Prelimnary Data report
may 15, 1995
A.	Cruise Narrative

A.1	Highlights

A.1.a	WOCE designation: PR6
A.1.b	Expedition designation: 18999105/1
A.1.c	Chief Scientist: Ron Bellegay
A.1.d	Ship: Endeavor
A.1.e	Ports of Call: Esquimalt, B.C., Canada
A.1.f	Cruise Dates: Oct. 17 to Nov. 1, 1991

A.2	Cruise Summary

A.2.a	Geographic boundaries
A.2.b	Total number of stations

	Table 1:   Stations by type
------------------------------------------------------
Sample type		No. stations	Max. depth (m)
------------------------------------------------------	
CTD casts		36		1500 	
Bottle casts		7		4200	
Bucket samples		36		surface	
Sed. Trap Moorings	2		4200	
------------------------------------------------------

A.2.c	Floats and drifters deployed

No floats or drifters deployed

A.2.d	Moorings deployed or recovered

At station AG, sediment trap moorings were recovered and redeployed.  At 
St. P, a trap mooring was lost and a new mooring deployed.  Near MP20, two 
current meter moorings were recovered.  

A.3	List of Principal Investigators for All Measurements

A.4	Scientific Programme and Methods

This was the first WOCE designated cruise along Line RP5, although this 
section has been covered for over 30 years.  After delaying for the time 
necessary to repair the desalinization system on the ship, the cruise set sail 
from Esquimalt harbor on Thursday, October 17, 1991 on board the Canadian 
Naval Auxiliary Vessel ENDEAVOR. Participating organizations were the 
Institute of Ocean Sciences(Pat Bay) and the University of British Columbia.
In order to meet the objective of recovering two sediment trap moorings 
before any infelicity could occur, the ship sailed directly to Station P, 
50 N, 145 W, without taking any measurements. Mooring recovery and 
redeployment were completed at Station P. The ship then immediately sailed 
north to Station AG, 55 N, 145 W to recover and redeploy the second sediment 
trap mooring. Bottle casts were done at Station AG together with a CTD 
comparison. CTD casts were completed on 46 stations along the return track to 
Station P and along Line P. Bottle reversing thermometer casts were done at 
Stations P (MP26),  MP20, MP18, MP16, MP06, and MP04. Near station MP20, two 
current meter moorings were recovered for the Quiet Eddy Program. The ship 
docked in Esquimalt harbor on the morning of Nov 1.

The cruise began in moderate seas following a fall storm and enjoyed good 
weather and low sea state for the balance of the time.

Most post-cruise effort has gone into inspection of T/S data quality.  
Routines have been revised for correcting CTD profiles, eliminating most of 
the error from instrument drift.  Comparisons of bottle cast and CTD data show 
a slight but significant temperature offset between the two sampling 
procedures that demands closer inspection.  Inspection of oxygen data show that
we must use larger Niskin samplers to increase the flushing time of sample 
bottles, as an initial step in improving this data.  We will also be checking 
flask calibrations to see if these are changing with time.

A.5	Major Problems and Goals not Achieved

The cruise was delayed to allow temporary repairs to the freshwater generating 
system which had been damaged by corrosion and continued to threaten to limit 
the endurance of the cruise. Under the limitations imposed by this problem, the
cruise did well to achieve the major objectives of the program.

On Oct. 21, a sediment trap mooring was released and partially recovered when 
a kevlar splice parted and the instruments and acoustic release sank to the 
bottom. A further recovery attempt using a ROV is under consideration.

Nutrient samples were frozen because analytical instrumentation did not return 
to Victoria soon enough to be put aboard the ship.  Consequently, data quality 
will be reduced.

The calibration thermistor case attached to the CTD started leaking during the 
first cast sending one thermistor off scale and affecting the second 
thermistor at about 1000 m. As a result there was only a partial check on 
in-situ temperatures which indicated a temperature .002 higher than the final 
calibrated temperature for that cast.

The thermistors were removed and the connector was insulated from the 
seawater. Subsequent inspection showed a micro-hole in a solder joint. Since 
the case was being flooded at the time this information was not deemed 
reliable enough to be used except as a rough indication of agreement between 
the CTD and the thermistors. In future, this sensor unit, which had never been 
under pressure before, will be pressure tested before a cruise.

Goals achieved
Line PR6 was completed.
Not achieved
Line PR5 was not occupied .


