ice intelligence came together, a clear picture of the 
extent of the continuous pack was available on a day to day basis. Thus it was 
confirmed that the mooring area in the Princess Elizabeth Trough was free of 
ice, and that an easterly track (at-62°S) from the southern end of the section 
across the Enderby Abyssal Plain was feasible. 

Unfortunately, none of these sources of ice intelligence are at present 
capable of identifying concentrations of smaller icebergs (of length < 10 km). 
For future cruises it may be worth contacting the Antarctic agencies of South 
Africa and Australia in advance of departure. Both countries regularly run 
supply ships to research bases in the area, and an Australian Antarctic 
station, Casey, operates a High Resolution Picture Transmission (HRPT) 
satellite receiver, which could provide further valuable information. 


Multimet
(P.D. Cotton/JRC)

The meteorological monitoring system operated on RRS DISCOVERY is a system 
jointly developed by the British Antarctic Survey and the Instrument and 
Sensors Group at Research Vessel Services (RVS), and was installed prior to 
the 1992-93 series of Southern Ocean cruises. 

The multimet sensors operated during cruise 200 were identical to those of 
DISCOVERY 199, with the exception of the two psychrometers which had been 
replaced in Cape Town at the end of that cruise. The routine sensors comprise 
a wind vane and anemometer, two psychrometers, two photosynthetically active 
radiation (PAR) sensors, two total irradiance sensors, a long-wave 
pyrgeometer, a hull mounted sea-surface temperature sensor and an aneroid 
barometer. In addition to these routine sensors, a sonic anemometer and ship-
born wave recorder were operated. A backup tape device for data from the sonic 
anemometer was installed at the beginning of the cruise, but due to problems 
with new software, tape backups of these data were only possible after day 
051. 

Logging of multimet data started shortly after departure from Cape Town (1311 
day 37) and continued until day 77. The track of cruise 200 traversed a large 
latitude range and so the environmental variables exhibited sizeable 
variations; air temperatures ranging from -2.8°C to 21°C, sea temperatures 
from -0.9°C to 21°C, and wind speeds peaking at over 24 ms-1. It is worth 
noting that the calibration of the sea-surface temperature sensor is only 
valid between +50°C and +25°C, so measurements outside this range should be 
recalibrated with data from another sensor (ADCP). 

Processing of the data was carried out on a daily basis, using a series of 
Unix shell scripts, and daily summary plots thus produced were analyzed to 
check sensor behaviour. Most sensors behaved well, though the port wet bulb 
sensor became noisy toward the end of the cruise. The only significant 
maintenance required was the replacement of the protective 'top hat' on the 
starboard psychrometer, after the original had blown away in strong winds. 


Ashtech GPS data
(W.J. Gould/IOSDL)

An Ashtech Mk XH GPPS 3-D GPS receiver was used to produce accurate ships 
heading (and pitch and roll) data for later elimination of ship gyro errors 
for ADCP calibration. This cruise used the ship's number 2 gyro. 

Two of the receiving antennae were mounted on the rails of the boat deck and 
the remaining two on the wheelhouse top. These were connected to the receiver 
unit in the wheelhouse. 

The data were recorded throughout the cruise at 5 second intervals. At this 
rate the data buffer in the receiver filled in approximately 1 day. The data 
were typically then downloaded (to an IBM PC) twice per day (usually shortly 
after 0600 and 1800z). These files were then transferred to the Pstar system 
using software developed on DISCOVERY 198 and 199. 

The processing path was also via executives developed prior to the cruise. 
Only the sd files containing attitude data were processed, the others were 
archived for possible future analysis. 

The executives used were :

Ash1	  - Requires as input Ashtech file name e.g. sd2OOk93.072 and number for 
	    Pstar file name e.g. att2OOXX
	  - Inputs data to Pstar
	  - Converts time from GPS week and seconds to seconds since start of year
	  - Note when a new GPS week started (00OOz Sunday) data files had to be 
	    adjusted by using finctd. to remove time base jump

ash2	  - Requires as input the number of Pstar file
	  - Performs basic quality checks
	  - Removes data outside sensible ranges

ash3	  - Requires as input the number of Pstar file
	  - Selects data good segments longer than 151 seconds

attexec2  - Requires as input Gyro file number e.g. Gyr2OOX
	  - Also requires time period for plot
	  - Merges Ashtech with Gyro data
	  - Computes heading difference
	  - Plots Gyro heading and heading difference as a function of time.

Finally all data were merged into one file (att200.av) and plotted against 
gyro heading. This gave the data shown in Figure 14*. 

Figure 14*.	Heading errors versus gyro heading

It demonstrates a well defined relationship throughout the cruise between 
heading error and gyro heading. This was over a wide range of speeds, latitude 
and sea state and is encouraging as to the possibility of using such data to 
improve ADCP currents. 

However data collection was far from continuous with often periods of 6 hours 
or more where the processing did not find data that fitted the selection 
criteria for good values. 

The basic receiver performed well and only two problems were noted. On one 
occasion the GPS reception was in general very poor and the Ashtech receiver 
lost lock and then found a position in the northern hemisphere. This was not 
noticed until the following day when no heading information had been received. 
A manual position entry enabled data logging to start. At this stage the 
elevation mask was changed from 10 to 5 degrees and remained so for the rest 
of the cruise. On two occasions, both at night when there was poor lighting on 
the bridge, the wrong data file was accidentally erased. Finally on one 
evening when the data file was being deleted the receiver locked showing the 
message 'Wait for file to delete'. It stayed in this mode until the following 
morning and could only be reset by switching off power to the receiver. Thus a 
data segment was lost. 


RVS logging system
(R.B. Loyd/RVS)

The RVS logging system comprises of 3 distinguishable parts or levels. Each 
level is referred to by one of the following letters A, B or C, and the whole 
system is called the 'ABC' system. 

The Level A consists of a microprocessor based intelligent interface with 
firmware which collects data from a piece of scientific equipment, checks and 
filters it, and outputs it as SMP (ship message protocol) formatted messages. 

There are two versions of dedicated Level As, a MkI based on a 8085 processor 
using CEXEC as the operating system, and a MkII based on a 68000 processor 
running OS9 as the operating system. In addition there are pseudo Level As 
which are PCs around which a piece of equipment is based, which are also 
capable of generating SMP messages. 

The Level B collects each of the Level A SMP messages and writes them to disk 
and backup cartridge tape. It monitors the frequency of these messages, and 
besides providing a central display for the data messages also warns the 
operator when messages fail to appear. This level B, which is based on a 68030 
processor using OS9 as the operating system, collates the data and outputs it 
to the network. 

The Level C, which is a SUN IPC (4/40), takes this data and parses it into RVS 
datafiles. These datafiles are constructed on a RVS styled database for speed 
of access. 

The following list shows the instrument Level As and the variables which were 
logged by the Level C. The first column shows the name used by the Level A. 
Brackets after the Level A name indicate whether it was a MkI (1), MkII (2) or 
IBM compatible PC (PC), based Level A. The 'ADCP' data was collected directly 
by the Level C through one of its serial ports (ttya). The data was written to 
the datafile named in column 2 with the variable names shown in column 3. 

Level A		Datafile	Variables
BOTTLES(1)	bottles		code
CTD_17T(2)	ctd-17		press temp cond trans alt oxyc oxyt temp2 
				cond2 deltat nframes
GPS_TRIM(2)	gps_trim	lat lon pdop hvel hdg svc s 1 s2 s3 s4 s5
GYRO_RVS(2)	gyro_rvs	heading
LOG_CHF(2)	log_chf		speedfa speedps
METLOGGR(PC)	metloggr	windspd winddir pwettemp pdrytemp swettemp 
				sdrytemp seaternp ppar ptir spar stir lwave baro
MX1107(1)	mx 1107		lat lon slt sln el it ct dist dir sat r status
SIM500(2)	sim.500		uncdepth rpow angfa angps
SURFLOG(PC)	surflog		temp_h temp_m cond
WINCH(PC)	winch		cabltype cablout rate tension btension comp angle
		
The following list shows datafiles which contained data directly collected by 
the Level C. 
		adcp_raw 	rawampl beamno, bindepth
		adcp		bindepth heading temp velew velns velvert 
				velerr ampl good bottomew bottomns depth
		xbt		depth temp

Archiving of RVS datafiles

The length of the cruise and the high volume of data generated by the gps, 
adcp, ctd and winch system necessitated regular archiving of these files. The 
frequency of this archiving was dictated largely by the demand for space on 
the raw data disk. 