A.6	Other Incidents of Note

A.7	List of Cruise Participants

		Table 2: List of Cruise Participants
	-----------------------------------------------------
	Name		Responsibility		Affiliation*
        -----------------------------------------------------	
	R.D. Bellegay	Moorings/sampling	IOS	
	R.G. Perkin	CTD			IOS	
	B.G. Minkley	T/S/O			IOS	
	L.A.F. Spearing	Moorings/CTD casts	IOS	
	T.J. Soutar	Electronics		IOS	
	J. Wu		C & N isotopes		DOUBC	
	R. Mugo		Trace metals		DOUBC	
	H. McLean	Trace metals		DOUBC	
	M. Dempsey	Moorings		Oceanetics 	
        ----------------------------------------------------
	*See Table 3 for list of Institutions


		Table 3: List of Institutions
        ----------------------------------------------------------------------
	Abbreviations			Address
 	----------------------------------------------------------------------
	IOS				Institute of Ocean Sciences 
					9860 West Saanich Road, Sidney, B.C. 
					Canada,  V8L 4B2

	DOUBC				Department of Oceanography 
					University of B.C., Vancouver, B.C.

	Oceanetics			Oceanetics Measurements Inc. 
					Sidney, B.C.
   	----------------------------------------------------------------------


B.	Underway Measurements

B.1	Navigation and bathymetry
B.2	Acoustic Doppler Current Profiler (ADCP)
B.3	Thermosalinograph and underway dissolved oxygen, fluorometer, etc.
B.4	XBT and XCTD
B.5	Meteorological observations
B.6	Atmospheric chemistry

C.	Hydrographic Measurements

Water sampling

Niskin samplers (1.7 L) were used for all hydro casts.  Water samples were 
collected in the order O2, TCO2 (not on every cast), nutrients and salinity.  
Oxygen samples were immediately pickled with standard reagents 
(Carpenter, 1966) and the temperature of the sample recorded using a Guildline 
Model 2175A digital thermometer.  TCO2 samples were pickled with HgCl2, and 
cool stored for future analysis.  Nutrients were only sampled to 500 m and 
were frozen for future analysis, since our Autoanalyzer had not returned from 
a joint program with USSR.  Salinity samples were drawn into borosilicate 
bottles for analysis onboard ship.  Rinses for gas samples are likely 
insufficient, due to the limited amount of water available in 1.7 L Niskins.  
Future cruises will employ 10 L Niskins.

Hydro cast temperature and depth

Reversing thermometers were used to record temperature and provide correct 
depths on all hydro casts.  Protected thermometers were used in pairs, and an 
average value recorded, unless there was a discrepancy greater than 0.04o C.  
Then thermometers were cross checked with those that were known to be 
consistent.  This ongoing process removed thermometers that were not properly 
working or were in need of recalibration.  Unprotected thermometers were used 
to estimate the bottle depths.

Oxygen 

The micro-Winkler procedure of Carpenter (1966) with a starch end-point 
titration was used.  After the first 3 hydro casts, the sulfuric acid 
concentration was increased from 280 mL/L acid, to 420 mL/L to improve the 
dissolution of the precipitate.  Duplicate samples drawn from the same bottle 
did not show good agreement.
		 
Depth Range(m)	Conc. Range (uM/kg)	Sp of pairs  (k = no. of pairs)	
500 to 1500	10 to 35		0.53         (k=6)	
2000 to 4000	55 to 130		1.00         (k=12)	

The major source of error is likely in sample drawing.  Also flask calibrations
need to be verified.

Standards were prepared as outlined in WOCE Report 73/91.  

Nutrients
Since frozen samples provide poor results at high concentrations (especially 
for silicate, see Macdonald and McLaughlin, 198 ), samples were only collected 
to 500m and frozen.  Analyses will be done by standard Technicon procedures, 
for NO3 & NO2, PO4 and dissolved Si.

Salinity

A Guildline Model 2400 Autosal (SN 40.364) was used onboard ship to analyze all
samples except for those from the last hydro cast.  Because the instrument 
became unstable near the end of the trip, samples from station MP04 were 
analyzed at IOS using a Guildline Model 2410 Salinometer (SN 58879).  IAPSO 
Standard Seawater batch P115 was used for daily calibrations.

Duplicate samples from 2000 to 3800 m, run in sequence, had a standard 
deviation Sp = 0.001 (k=9), confirming that sampling and analyses are precise, 
and that Niskin bottles were not leaking (since a salinity gradient is evident 
in leaking bottles). 