Report on individual Level As

CTD

This Level A differs from the normal MkII level A in that the hardware is 
based around a 68030 processor running the OS9 operating system. The software 
which it runs is almost identical to that running in a standard MkII level A. 
With the increase in processing power, the level A is able to read and average 
all 16 frames of CTD data it receives each second. 

Gps_trim

Due to problems with the collection of data on the previous cruise a new set 
of Level A firmware provided by RVS was installed. This proved to successfully 
cure all the outstanding problems; however it also served to illustrate the 
cause of those problems - messages other than position data can cause the 
Level As input buffer to overflow resulting in the error message 'Serial 
overrun'. 

Gyro

The Level A logged the gyro once a second. There were no problems with this 
Level A. 

Log_chf

The log outputs to the level A once every 2 seconds. There were no problems 
with this Level A. 

Metloggr

There were no problems with this instrument although it probably has the same 
software faults as the 'surflog'. 

Mx11O7

No major problems. The Level A had to be reset on two occasions when it 
produced alarm messages of 'loss of fix'. On one occasion the MX1107 decoded 
an incorrect date from a satellite. This was corrected manually and did not 
recur. The data from this Level A was not used and has therefore not been 
checked. 

Sim500

This data was largely good but it is important that checks are made as part of 
routine watchkeeping. On a number of occasions during data editing it was 
noticed that the Simrad had selected an incorrect phase. 

Surflog

In the light of experience on the previous cruise the data acceptance limits 
were widened and no further problems occurred. In both the surface and the met 
loggers there remains a problem with incorrect SMP (ship message protocol) 
messages (less than 0.1 percent) associated with the output of the time field. 

Winch

When the winch monitoring system was started up, it was necessary to check 
that the Level B was receiving data. If data was not being received, the data 
lead connection was removed between the winch monitoring system PC and the 
Level B, and then reconnected. (The connector can be found at the forward end 
of the main lab behind the chart recorder in the wooden box. There are two 
wall 25 pin sockets. The furthest one, i.e. Starboard one, is the correct one. 
Access from the side by the door to the corridor is straightforward.) RVS have 
liaised with the manufacturer of the winch monitoring system and improved 
software will be installed for cruise 201. 

Instruments generating data not through Level As. 

ADCP

The ADCP was logged through /dev/ttya on the Level C. Raw data was also 
logged. There were no problems with the data collection. 

XBT

Each XBT (ascii) datafile was transferred to the Level C from the PC on which 
it was collected by floppy disk. This file was processed by 'proxbt' and 
converted to an RVS datafile. 

Report on Level B

During the cruise the Level B collected over 1 000 000 000 bytes of SMP data. 
This data was backed up to both disk and cartridge tape. 

Report on Level C

The majority of the data processing was performed using the 'pstar' suite of 
programs. The exception to this was the navigation. 

30 second values of good data from the raw gps (global positioning system) 
datafile 'gps_trim' were written to the datafile 'gps'. The ship's speed, 
'log_chf ', and heading, 'gyro-rvs', were averaged every 30 seconds to provide 
'northerly' and 'easterly' vectors of speed in the datafile 'relmov'. These 
were used to generate dead reckoning positions to enable both a check on the 
quality of the gps data to be made and to allow interpolated positions to be 
produced when there was no 'gps' data. 

The CTD data was processed to enable screen plots to be displayed to verify 
the data collection. The calibration values used in the processing were the 
same as those used by the PC CTD display system and were held in the 
calibration file '/rvs/control/cal/D199.ctd.cal'. 

RVS datafiles were converted to PSTAR datafiles using the program 'datapup'. 

Operation

In view of the length of the cruise (6 weeks) and the limited disk space 
available it was necessary to archive data to tape on a regular basis. The 
ctd, ADCP, winch and gps were all archived every 15 to 20 days. As most of the 
processing was performed by the 'Pstar' suite of programs, there was not much 
requirement to do any processing with the ABC system other than navigation and 
whatever else was necessary to ensure that the data was being collected 
correctly. The data was normally read into 'Pstar' format within 24 hours of 
being collected so it was possible to cycle some of the data files quite 
regularly. 

The navigation files were made long enough to hold the complete cruise. This 
included 'relmov', 'gps', 'mx1107', 'bestnav' and 'bestdrf'. Likewise with the 
surface data, 'surflog', the meteorological data, 'metloggr' and the 
echosounder data ' sim500'. 


Simrad EA500 echo sounder
(R.B. Loyd/RVS, P.G. Taylor/RVS)

The Simrad EA500 was used throughout the cruise for routine echo sounding and 
acoustic release tests, the latter also being monitored on the IOS waterfall 
display. The fish transducer was used, which apart from the last couple of 
days gave excellent results. On recovery it was found to have a damaged 
fairing. This was subsequently repaired and gave no further problems. The 
performance of the hull transducer was poor when the ship was pitching, even 
moderately, but improved when the ship was on station or underway with a 
following sea. A Hewlett Packard ink jet printer was used to provide real time 
hard copy output. 


Bathymetry data processing

PES data is logged from the Simrad 500EA echo sounder by the RVS Level ABC 
system at the same rate as the 'ping'. This data is subsampled at the 
navigation interval of 30sec. The RVS data editor is used to set the data 
status to 'suspect' when spikes or inconsistent data is detected. Largely the 
raw data has been of a very high quality with only two brief periods when the 
Simrad locked on to echoes in the wrong phase. Once edited the uncorrected 
depths were processed by the program 'prodep' to derive corrected depths using 
Carter's Tables. 


PEXEC and PSTAR
(M.J. Griffiths/JRC)

PEXEC is the name given to a suite of programs developed by staff at the 
Institute of Oceanographic Sciences (IOS) to process hydrographic data, both 
at sea and in the lab. The range of programs covers all aspects of data 
processing, including calibration of data, arithmetic operations, derivation 
of oceanographic parameters and graphical display of data. All graphics are 
produced using the Uniras graphics library. At sea, routine calibration and 
processing is carried out using Unix C-shell scripts which execute a sequence 
of programs. The programs operate on data in a format called PSTAR. The first 
block of each PSTAR data file is a header which gives details of variables 
stored, limits and where the data was collected. All PSTAR headers also 
contain a dataname and version. Logsheets are maintained to record each 
operation, making it possible to identify the processing that has been carried 
out on each file. Remaining blocks in the data file contain the data, stored 
in binary format. 

Backups and archiving

The pstar and archive directories were backed up each alternate night to 
2Gbyte Exabyte tapes, using Unix 'tar' command. A 'rolling' style backup 
regime with five tapes was used. 

All raw and processed data (including non-PSTAR data from Ashtech and MacSat) 
was archived to Sony erasable magneto-optical discs (mounted as standard unix 
file systems). Additionally, PSTAR data was archived to Quarter Inch Cartridge 
(QIC) tape using unix 'dd' command. At the end of the cruise, GF3 copies of 
fully calibrated data for CTD, ADCP, GPS, TSG and XBT were created and written 
to Exabyte tape. 

Users employed a Unix script, developed on this cruise, to copy files to the 
archive area. This script updated a text database of all archived data; each 
entry in the database contained details of the directory, optical disk and (if 
applicable) the QIC tape number that the file has been archived to. This 
prevented duplicates of data being archived, and gave speedy retrieval of 
offline data. 

Navigation

One minute values from Bestnav were read in from RVS level C each 24 hours, 
and converted to PSTAR. These 24 hour files are appended to form one 
navigation file. Distance along track was maintained, and the eastward and 
northward velocities were calculated from the position data. The velocity data 
were median despiked, discarding data more than 40 crrx/s from a mean computed 
over 5 adjacent data values. Subsequent gaps were filled using linear 
interpolation. Finally, the velocity data were smoothed using a top hat filter 
applied over 11 data cycles, to produce a master navigation file. 