CTD

CTD casts were done using one of two Guildline instruments with 
intercomparisons at stations with bottle casts. CTD-5 (an Arctic version of 
Guildline Model 8705) was equipped with a 3-bottle Rosette triggered 
electronically from the surface without interrupting the cast; It also had a 
pair of narrow range thermistors to verify the main temperature sensor. 
Calibration samples from the rosette were transferred into borosilicate 
bottles provided by the Standard Seawater Service and analyzed for salinity 
using an Autosal salinometer either aboard the ship or shortly after landing 
at Esquimalt. A summary of the bottle calibrations is given in Table 4,5,6. 
Both CTD's were recalibrated in a lab shortly after returning to IOS.

Calibrations and Standards
The digital CTD(Model 8706 and 8715) probes used during this cruise are made 
by Guildline Instruments of Smiths Falls, Ontario, Canada. Their resolution 
and accuracy are given in the following table.

Table 4. Oxygen: standard deviation of pairs 

Sp = {(sum d2)/2k}1/2, d is difference between pairs, and k is the number of 
pairs.
-------------------------------------------------------------------
Variable	Accuracy	Resolution	Stability	
-------------------------------------------------------------------
Conductivity	.005 psu	.001 psu	.002 psu/6 months	
Temperature	.005		.001		.002/30 days	
Pressure	.15% FS		.01% FS	 	FS = 1500 dbar	
-------------------------------------------------------------------

Pre-cruise calibrations for CTD-5 were as follows

	Table 5 Guildline CTD specifications.
-------------------------------------------------------------------------------
Sensor		#Slope		Offset		Date		Standards
------------------------------------------------------------------------------
Conductivity	1.00032		-.00021		June 19,1991	Batch No.P106
Temperature	.999762		.0055		Oct. 15, 1991	NRC of Canada*
Pressure(@15oC)	1.001566	.55		Oct. 15,1991	Ashcroft 1305B 
F.S.=1500 dbars							deadweight 
								Tester: .1% of 
								F.S.	
Pressure(@8oC)	1.003943	-.93		Oct. 15,1991	Ashcroft 1305B 
								deadweight 
								Tester: .1% of 
								F.S.	
Thermistor #810	1.0000		0.000		Oct. 15, 1991	NRC of Canada*
Thermistor #811	1.0000		0.000		Oct. 15, 1991	NRC of Canada*
------------------------------------------------------------------------------
* Temperature calibrations traceable to the Temperature Standards Lab. of the 
National Research Council of Canada: accuracy = .002 C and are maintained with 
triple point cells. Corrected variable = Measured variable*Slope+Offset

Post-cruise calibrations for CTD-5 were as follows:
 	Table 6 Pre-cruise calibrations.
------------------------------------------------------------------
Sensor		Slope	Offset	Date		Standards	
------------------------------------------------------------------
Conductivity	1.00009	-.00021	Nov. 12,1991	Batch N0. P106, 	
Temperature	.999762	.0072	Nov. 12, 1991	NRC of Canada*	
------------------------------------------------------------------

The temperature correction was averaged between the pre and post cast values. 
The difference of .00170 in the calibrations is at the estimated limit of 
accuracy of the calibration bath system.

The pressure sensor was not recalibrated.

The conductivity sensor was calibrated using the salinities from the rosette 
samples. Table 7 gives a summary of the computed cell constants normalized to 
the pre-cruise value. These are plotted in Fig. 3 and show a systematic change 
over the first 4 casts amounting to .014 in salinity equivalent. The cell 
constant remained constant for the remaining casts and rebounded marginally for
the post-cruise calibration. Additional checks with the hydro-casts and 
comparisons with the other CTD remain to be done.

Near the end of the cruise the Autosal showed signs of increasing drift at the 
.001 level of salinity equivalent. Post-cruise checks could find no problem 
with the electronics or mechanical parts however, a thorough cleaning of the 
cell returned the Autosal to its previous stability.

Fig. 2 shows the CTD/rosette with a bumper attached to the bottom of the 
pressure case for added weight and protection. The performance of this system 
was tested by triggering three bottles through strong salinity/temperature 
gradients in the presence of moderate wave action. The bottles could be made 
to agree with the CTD only after applying a 5.5 m long running mean to the CTD 
data. This suggests that the bumper was causing a significant wake which 
interfered with the flushing of the bottles. Because of the low gradients in 
the deeper water, this effect was significant at only one of the calibration 
bottles and the filter was applied bringing this salinity into line. 
Modifications are under consideration to eliminate this wake effect.

Some samples were lost because of the dislodging of O-rings when the rosette 
bottles were triggered. O-rings with greater stretch are being installed for 
future cruises.




Carpenter, J.H.  1965. The Chesapeake Bay Institute technique for the Winkler
dissolved oxygen method.  Limnol. Oceanogr., 10: 141-143.