Global Positioning System (GPS)

One hertz GPS data from the Trimble was logged on the RVS level C, and 
converted to PSTAR each 24 hours. No processing was carried out on the data. 
In general, GPS data coverage for the cruise was no more than adequate. For 
the entire cruise, there were over 20 periods when no GPS data were received 
for ten minutes or more. From day 58 to 59, coverage was particularly bad, 
with only 20 hours of data collected. In general, 2 to 3 hours of data were 
poor quality, with pdop greater than 5. 

Ship's Gyro

Data from the ship's Number 2 gyro were collected each 24 hours at a rate of 1 
hz. Heading data out of the range 0-360 degrees was discarded, but no other 
processing was carried out. The daily files were appended to a master file, 
used for processing the Ashtech GPS data. 

Magnavox 1107

Data from the Magnavox were collected during the cruise and read into PSTAR 
format. No processing was carried out on these data. 

Data Processing

All hardware remained the same as the previous cruise (D199); see below: 

(compiled by VCC on D199)

Personal Computers

3 Apple Macintosh Classics	(40 Mb Hard Disc, 4 Mb RAM)
1 Apple Macintosh ClassicII 	(40 Mb Hard Disc, 4 Mb RAM)
1 Apple Macintosh II si (80 Mb Hard Disc, 5 Mb RAM) - This was connected to a 
Dartcom System II satellite image receiver. 
Sun Workstations

NodeName	Type	 RAM (Mb)	Hard Disc (Mb)	Main Use		Peripherals
discovery1	IPC	    12		2x327		Final data logging	Exabyte drive
					lx207		QIC 150 tape	
					
discovery2	IPC	    12		lx207		Data processing		Magneto/
					lx1200		Data storage/		Optical drive
							Archiving		QIC 150 drive
					Partition Size	Name	
					227489		/pstar	
					872735		/pstar/data	
					182143		/archive	
					
discovery3	Sparc	    8		2x327		Data processing	
		Station 1				
							Partition Size		Name
							299621			/packages
							299621			/pstar/work
					
discovery4	Sparc	    8		2x327		Data processing	
		Station 1				
							Partition Size		Name
							299118			/pstar/spare

Output devices

Apple LaserWriter II (Mono Laser Printer) 
Hewlett Packard Paintjet XL (InkJet Colour Plotter) 
Tektronix 4693RGB (Thermal transfer plotter) 
Hewlett Packard LaserJet III (Mono Laser Printer) 
NEC Pinwriter P5 (Dot Matrix line printer) 
Bruning Drum-type Pen Plotter. 
Networking

All PCs, workstations and a number of output devices were connected to a thin 
Ethernet (1013ase2) local area network. The Sun workstations have integral 
Ethernet interfaces, the Apple Macintoshes were connected via external SCSI 
Ethernet interfaces. 


RVS Engineering Division
(P.J. Mason/RVS, C. Day/RVS)

Z7

This is a brief report on the equipment used during DISCOVERY 200 that falls 
under the RVS Engineering Division's responsibility. 

Ship's winch system

The winch system functioned well for the duration of the cruise. 

The winch was used predominantly for the deployment of the large IOS CTD 
package. Care had to be taken for the first few meters of deployment of the 
CTD in rough seas due to the package kiting in the swell, which on one 
occasion caused the warp to go slack, resulting in a large snatch loading. 

The size of the package, the depth of deployment and frequently the sea state, 
resulted in some of the deployments being very close to and occasionally 
exceeding the maximum limits for the cable being used. 

Gantries

The starboard gantry was used for launching tide gauges and deploying the CTD 
package. The gantry proved very effective and safe for handling the packages 
even in bad weather conditions. It operated well for the duration of the 
cruise with the exception of one occasion when a fuse in the 24V power supply 
failed. The gantry was operated manually for the associated deployment and was 
fixed prior to recovery. 

The aft gantry and Rexroth winch were used for the deployment of the buoyancy 
for the current meter moorings. The gantry operated without any problems. 

Cranes

The port aft crane was out of order due to one of the hydraulic rams being 
badly scored. This problem resulted in the deployment of the current meter 
moorings being centred around the starboard aft crane. 

The starboard aft crane was the only one used during this cruise. It was used 
as part of the set-up for mooring deployments and functioned well for the 
duration of the cruise. The use of this crane to place chain clumps over the 
stern was tricky and required a very competent operator. 

Double barrel winch

The double barrel winch was used for the deployment of the moorings. It 
operated well for the duration of the cruise provided the oil was kept warm in 
the very cold conditions to prevent the motor starting current from tripping 
the breakers. 

Non toxic supply

The non toxic supply was continuously in use for the whole of the cruise and 
performed well. 


Table 1. ADOX CTD Station list


Station	Date/Day	Time	Lat (S)		Lon (E)		Depth	Wire	Ht	Levels	   comments
No			(z)					(m)	out	Off	sampled
			0915	40   10.5	17   59.2					
12338	08-II(39)	1113	40   10.6	17   59.4	4931	4818	99	13/14	
 			1353	40   09.8	17   59.6					
			1109	52   00.0	17   30.1					
12339	11-II(42)	1159	52   00.1	17   30.2	2586	568	85	16/18	
 			1318	52   00.2	17   30.1					
			0906	54   30.0	19   20.1					
12340	12-II(43)	1035	54   30.0	19   21.0	3841	3777	21	15/18	
 			1205	54   29.8	19   21.7					
			0550	56   09.9	20   59.8					   Station aborted 
												   due to iceberg
												   No samples
12341	13-II(44)	0623	56   09.8	20   59.9	3896	1127	0		
 			0644	56   09.8	21   00.0					
			0740	56   15.8	21   07.5					
12342	13-II(44)	0911	56   15.6	21   07.6	4580	4523	23	19/19	   Replacement for 12341
 			1118	56   15.3	21   08.0					
			0419	58   02.7	23   04.3					
12343	14-II(45)	0604	58   02.1	23   04.5	5153	5077	27	19/19	
 			0845	58   02.1	23   03.6					
			1817	59   40.5	24   55.1					
12344	14-II(45)	1957	59   40.8	24   53.8	5294	5150	106	19/20	
 			2152	59   41.0	24   52.3					
			0413	62   26.0	28   41.3					
12345	16-II(47)	0549	62   26.3	28   42.6	5213	5155	17	18/20	
 			0747	62   26.3	28   44.2					
			0237	64   28.4	32   26.9					   Multisampler stuck at 
												   3000m.
												   Continued as 12347
12346	17-II(48)	0400	64   28.3	32   26.8	4732	4655	23	8/8	
 			0557	64   28.5	32   27.0					
			0725	64   28.7	32   27.0					
12347	17-II(48)	0818	64   28.7	32   26.7	4728	2750		10/10	
 			0914	64   28A	32   26.8					
			0630	64   40.1	58   09.8					
12348	20-II(51)	0747	64   40.5	58   09.9	4009	3946	18	18/21	
 			0943	64   40.8	58   10.6					
			0805	62   09.9	83   16.9					
12349	23-II(54)	0905	62   10.2	83   16.2	2706	2643	18	18/18	
 			1017	62   10.2	83   15.5					
			1327	62   44.9	83   28.7					
12350	23-II(54)	1418	62   44.8	83   28.2	2507	2435	20	18/18	
 			1549	62   44.9	83   28.3					
			2305	63   21.3	83   54.					
12351	24-II(55)	0014	63   21.3	83   55.5	2897	2814	20	19/19	
 			0203	63   21.0	83   56.8					
			1431	64   09.9	84   35.2					
12355	24-II(55)	1545	64   10.1	84   34.4	3700	3617	19	19/19	
 			1745	64   10.1	84   34.4					
			2302	64   37.1	85   00.0					
12356	25-II(56)	0002	64   37.1	84   59.9	3619	3530	19	19/20	
 			0230	64   37.5	84   59.3					
			0515	65   05.6	85   19.0					   Shallow cast for trace 
												   metals and DMS
12357	25-II(56)	0528	65   05.6	85   18.9	3114	400	-	14/14	
 			0604	65   05.6	85   18.7					
			0703	65   05.6	85   18.8					
12358	25-II(56)	0810	65   05.5	85   19.2	3104	3027	22	19/19	
 			0932	65   05.5	85   19.4					
			2344	63   42.5	84   09.8					
12361(1)  26-II(57)	0053	63   42.7	84   10.0	3735	3650	17	13/14	
 			0220	63   43.0	84   09.6					
			0344	63   43.3	84   08.6					   Completion of station after
												   multisampler failure.
12361(2) 26-II(57)	0357	63   43.4	84   08.5	3732	600	-	7/7	
 			0414	63   43.3	84   08.3					
			1346	52   55.6	72   06.1					   CFC calibration all bottles 
												   at 1000m
12362	1-111(60)	1413	52   55.5	72   06.4	1416	1000	-	1/1	
 			1450	52   55.4	72   06.4					
			1529	48   28.4	60   57.8					
12364	4-III(63)	1706	48   28.5	60   57.9	4206	4140	19	18/21	
 			1921	48   28.8	60   58.0					
			1410	48   16.4	60   01.5					
12368	5-III(64)	1556	48   16.3	60   01.0	4485	4426	19	16/20	
 			1803	48   16.5	60   00.9					
			2244	48   05.4	59   09.1					
12369	6-III(65)	0029	48   05.1	59   09.8	4466	4413	18	16/21	
 			0227	48   04.8	59   09.8					
			1732	47   52.5	58   12.9					
12372	6-III(65)	1918	47   52.4	58   13.7	4309	4254	18	20/20	
 			2057	47   52.5	58   14.3					
			0045	47   40.4	57   18.9					
12373	7-III(66)	0212	47   40.3	57   18.0	4170	4137	12	21/21	
 			0405	47   40.8	57   17.8					
			1828	47   17.5	55   17.3					
12376	8-III(67)	2002	47   17.5	55   17.4	3996	3935	19	19/19	
 			2130	47   17.8	55   17.5					
			1902	46   55.1	53   37.9					
12380	9-III(68)	2023	46   54.8	53   38.0	3720	3653	18	20/20	
 			2140	46   54.3	53   38.3					
			0124	47   07.7	54   33.8					
12381	10-III(69)	0305	47   07.8	54   33.5	3922	3880	17	19/19	
 			0435	47   08.7	54   33.6					
			1333	46   47.0	53   06.7					
12383	10-III(69)	1436	46   46.5	53   07.1	2905	2856	21	19/19	
 			1540	46   46.5	53   07.2					
												   Start delayed due to
			1442	45   24.1	47   58.4					   gantry failure Fault
12385	11-III(70)	1602	45   24.0	47   57.9	3082	3013	21	19/20	   on alt connector, noisy 
			1715	45   24.1	47   57A					   data. Top 11 bottles
												   sampled for trace metals

			0842	40   27.9	33   45.5					   Shallow dip for trace 
												   metals
12386	14-III(73)	0854	40   27.9	33   45.4	4846	500	-	15/15	
 			0921	40   28.0	33   45.3					


Notes:
Times are:	First		Start down
		Second		At bottom
		Third		On deck

Positions are taken from abnav200I.av at times stated

Depth is depth recorded by Simrad PES (assumed 1500 ms-1 with 17 m added to 
account for sinking of the PES fish on station. Carters Tables corrections 
have not been made 

Wire out is indicated value at bottom of cast

Ht off is height above seabed at closest approach as measured by the altimeter

Levels sampled x/y. x is number of individual levels at which bottles were 
closed, y is the number that should have been sampled if the multisampler had 
behaved perfectly 

Table 2. Bottle flying depths (wire out W)

Bottle	Station Number
Number	12338	12339	12340	12342	12343	12344	12345	12346	12347	12348	12349
1	4818	2586	3777	4523	5077	5150	5155 	4655	50	3946	2643
2	4818	2586	3777	4523	4750	5150	5155 	4655	50	3946	2643
3	4818	2440	3600	4250	4500	4730	4750 	4500	2	3740	2500
4	4818	2440	3600	4000	4250	4500	4500 	4250		3500	2250
5	4500	2200	3400	3700	4000	4250	4250 	4000		3250	2250
6	4000	2200	3200	3400	3500	4000	4250 	4000		3250	2000
7	3500	2000	3200	3000	3500	4000	4000 	3750		3000	1750
8	3500	1800	2500	3000	3000	3500	3500 	3500		2500	1500
9	3500	1800	2500	2750	3000	3000	3000 	3250		2000	1500
10	3500	1800	2200	2500	2500	2000	2500 	3000		1750	1250
11	3000	1400	2000	2000	2000	1500	2000			1500	1000
12	2000	1200	1800	1500	1500	1000	2000			1113	800
13	2000	1200	1500	1500	1000	1000	1500			800	800
14	1500	900	1500	1000	800	948	1500		2750	800	600
15	1500	900	1200	800	800	860	1250		2750	450	400
16	1250	800	1200	600	600	700	1000		2500	450	300
17	1250	700	700	600	400	500	750		2000	150	200
18	1250	600	500	400	400	300	500		1500	150	150
19	1250	500	300	300	300	200	200		1000	100	99
20	1250	400	101	200	200	100	100		1000	100	75
21	1000	300	101	100	100	50	50		750	70	75
22	800	150	20	50	50	10	1		500	50	10
23	600	150		20	10				250	30	2
24	400	10							250	2	2
											

Bottle 	Station Number
Number	12350	12351	12355	12356	12357	12358	12361	12362	12364	12368	12369
1	2435	2814	3617	3530	400	3027	3650	1000	4140	4426	4413
2	2435	2814	3617	3530	400	3027	3650	1000	4140	4426	4413
3	2250	2750	3400	3400	300	2900	3500	1000	3750	4250	4245
4	2000	2600	3200	3200	250	2700	3250	1000	3750	4250	4245
5	2000	2600	3200	3200	200	2700	3250	1000	3500	4000	4000
6	1750	2400	3000	3000	200	2500	3000	1000	3250	3749	3750
7	1500	2200	2750	2750	150	2200	2750	1000	3000	3200	3500
8	1250	2000	2500	2500	150	2200	2500	1000	2500	3200	3500
9	1250	2000	2500	2500	100	2000	2500	1000	2500	2799	3250
10	1000	1750	2250	2250	100	1741	2250	1000	2250	2500	2750
11	800	1500	2000	2000	75	1500	2000	1000	2250	2500	2750
12	800	1250	1600	1750	75	1250	1750	1000	2000	2100	2250
13	600	1250	1600	1500	50	1250	1500	1000	1750	2100	2250
14	500	1000	1200	1250	50	1000	1250	1000	1500	1400	1750
15	400	800	900	1000	35	800	1000	1000	1250	1000	1750
16	300	600	700	600	31	600	600	1000	800	750	1250
17	200	400	500	600	31	400	600	1000	800	750	1250
18	150	300	300	400	26	300	600	1000	600	350	750
19	74	200	200	300	26	174	400	1000	400	350	750
20	74	100	150	200	20	99	300	1000	400	200	500
21	50	70	52	64	20	50	200	1000	300	100	300
22	10	70	30	64	15	15	150	1000	200	50	200
23	10	10	10	10	15	15	70	1000	100	50	100
24	3	2	10	2	0	0	10	1000	20	10	10
Table 2. (continued)
Bottle 
Number	Station Number
	12372	12373	12376	12380	12381	12383	12385	12386
1	4254	4137	3935	3653	3880	2856	3013	500
2	4254	4137	3935	3653	3880	2856	3013	500
3	4100	4050	3750	3500	3750	2750	2900	450
4	3800	3800	3750	3500	3500	2600	2800	400
5	3800	3500	3500	3250	3500	2600	2800	400
6	3500	3250	3250	3000	3250	2400	2600	350
7	3250	3000	3000	2750	3000	2200	2400	300
8	3000	2750	2750	2500	2750	2000	2200	300
9	3000	2750	2750	2250	2750	2000	2200	250
10	2750	2500	2500	2000	2500	1800	2000	250
11	2500	2250	2249	1750	2250	1600	1800	200
12	2250	2000	2000	1500	2000	1400	1400	200
13	2250	1750	2000	1500	2000	1400	550	150
14	2000	1500	1750	1250	1750	1200	400	125
15	1750	1250	1500	1000	1500	1000	300	100
16	1500	1000	1250	800	1250	800	225	100
17	1250	800	1000	600	1000	600	150	75
18	1000	600	800	400	800	400	75	75
19	800	400	600	300	600	300	50	59
20	600	200	400	200	400	200	40	40
21	400	100	200	100	200	150	40	25
22	200	50	50	50	50	50	25	25
23	50	50	50	50	50	50	10	10
24	10	10	10	10	20	10	10	