Macdonald, R.W. and McLaughlin, F.A.  1982.  The effect of storage by freezing
on dissolved inorganic phosphate, nitrate and reactive silicate for samples
from coastal and estuarine waters.  Water Res. 1: 95-104.


 Table 7. IOS (Pat Bay) Cruise 91-15: Summary of CTD calibration
	  bottle data
------------------------------------------------------------------------------
									
1503	270.00	O-ring rolled						

1503  505.60  3.606 0.739864 34.1828 0.739790 0.999901 0.999909 34.1832 -0.0003
1503  706.50  3.235 0.736276 34.2821 0.736211 0.999912 0.999909	34.2819	 0.0001
1503  706.50  3.235 0.736276 34.2821 0.736211 0.999912 0.999909	34.2819	 0.0001
1504  253.40  3.762 0.736357 33.9677 0.736157 0.999728 0.999827	33.9678	 0.0001
1504  253.40  3.762 0.736357 33.9675 0.736153 0.999723 0.999827	33.9678	-0.0003
1504 1007.20  2.741 0.731674 34.4039 0.731538 0.999815 0.999827	34.4044	-0.0005
1504 1007.20  2.741 0.731674 34.4043 0.731546 0.999825 0.999827	34.4044	-0.0001
1504 1494.30  2.220 0.728098 34.5205 0.727980 0.999838 0.999827	34.5201	 0.0004
1504 1494.30  2.220 0.728098 34.5203 0.727976 0.999833 0.999827	34.5201	 0.0002
1516  649.80  3.673 0.743084 34.1973 0.742908 0.999763 0.999778	34.1979	-0.0006
1516  649.80  3.673 0.743084 34.1971 0.742904 0.999758 0.999778	34.1979	-0.0008
1516 1000.00	O-ring rolled						
1516 1519.00  2.342 0.730424 34.4976 0.730258 0.999773 0.999778	34.4977	-0.0002
1516 1519.00  2.342 0.730424 34.4993 0.730292 0.999819 0.999778	34.4977	 0.0016
1526  597.60  3.768 0.743252 34.1313 0.743028 0.999698 0.999648	34.1294	 0.0019
1526  597.60  3.768 0.743252 34.1309 0.743020 0.999688 0.999648	34.1294	 0.0015
1526  997.60  3.001 0.735975 34.3539 0.735768 0.999719 0.999648	34.3512	 0.0027
1526  997.60  3.001 0.735975 34.3535 0.735761 0.999709 0.999648	34.3512	 0.0023
1526 1500.00 O-ring rolled						
1531  500.00 O-ring rolled						
1531 1000.64  3.038 0.736826 34.3543 0.736553 0.99963  0.999648	34.3550	-0.0007
1531 1000.64  3.038 0.736826 34.3539 0.736545 0.999619 0.999648	34.3550	-0.0011
1531 1500.48  2.358 0.730580 34.4911 0.730275 0.999583 0.999648	34.4936	-0.0025
1531 1500.48  2.358 0.730580 34.4936 0.730324 0.99965  0.999648	34.4936	 0.0001
1538 1000.98  3.257 0.741252 34.3511 0.740956 0.9996   0.999648	34.3530	-0.0018
1538 1000.98  3.257 0.741252 34.3513 0.740960 0.999605 0.999648	34.3530	-0.0016
1538 1492.65  2.404 0.731586 34.4987 0.731278 0.999579 0.999648	34.5014	-0.0027
1538 1492.65  2.404 0.731586 34.4999 0.731301 0.99961  0.999648	34.5014	-0.0015

Nov. 1, 1991								
1538  499.51  4.606 0.758158 34.0653 0.757869 0.99962  0.999648 34.0664	-0.0011
1544  498.49  5.010 0.766610 34.0753 0.766367 0.999683 0.999648	34.0739	 0.0013
1544  998.78  3.503 0.746260 34.3556 0.746044 0.999711 0.999648	34.3533	 0.0024
1544  998.78  3.503 0.746260 34.3580 0.746090 0.999772 0.999648	34.3533	 0.0047
1544 1497.48  2.444 0.732624 34.5097 0.732346 0.999619 0.999648	34.5108	-0.0011
1544 1497.48  2.444 0.732624 34.5115 0.732379 0.999665 0.999648	34.5108	 0.0007
1546  533.67  4.849 0.764445 34.1138 0.764189 0.999666 0.999648	34.1131	 0.0007
1546  533.67  4.849 0.764445 34.1117 0.764146 0.999609 0.999648	34.1131	-0.0015
1546  798.32  4.042 0.754001 34.2885 0.753752 0.99967  0.999648	34.2876	 0.0008
1546  798.32  4.042 0.754001 34.2886 0.753756 0.999675 0.999648	34.2876	 0.0010
1546  997.61  3.524 0.747389 34.3872 0.747088 0.999598 0.999648	34.3891	-0.0019
1546  997.61  3.524 0.747389 34.3866 0.747077 0.999582 0.999648	34.3891	-0.0025
								RMS	0.0016