Table 3. Current meter mooring details							

Mooring		9301		9302		9303		9304		9305		9306		9307		9308		9309		9310		9311		9312		9313		9314		9315		9316		9317		9318
		 K		 L		 M		 0		 N		 J		BPR		 I		 H		 G		 F		 E		 D		 C		 B		BPR		 A		 P
Depth (m)	2636		3048		3700		3367		3654		3565		3610		4356		4393		4478		4240		4427		4141		3996		3809		3617		3345		3057
DATE		24/2/93		24/2/93		24/2/93		25/2/93		25/2/93		4/3/93		4/3/93		5/3/93		5/3193		6/3/93		6/3/93		7/3/93		8/3/93		9/3/93		9/3/93		9/3/93		10/3/93		11/3/93
DAY		55		55		55		56		56		63		63		64		64		65		65		66		67		68		68		68		69		70
TIME Z		0449		0854		1238		1236		1552		1210		2135		0631		1225		0733		1547		0933		1532		0616		1224		1704		1202		1345
DOWN Z																2236								1619		1006		1601		0646		1249		1804		1225
POSN S		63-03.20	63-29.928	63-56.064	64-49.232	64-22.787	48 34.75			48-22.686	48 11.98			47 45.28							47.02						45 26.166
POSN E		83-35.76	83-56.608	84-18.582	85-07.713	84-41.131	61 30-76			60-29.724	59 37.68			58.02.79							54.0882						47 59.640
BESTNAV S	63 03.21	63 29.82	63 56.01	64 49.23	64 22.65	48 34.77	48 35.03	48 22.69	48 11.91	48 0013		47 45.28	47 36.95	47 24.96	47 06.31	47 01.24	46 52.26	46 50.52	45 26.23
BESTNAV E	83 35.41	83 57.19	84 19.12	85 07.82	94 41.64	61 30.77	61 27.96	60 29.74	59 37.65	58 38.16	58 02.80	56 48.36	55 36.55	55 06.48	54 05.31	53 28.31	53 20.27	47 59.67
METER																						10856				
Ht. (m)																						3915			
METER																						10862						10855	
Ht. (m)																						3614						3600				
METER																						9967						10854	
Ht. (m)																						2895						3299				
METER																						9968						10113	
Ht. (m)																						2167						2580				
METER																		155				238		178		555		9969		553			
Ht. (m)																		2738				2064		2680		1847		1849		1630			
METER				124		002				490						397		696		855		652		607		606		611		523				213	
Ht. (m)				844		724				962						1956		1570		2413		1378		1627		1102		1239		1102				1681	
METER		037		373		046		526		879		801				743		109		644		331		703		278		234		442				825		128
Ht. (m)		533		316		305		577		431		1675				1053		763		573		562		574		574		590		574				581		781
METER		476		898		073		768		924		933				980		981		965		942		638		546		436		279				146		192
Ht. (m)		46		46		46		46		46		46				46		46		46		46		46		46		46		46				46		46
BEACON														160.725																		160.725		
A/R #1		72		94		69		95		93		96		47124		71		267		2187		2345		2180		2184		2348		2333		46421		2344		76
PING ON		0644		4624		0524		2624		2584		4644				0624		320		320		320		320		320		318		320				318		2564
OFF/PER		0633		4613		0513		2613		2573		4633		RX11.5		0613		0.94		1.08		1.06		1.14		1.02		1.18		0.94		RX14.0		0.96		2553
WINDOW		0631		4611		0511		2611		2571		4631		TX12.0		0611																TX12.0				2551
RELEASE		0646		4626		0526		2626		2586		4646		CDE D		0626		299		338		280		240		400		418		442		CDE D		440		2566
A/R #2														2517								2402				2400		2401		2347		2518				
PINGER														322								319				319		321		320		322				
RELEASE														262								362				339		441		240		279				
PERIOD														1.18								0.98				0.94		0.96		1.02		1.16				


Table 4. XBT Drop List

Drop			Time						TSG	XBT
No.	Date (Day)	(z)	Lat (S)		Long (E)	Probe	Temp	Surface T.	Comments
I	06-Il (37)	2355	35 01.60	17 59.57	T7	20.5	20.84	
2	07-II (38)	0415	35 43.07	18 00.73	T7	20.2	20.89	
3	07-II (38)	1045	36 40.08	17 59.17	T7	19.8	19.77	
4	07-II (38)	1644	37 27.36	18 01.56	T7	20.7	20.48	
5	07-II (38)	1957	38 00.96	18 01.50	T7	20.7	20.45	
6	07-II (38)	2358	38 44.47	17 53.95	T7	23.2	23.51	
7	08-II (39)	0400	39 29.15	17 55.81	T7	20.8	20.72	
8	08-Il (39)	1635	40 23.18	18 01.53	T7	20.5	20.91	
9	08-II (39)	20(9	40 59.75	18 06.40	T7	20.4	20.70	
10	08-Il (39)	2358	41 39.53	18 01.16	17	18.2	18.63	
11	09-II (40)	0411	42 28.82	17 58.50	T7	16.4	15.78	
12	09-II (40)	0804	43 15.62	18 00.66	T7	10.2	10.02	
13	09-II (40)	1157	43 59.40	17 59.87	T7	11.6	12.02	
14	09-Il (40)	1630	44 54.41	17 55.74	T7	9.9	9.86	
15	10-II (41)	0517	47 39.42	17 52.52	T7	7.4	7.06	
16	10-II (41)	0811	47 39.20	17 54.30	T7	6.2		Wire. broke at approximately 40m
17	10-II (41)	0806	47 39.42	17 54.35	T7	6.0	5.88	
18	10-II (41)	1153	48 21.16	17 52.55	T7	4.7	4.87	
19	10-II (41)	1639	49 11.75	17 43.21	T7	4.3		Wire broke at approximately 50m
20	10-II (41)	1653	49 14.34	17 43.08	T7	4.3	4.90	
21	10-Il (41)	2020	49 45.92	17 51.97	T7	3.5	3.45	
22	10-Il (41)	2353	50 13.59	17 49.00	T7	3.4	3.49	
23	11-II (42)	0400	50 39.90	17 42.89	T7	3.4	3.35	
24	11-II (42)	0758	51 23.92	18 30.80	T7	2.5	3.32	
25	11-Il (42)	1637	52 19.15	17 43.77	T7	2.1	2.01	
26	11-II (42)	2028	52 54.97	18 09.50	T7	1.5	1.66	
27	11-Il (42)	2356	53 09.77	18 22.50	T7	1.3	1.62	
28	12-II (43)	0416	53 39.47	18 39.81	T7	1.5	1.53	
29	12-II (43)	1633	54 54.78	19 49.33	T7	1.6	1.69	
30	13-II (44)	0414	55 54.84	20 45.44	T7	1.5	1.51	
31	13-II (44)	1609	56 39.00	21 29.14	T7	1.5	1.56	
32	13-II (44)	2012	57 18.31	22 16.07	T7	1.6	1.62	
33	13-II (44)	2355	57 35.35	22 35.54	T7	1.6	1.76	
34	14-II (45)	1153	58 33.82	23 37.45	T7	1.6	1.80	
35	14-II (45)	1655	59 29.35	24 43.71	T7	1.9	1.80	
36	14-Il (45)	0057	59 45.86	24 57.96	T5	1.8	1.95	
37	15-II (46)	0412	60 11.55	25 33.20	T7	1.6	1.62	
38	15-Il (46)	0802	60 52.57	26 24.82	T7	1.6	1.61	
39	15-II (46)	1142	61 30.03	27 17.72	T7	1.3	1.42	
40	15-Il (46)	1538	61 52.66	27 54.08	T7	1.2	1.28	
41	15-II (46)	2033	62 09.50	2819.50		T7	1.2		Drop aborted - no trace on screen
42	15-II (46)	2048	62 10.55	28 20.74	T7	1.2	1.22	
43	16-II (47)	1150	63 02.36	29 47.91	T7	1.5	1.58	
44	16-II (47)	1549	63 40.86	30 58.74	T7	1.4	1.34	
45	16-Il (47)	2013	64 07.57	31 53.82	T7	1.3	1.36	
46	16-II (47)	2350	64 19.46	32 15.81	T7	1.1	1.18	
47	17-II (48)	1152	64 24A9		33 40.24	T7	1.2	1.30	
48	17-II (48)	1556	64 19.54	35 37.24	T7	1.3	1.32	
49	17-II (48)	1959	64 17.57	37 15.31	T7	1.5	1.32	
50	17-Il (48)	2358	64 14.26	38 03.49	T7	1.3	1.36	Wire stretch at approximately 75m
51	18-Il (49)	0410	64 09.67	39 45.62	T7	1.4	1.46	
52	18-Il (49)	0742	64 05.74	41 25.81	T7	1.3	1.36	
53	18-II (49)	1152	64 01.55	42 43.20	T7	1.2	1.28	
54	18-II (49)	1556	63 56.95	44 27.77	T7	1.2	1.00	
55	18-II (49)	2012	63 53.56	45 37.80	T7	0.8	0.75	
56	18-II (49)	2354	63 50.88	46 14.72	T7	0.8	0.82	Wire stretch
57	19-II (50)	0409	63 47.76	47 57.85	T7	1.1	1.11	
58	19-II (50)	0815	63 44.23	49 53.77	T7	1.0	1.01	Wire stretch
59	19-II (50)	1155	63 37.38	51 36.62	T7	0.7		Wire stretch
19-	11 (50)		1158					T7			Wire stretch
60	19-II (50)	1208	63 37.11	51 42.75	T7	0.7	0.67	Wire stretch at approximately 160m
61	19-Il (50)	1548	63 41.74	53 23.33	T7	0.4	0.43	
62	19-II (50)	2348	64 04.32	55 21.42	T7	0.4	0.43	
63	20-II (51)	0407	64 28.10	57 11.95	T7	0.3	0.38	Wire stretch at approximately 90m
64	20-II (51)	1146	64 34.70	59 05.90	T7	0.2	0.25	
65	20-II (51)	1538	64 24.17	60 57.83	T7	0.5	0.40	
66	20-II (51)	2037	64 20.84	62 16.54	T7	0.6	0.64	
67	21-II (52)	0400	64 06A2		64 55.71	T7	0.6	0.58	
68	21-II (52)	1149	63 40.72	68 29.76	T7	0.9	0.88	
69	21-II (52)	1551	63 30.91	70 22.51	T7	1.0	0.97	
70	21-Il (52)	2005	63 26.30	71 26.72	T7	1.1	1.05	
71	21-II (52)	2355	63 21.80	72 08.51	T7	1.0	1.05	Wire stretch at 460m
	22-II (53)	0354					T7			No trace on screen
	22-II (53)	0416					T7			No trace on screen
72	22-II (53)	0714	63 06AI		74 37.60	T7	1.1	1.19	
73	22-Il (53)	1151	62 56.24	76 18.71	T7	1.2	1.20	
74	22-II (53)	1804	62 42.19	78 22.86	T7	1.4	1.47	
75	22-II (53)	2355	62 34.32	79 51.66	T7	1.2	1.21	
76	22-Il (53)	0359	62 19.86	81 34.92	T7	1.4	1.38	
77	26-Il (57)	0917	62 50.60	83 09.72	T7	1.0	0.90	
78	26-II (57)	1152	62 23.47	82 38.31	T7	1.2	1.19	
79	26-II (57)	2002	61 26.48	81 34.03	T5	1.3	1.36	
80	27-II (58)	0000					T7	1.2		Wire stretch
81	27-II (58)	0010	61 00.52	81 03A7		T7	1.2	1.32	GOES transmitter failed
82	27-II (58)	0402	60 20.29	80 12.07	T7		1.5	Profile not saved by SEAS unit
83	27-Il (58)	0818	59 34.56	79 21.40	T7	1.1	1.07	
84	27-II (58)	1311	58 43.02	78 28.88	T7	1.6	1.61	
85	27-II (58)	1623	58 17.56	78 04.34	T5	1.6	1.63	Probe hit seafloor before finished
86	27-II (58)	2013	57 59.73	77 46.97	T7	1.7	1.72	
87	27-Il (58)	2353	57 42.42	77 28.57	T7	1.9	1.88	
88	28-II (59)	0422	57 04.16	76 46.61	T7	1.7	1.69	
89	28-II (59)	0813	56 29.08	76 09.53	T7	1.8	1.65	
90	28-II (59)	1150	55 56.40	75 36.91	T7	2.0	2.06	
91	28-II (59)	1708	5518.03		75 03.86	T5	2.9	2.89	
92	28-Il (59)	2015	55 04.38	74 55.59	T7	2.8	2.84	
93	28-II (59)	2352	54 47.07	74 40.86	T7	2.6	2.55	Wire broke
94	28-II (59)	2355	54 46.60	74 40.31	T7	2.6	2.63	
95	01-III (60)	0403	54 08.31	73 54.54	T7	3.0	3.07	
	01-III (60)	0812					T7	3.4		No trace on screen
96	01-III (60)	0817	53 23.21	73 18.20	T7	3.4	3.43	
97	01-Ill (60)	1750	52 45.29	71 48.81	T7	3.6	3.58	
98	01-III (60)	2013	52 38.55	71 34.06	77	3.6	3.59	
	01-III (60)	2354					T7	3.6		Wire stretched and broke
99	01-Ill (60)	2358	52 29.97	71 08A6		77	3.6	3.60	
100	02-III (61)	0410	52 10.74	70 10.31	17	3.8	3.82	
101	02-III (61)	0800	51 54.21	69 27.72	T7	3.8	3.80	Wire stretch at approximately 130m
102	02-III (61)	1152	51 32.34	68 43.71	T7	3.9	3.96	Wire stretch at approximately 30m
103	02-III (61)	1155	51 32.64	68 43.12	T7	3.9	3.92	then broken
104	02-III (61)	1654	51 11.50	67 47.39	T5	4.1	4.11	
105	02-III (61)	2007	51 02.58	67 30.28	T7	4.2	4.19	
106	02-III (61)	2350	50 52.20	67 08A3		T7	4.1	4.11	
107	03-III (62)	0414	50 32AO		66 14.03	T7	4.3	4.20	
108	03-Ill (62)	0801	50 13.92	65 22.58	T7	4.9		Profile completely spurious (35C)
109	03-III (62)	0812	50 13.04	65 20.07	T7	4.9	4.87	
110	03-III (62)	1148	49 54.95	64 31.57	T7	4.9	4.82	
III	03-Ill (62)	1523	49 33.65	63 41.97	T7	5.0	5.91	
112	03-III (62)	2011	49 09.57	62 40.72	T7	5A	5.50	Wind 40 knots. Wire across deck
113	10-Ill (69)	1858	46 43.11	52 16.80	T7	6.4	6.44	
114	11-III (70)	0003	46 37.56	50 49.53	T7	7.0	6.98	
115	11-III (70)	0340	46 26.99	50 04.81	T7	7.1	7.12	
116	11-Ill (70)	0805	46 00.12	49 07.51	T7	8.1	8.10	
117	11-III (70)	2013	45 09.86	47 15.29	T7	7.8	7.72	
118	11-III (70)	2356	44 50.75	46 19.49	T7	8.9	8.99	
119	12-III (71)	0403	44 30.68	45 17.13	T7	7.2	9.07	
120	12-III (71)	0805	44 15.93	44 22.72	T7	9.6	9.64	
121	12-III (71)	1155	44 01.74	43 38.77	T7	10.4	10.44	
122	12-III (71)	1633	43 40.04	42 50.31	T7	9.5	9.48	
123	12-III (71)	2001	43 18.21	42 06.28	T7	10.4		Spurious profile
124	12-Ill (71)	2008	43 17.61	42 04.60	T7	10.4	10.23	
125	12-III (71)	2352	43 01.54	41 11.72	T7	12.4	12.45	
126	13-III (72)	0408	42 44.55	40 10.28	T7	13.9	13.89	
127	13-III (72)	0805	42 27.56	39 18.77	T7	14.1	14.28	
	13-III (72)	1152					T7	16.3		Wire broke at approximately 250m
128	13-III (72)	1158	42 10.96	38 34.24	T7	16.3	16.34	
129	13-III (72)	1554	41 49.34	37 45.17	T7	15.0	15.04	
130	13-III (72)	2008	41 24.78	36 49.76	T7	14.6	14.60	Wire broke at approximately 650m
	13-III (72)	2340					T7	14.7		No trace on screen
	13-III (72)	2340					T7	14.7		No trace on screen
131	14-III (73)	0415	40 45.23	34 50.90	T7	16.4	16.38	T4 selected 
											on menu => 450m depth
132	14-III (73)	0419	40 44.93	34 49.87	T7	16.4	16.37	
133	14-III (73)	1149	40 29.07	33 07.88	T7	18.3	18.38	
134	14-III (73)	1549	40 35.81	32 17.32	T7	18.6	18.00	
135	14-III (73)	2008	40 11.92	31 23.10	T7	20.9	20.59	
136	14-III (73)	2354	39 51.12	30 39A2		T7	18.5	18.59	
137	15-III (74)	0410	39 31.59	29 46.18	T7	20.5	20.45	Wire stretch 
											at approximately 75m
138	15-III (74)	0758	39 14.98	28 55.65	T7	20.0	19.95	
139	15-III (74)	1153	38 58AI		28 14.76	T7	20.1	20.14	
140	15-III (74)	1649	38 33.03	27 19.85	T7	20.1	20.07	
141	15-III (74)	2000	38 15.58	26 44A8		T7	20.2	20.21	
142	15-III (74)	2351	37 51AI		26 01.27	T7	20.5	20.54	
143	16-III (75)	0420	37 28.54	25 05.26	T7	21.5	21.49	
144	16-III (75)	0810	37 16.77	24 35.65	T5	21.7	21.63	