BOTTLES TRIGGERED IN UPPER 50 M IN A STRONG GRADIENT(not used for calibration)
									
1548   39.71  9.294 0.815481 32.4259 0.814533 0.998838 0.999648 32.2750  0.1509
1548   39.71  9.294 0.815481 32.4244 0.814498 0.998795 0.999648 32.2750  0.1494
1548   46.29  8.429 0.798776 32.4758 0.798004 0.999035 0.999648 32.4782 -0.0024
1548   46.29  8.429 0.798776 32.4778 0.798047 0.999088 0.999648 32.4782 -0.0004
1548   50.29  8.130 0.793064 32.5046 0.792587 0.999399 0.999648 32.5050 -0.0004
1548   50.29  8.130 0.793064 32.5055 0.792609 0.999426 0.999648 32.5050  0.0005
------------------------------------------------------------------------------
Comments: Cast No 1504,1548 were filtered, Cast No. 1526 triggers missing
          for cast

D.	Acknowledgments

E.	References

Unesco, 1983. International Oceanographic tables. Unesco Technical Papers in 
Marine Science, No. 44.

Unesco, 1991. Processing of Oceanographic Station Data, 1991. By JPOTS
editorial panel.

F.	WHPO Summary


Several data files are associated with this report.  They are the en9105.sum, 
en9105.hyd, en9105.csl and *.wct files.  The en9105.sum file contains a summary
of the location, time, type of parameters sampled, and other pertient
information regarding each hydrographic station.  The en9105.hyd file contains 
the bottle data. The *.wct files are the ctd data for each station.  The *.wct 
files are zipped into one file called en9105.wct.zip. The en9105.csl file is a 
listing of ctd and calculated values at standard levels.

The following is a description of how the standard levels and
calculated values were derived for the en9105.csl file:

Salinity, Temperature and Pressure:  These three values were smoothed
from the individual CTD files over the N uniformly increasing pressure levels
using the following binomial filter-

	t(j) = 0.25ti(j-1) + 0.5ti(j) + 0.25ti(j+1) j=2....N-1

When a pressure level is represented in the *.csl file that is not
contained within the ctd values, the value was linearly interpolated
to the desired level after applying the binomial filtering.   

Sigma-theta(SIG-TH:KG/M3), Sigma-2 (SIG-2: KG/M3), and Sigma-4(SIG-4:
KG/M3): These values are calculated using the practical salinity scale
(PSS-78) and the international equation of state for seawater (EOS-80)
as described in the Unesco publication 44 at reference pressures of the
surface for SIG-TH; 2000 dbars for Sigma-2; and 4000 dbars for Sigma-4.

Gradient Potential Temperature (GRD-PT: C/DB 10-3) is calculated as the
least squares slope between two levels, where the standard level is the
center of the interval.  The interval being the smallest of the two
differences between the standard level and the two closest values.
The slope is first determined using CTD temperature and then the
adiabatic lapse rate is subtracted to obtain the gradient potential
temperature.  Equations and Fortran routines are described in Unesco
publication 44.

Gradient Salinity (GRD-S: 1/DB 10-3) is calculated as the least squares
slope between two levels, where the standard level is the center of the
standard level and the two closes values.  Equations and Fortran
routines are described in Unesco publication 44.

Potential Vorticity (POT-V: 1/ms 10-11) is calculated as the vertical
component ignoring contributions due to relative vorticity, i.e.
pv=fN2/g, where f is the coriolius parameter, N is the bouyancy
frequency (data expressed as radius/sec), and g is the local
acceleration of gravity. 

Bouyancy Frequency (B-V: cph) is calculated using the adiabatic
leveling method, Fofonoff (1985) and Millard, Owens and Fofonoff
(1990).  Equations and Fortran routines are described in Unesco
publication 44.

Potential Energy (PE: J/M2: 10-5) and Dynamic Height (DYN-HT: M) are
calculated by integrating from 0 to the level of interest.  Equations and 
Fortran routines are described in Unesco publication, Processing of 
Oceanographic station data.

Neutral Density (GAMMA-N: KG/M3) is calculated with the program GAMMA-N
(Jackett and McDougall) version 1.3 Nov. 94.  

G.	Data Quality Evaulations