* All figures shown in PDF file.




WHPO DATA CONSISTENCY CHECK
---------------------------

The WHP-Exchange format bottle and/or CTD data from this cruise have been
examined by a computer application for contents and consistency. The
parameters found for the files are listed, a check is made to see if all
CTD files for this cruise contain the same CTD parameters, a check is made
to see if there is a one-to-one correspondence between bottle station
numbers and CTD station numbers, a check is made to see that pressures
increase through each file for each station, and a check is made to locate
multiple casts for the same station number in the bottle data. Results of
those checks are reported in this '_check.txt' file.

When both bottle and CTD data are available, the CTD salinity data (and, if
available, CTD oxygen data) reported in the bottle data file are subtracted
from the corresponding bottle data and the differences are plotted for the
entire cruise. Those plots are the' _sal.ps' and '_oxy.ps' files.

Following parameters found for bottle file:

                EXPOCODE       |  NITRAT         |  DEPTH
                SECT_ID        |  NITRAT_FLAG_W  |  CTDPRS
                STNNBR         |  PHSPHT         |  CTDTMP
                CASTNO         |  PHSPHT_FLAG_W  |  CTDSAL
                SAMPNO         |  CFC-11         |  CTDSAL_FLAG_W
                BTLNBR         |  CFC-11_FLAG_W  |  SALNTY
                BTLNBR_FLAG_W  |  CFC-12         |  SALNTY_FLAG_W
                DATE           |  CFC-12_FLAG_W  |  CTDOXY
                TIME           |  CFC113         |  CTDOXY_FLAG_W
                LATITUDE       |  CFC113_FLAG_W  |  OXYGEN
                LONGITUDE      |  CCL4           |  OXYGEN_FLAG_W
                CCL4_FLAG_W    |  SILCAT
                O18O16         |  SILCAT_FLAG_W

 All ctd parameters match the parameters in the reference station.
 Station #12346 exists in s04_hy1.csv, but does not have a corresponding CTD 
  file.
 No bottle pressure inversions found.
 Bottle file pressures are increasing.
 No multiple casts found in bottle data.





WHPO Data Processing Notes:
--------------------------

Date      Contact      Data Type       Data Status Summary
--------  -----------  --------------  ----------------------------------------
09/23/98  Diggs        CTD             Submitted for DQE; now online
          The CTD are now on the website and are unencrypted.
          
12/23/98  Muus         SUM             Data Update
          s04.note         19981223WHPOSIODM
          s04_su.txt - I08A in Indian Ocean Table has .SUM file s04su.txt with 
            only one station listed as S4 and the others are I06, I08 & ISS1. 
          I changed WOCE SECT "S4" to S04" for STNNBR 47764 and changed name of 
            .SUM file to s04_su.txt.
          EXPOCODES not yet changed.

05/09/00  Gould        CTD/BTL         Data are Public
          I have just phoned John Gould about the status of the ADOX data 
            (Discovery 200 and 207) that BODC submitted to the WHPO.
          ALL this data is PUBLIC.
          
06/08/00  Bartolacci   CTD/BTL         Website Updated; data unencrypted

07/11/00  Diggs        CTD/BTL/SUM     Submitted (files downloaded)
          SUM, CTD, Bottle: (ctdprs, ctdtmp, ctdsal, ctdoxy, theta, salnty, 
            oxygen, silcat, nitrat, phspht, cfc-11, cfc-12, cfc113, ccl4, 
            revprs, o18/o16)
          Diggs transferred files (again) from BODC site for DI200, DI207 and 
            DI223. Will end up in ftp INCOMING as: 
              2000.07.11_DI2XXX_DIGGS_SUM_SEA_CTD
          Should replace any earlier files (per Martin Gould&#039;s message
            from today - 2000.07.11)
          
07/19/00  Gould        BTL             Data Update: New BTL file updated
          NOTES ON NEW 74DI200: (Q=WHPO  A=Gould)
          Q. No files had leg 1 designators, current holdings have expocode
             74di200_1
          A. They are all leg 1, I should have amended.
          
          Q. SUM: New file has different station numbers.
          A. The old set used BODC reference numbers and not the data 
             originators station identifiers.

          Q  New file uses BE cast codes only (old uses BO only) which 
             causes dates, times and lat/lons to be slightly different relative  
             to the old sum file.
          A. If times are changed then the lat and lon are recalculated from 
             the master navigation. The BEgin times given will have the correct 
             lat/lon. I guess previously our database had bottom times and I 
             changed this to begin and end times, which is what our database 
             should hold.
          
          Q  New file has two additional casts not found in old file:
              74DS200  12361  2  ROS  022693 0344  BE  63°43.32S  84°8.51E  GPS
              74DS200  12361  2  ROS  022693 0344  BE  63°43.32S  84°8.51E  GPS
          A. These 2 are the same. The documents I've provided might hold the 
             answers.
          
          Q. HYD: New file has different station numbers.
          A. Again, the old ones were BODC reference numbers.
          
          Q. New file has no bottle or sample numbers (old bottle file has 
             both).
          A. We do not store bottle or sample numbers. The old bottle numbers 
             will, again, be BODC bottle reference numbers - nothing to do with 
             the actual bottle or sample numbers.
          
          Q. New file does not have CTDRAW (old file does).
          Q. New file does have CTDOXY (old file does not).
          A. I'm not sure about these. We don't store CTDRAW, I don't know why 
             it would have been included, maybe from original data files 
             received and maybe oxygen wasn't available then, or CTD hadn't 
             been linked with the bottle in our database.
          
          Q. New file has NITRAT only, old file has NO2+NO3 (and empty NITRIT).
          A. The new files NITRAT is actually NO2+NO3, we don't have NITRIT by 
             itself.
          
          Q. Values for all nutrients are different between old and new files.
          A. I believe my predecessors never converted from µmol/l to µmol/kg 
             for you. Our database is µmol/l.
          
          Q. New file does not have columns for TCARBN, ALKALI, PCO2, PH.  Were
             these parameters ever taken?
          A. No, these were never taken.
             No samples were taken for carbon 14.
          
          Q. New files have values for ccl4 and o18/o16, old files did not.
          A. Probably never had these at the time of the old submission.
          
          Q. CTD: Difficult to compare CTD files since station numbers are 
                  Different between old and new data sets, as are the dates of 
                  stations/casts.
          A. Please consider the new set as the definitive ones. I've spent a 
             lot of time correcting all sorts of mistakes for UK WOCE data in 
             our database which were submitted in the past. I also re-wrote the 
             WHPO formatting routine to remove things like misleading BODC 
             reference numbers and better conversion from /l to /kg, plus other 
             alterations.
   

07/20/00  Bartolacci   CTD/BTL/SUM     Website Updated  new files online
          SUM, CTD, Bottle: (ctdraw, ctdprs, ctdtmp, ctdsal, theta, salnty, 
          oxygen, silcat, nitrit, no2 no3, phspht, cfc-11, cfc-12, cfc113, 
          revtmp, tcarbn, alkali, pco2, ph, qualt1)
          
          As per Gould. All current files (sum, bottle, and CTD) have been 
          replaced with new files obtained from ftp site by S.Diggs.**Note 
          new files have distinct differences relative to current holdings 
          (i.e. different station numbers, different cast codes/times/lat/lon, 
          parameters) differences are noted in README file in original 
          subdirectory. Gould will be notified on these findings. Still no word 
          on whether C14 was taken (Still have incomplete doc file up on 
          website).
          
          NOTES ON NEW 74DI200:
          No files had leg 1 designators, current holdings have expo 74di200_1
          
          SUM: New file has different station numbers.
            New file uses BE cast codes only (old uses BO only) which causes
              dates, times and lat/lons to be slightly different relative to the
              old sum file.
            New file has two additional casts not found in old file:
              74DS200  12361  2  ROS  022693 0344  BE  63°43.32S  84°8.51E  GPS
              74DS200  12361  2  ROS  022693 0344  BE  63°43.32S  84°8.51E  GPS
          
          HYD: New file has different station numbers.
            New file has no bottle or sample numbers (old bottle file has both).
            New file does not have CTDRAW (old file does).
            New file does have CTDOXY (old file does not).
            New file has NITRAT only, old file has NO2+NO3 (and empty NITRIT).
            Values for all nutrients are different between old and new files.
            New file does not have columns for TCARBN, ALKALI, PCO2, 
              PH were these parameters ever taken?  
           New files have values for ccl4 and o18/o16, old files did not.
          
          CTD: Difficult to compare CTD files since station numbers are 
            different between old and new   data sets, as are the dates of 
            stations/casts.

08/02/00  Kappa        DOC             asked r.r. dickson to submit final doc

08/08/00  Gould        NUTs            Data (units) updated
          The new files NITRAT is actually NO2+NO3, we don't have NITRIT by 
          itself.
          
          I believe my predecessors never converted from µmol/l to µmol/kg 
          for you. Our database is µmol/l.
          
          Please consider the new set as the definitive ones. I've spent a 
          lot of time correcting all sorts of mistakes for UK WOCE data in 
          our database which were submitted in the past. I also re-wrote the 
          WHPO formatting routine to remove things like misleading BODC 
          reference numbers and better conversion from /l to /kg, plus other 
          alterations.

08/11/00  Bartolacci   CTD/BTL/SUM     Expocode, NUTs units updated
          As per Gould's email, I have edited all the expocodes to now 
          include the leg "_1". Also confirming that all nutrients in the 
          bottle file obtained on 2000.07.11 have units of µmol/kg. 

08/16/00  Kappa        DOC             Doc Update  pdf version compiled

08/21/00  Huynh        DOC             pdf, txt versions online

02/07/01  Mantyla      NUTs/S/O        DQE Begun
          I would be glad to look over the Indian Ocean data for you. 
          Sarilee has started plotting up I01 for me to start on. - Arnold
          
03/09/01  Diggs        BTL             Update Needed  
          will call A. Mantyla (doing btl DQE) re QC flags

03/09/01  Diggs        BTL             QC flags omitted, needs reformatting
          Updated file received from A. Poisson. Apparently, the bottle 
          flags were omitted, which is the reason for there being less flags 
          than asterisked fields in the original WOCE file. File is MS Excel 
          and will require extensive reformatting. I will get it close to 
          WOCE format and hand off the Sarilee A./Dave Muus for final 
          formatting.

03/13/01  Kappa        Cruise ID       Website Updated; Doc update: 
          i06/i08/iss1 designations deleted
          Meeting w/ Steve Diggs and Danie Bartolocci, decided to limit line 
          designation s04 since no stations seem to touch the iss1 area and 
          there is no other s04 line.  Will verify w/ Jim Swift.

06/21/01  Uribe        CTD/BTL         Website Updated; CSV File Added
          Bottle and CTD exchange files were added to website.

12/26/01  Uribe        CTD             Website Updated; CSV File Added
          CTD has been converted to exchange using the new code and put 
          online. The sumfile has no WOCE SECT ID so the blanks were filled 
          in with DIS93, the cruise is DISCOVERY and was held in 1993.

01/03/02  Hajrasuliha  CTD             Internal DQE completed
          created *check file for this cruise. created .ps files for this 
          cruise.

03/14/02  Min          CFCs            QUALT1 header misaligned
          I have encountered an error while loading the s04hy.txt for our 
          CFC DQE work for S04_I06. It turns out that the position of 
          'QUALT1' on header is aligned at the end of the flag columns 
          instead of beginning of flag columns... The sample and bottle 
          numbers are still entirely -9, so I can't compare with the revised 
          CFC data set I got from the CFC PI.
          
          Tom Haine (now at Johns Hopkins) is the CFC PI for this cruise, 
          and he has recently sent out the revised CFC data to the British 
          data center. He says the center will forward the merged 
          hydrographic data file to WHPO soon.

03/25/02  Bartolacci   CFCs*            New BTL file w/updated CFC's has errors
                                        *cfc-11, cfc-12, cfc113, ccl4
          New bottle file was sent by M. Gould which contains updated CFC 
          data. However, there were 3 problems noted in the new file. File 
          has fewer valid values for these parameters than whpo current 
          online file (station samples that did have data and Q1 flags of 2 
          in old file have missing values and no flags in new file). New 
          file is missing 5 quality bytes from the quality 1 word. Old file 
          contains complete quality word. New file also has differing values 
          for CTDPRS and THETA when compared to old file.
          
          Dr. Gould has been emailed regarding these problems no reply as of 
          this date. New bottle file and pertinant emails reside in the 
          original s04 directory under 2002.03.22_S04_SEA_MGOULD
          
          No action has been taken at this time.

05/25/02  Bartolacci   CFCs            Update Needed
          Thanks for the data, I've had a chance to look at both the S04 and 
          the ISS01 bottle files you sent last week and I have a couple of 
          questions for you.
          
          Both files appear to have the same problems associated with them: 
          Our current online files for these cruises have valid CFC (CFC12, 
          CFC11, CFC113, and CCl4) in them with quality bytes of 2 for many 
          more station/samples than do the new files sent.  Where there were 
          valid data (flagged 2) there are now missing values in the data 
          colums.  (Please refer to our current online bottle files for 
          these cruises versus files sent in email last week.) Could you 
          confirm that this is correct?
          
          Also the quality words for the new files are truncated, and appear 
          to be missing the bytes (Q1 flags) for the updated CFC data, 
          although at this point I've only eyeballed the columns and haven't 
          run any diagnostic software on them yet, but they are in fact 
          missing 5 flags.
          
          And finally, the data for CTDPRS and THETA contain different 
          values in the newly sent files versus the files we currently have 
          online.
          
          Can you advise us on how to handle these differences, or perhaps 
          send corrected versions (in the case of the missing quality 
          flags).

10/28/02  Kappa        DOC             PDF & TXT versions updated
          Both reformatted, both now have CTD "Data Consistency Report",
          Both now have thesse Data Processing Notes.








