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Cruise Report: JOIS97
(Updated MAR 2014)



Highlights


A.1.                     Cruise Summary Information

          WOCE Section Designation  JOIS97
Expedition designation (ExpoCodes)  18SN19970924
                Chief Scientist(s)  Dr. James H. Swift / SIO
                             Dates  1997 SEP 20 - 1997 OCT 19
                              Ship  CCGS Louis S. St-Laurent
                     Ports of call  Tuktoyaktuk, NWT, Canada - 
                                    Cambridge Bay, NWT, Canada

                                                  75° 19.4' N
             Geographic Boundaries  158° 1.20' W                140° 47.60' W
                                                  70° 11.92' N

                          Stations  16
      Floats and drifters deployed  0
    Moorings deployed or recovered  0

                     Chief Scientist Contact Information

                             Dr. James H. Swift
                   Scripps Institution of Oceanography
           9500 Gilman Dr, MS 0214 • La Jolla, CA  92093-0214
        TEL: 858-534-3387 • FAX: 858-534-7383 • EMAIL: jswift@ucsd.edu





















Acknowledgements

The SIO work was supported by the U.S. National Science Foundation via grant 
OPP-9709130.  Special thanks to NSF program officers for arranging this ship-
of-opportunity support on short notice.  The work would not have been 
possible without the support of the Canadian Department of Fisheries and 
Oceans, and many colleagues at Canadian and U.S. institutions.  The officers 
and crew of CCGS Louis S. St-Laurent ably supported the sea work.





                             Arctic 97/JOIS Leg 4
                           CCGS Louis S. St-Laurent

                              ODF Cruise Report
                               October 5, 1997

                         Oceanographic Data Facility
                     Scripps Institution of Oceanography
                           La Jolla, Ca. 92093-0214


Summary

A ship-of-opportunity CTD/rosette section was carried out in September, 1997 
north into the Canada Basin of the Arctic Ocean along ca. 140°W. The CCGS 
Louis S. St-Laurent departed Tuktoyaktuk, NWT on 20 September 1997. 16 
CTD/Rosette stations were occupied from 24 September through 15 October. 
Water samples (up to 36) and CTD data were collected in most cases to within 
6 meters of the bottom, for a total of 480 bottles. Salinity, dissolved 
oxygen and nutrient samples were analyzed from every level sampled by the 
rosette, with the exception of a second shallow cast for HCH on station 13. 
The cruise ended in Cambridge Bay, NWT on 19 October 1997.


Scientific Personnel Arctic 97/JOIS Leg 4

                             Scientific Personnel

         Name               Affiliation  Duties
         -----------------  -----------  ---------------------------
         Swift, Jim         SIO/PORD     Chief Scientist
         Adamson, Louise    IOS          HCH, TOT, TON
         Boenisch, Gerhard  LDEO         Helium, Tritium, 180
         Delahoyde, Frank   SIO/STS/ODF  CTD data Processing
         Gershey, Bob       BIO          CFCs, CO2
         Hingston, Mike     BIO          CFCs
         Masten, Douglas    SIO/STS/ODF  Nutrients
         Mattson, Carl      SIO/STS/ODF  TIC/Watch Leader/ET/Rosette
         Muus, Dave         SIO/STS/ODF  O2
         Poliquin, Manon    BIO          CO2
         Rusk, Steve        SIO/STS/ODF  Salts/Rosette
         Sieberg, Doug      IOS/AINA     Rosette/deck
         Tremblay, Bruno    LDEO         CTD/Rosette
         Tuele, Darren      IOS          Rosette/Deck/Bongo tows
         Zemlyak, Frank     BIO          CFCs, CO2




Programs

The principal programs of Arctic 97/JOIS Leg 4 are shown in Table 1.0. The 
SIO ODF hydrographic measurements program is described in detail in this 
report.


Table 1.0: Principal Programs of Arctic 97/JOIS Leg 4

    Analysis                    Institution  Principal Investigator
    --------------------------  -----------  ---------------------------
    Basic Hydrography (Salin-   SIO          J.H. Swift
      ity, O2, Nutrients, CTD)  
    CFCs                        BIO          E.P. Jones
    He, Tr, 18O                 LDEO         P. Schlosser, G. Boenisch
    TCO2, Alkalinity            BIO          E.P. Jones
    Ba                          OSU          K. Falkner
    TOC, TON                    OSU          P. Wheeler
    180                         OSU          K. Falkner
    1291                        BIO          J. Smith
    137Cs                       BIO          J. Smith
    HCH                         IOS          F. McLaughlin, R. Macdonald
    XCTD, Mooring               JAMSTEC      K. Shimada
    Bongo tows                  IOS          F. McLaughlin, R. Macdonald




NARRATIVE

The advance plan for the expedition prepared by the SHEBA Project Office and 
the leaders of the Joint Ocean Ice Study (JOIS) included the following 
elements:

• Recovery of three JAMSTEC current meter moorings off Point Barrow, first by 
  CCGS Laurier, and, if necessary, by CCGS Louis S. St-Laurent.

• Deployment of a JAMSTEC deep water (1500-3000 meter) current meter mooring 
  on the Canada Basin flank of the Northwind Ridge by CCGS Louis S. St-
  Laurent.

• Deployment of a JAMSTEC Ice Ocean Environmental Buoy ("IOEB-2") ice drift 
  mooring in heavy ice off Banks Island from the CCGS Des Groseilliers.

• Occupation of a continental shelf to deep basin CTD/hydrographic section 
  from the Beaufort Sea shelf into the deep Canada Basin from  CCGS Louis S. 
  St-Laurent.  [This is the program reported here.]

• Deployment of CCGS Des Groseilliers for a year-long series of measurements 
  near 75-76°N, 142°W  in an ice floe meeting project criteria set by the 
  Surface Heat Budget of the Arctic (SHEBA) science team.  This was the 
  primary mission.

The following narrative relates principally to the activities of the Section 
team:

9/18   The JOIS Leg 4 Section science team boarded CCGS Louis S. St-Laurent 
       at Tuktoyaktuk, NWT, Canada ("Tuk"), moored about 20 miles offshore.  
       Two Section team members from Bedford Institute of Oceanography and 
       two from the Institute of Oceanographic Sciences, Patricia Bay, were 
       already aboard from Leg 3.  Some scientists from Leg 3 remained on 
       board, anticipating a visit by Canada Minister of Fisheries and 
       Oceans.  SHEBA and Section equipment expected in Tuk via barge from 
       Hey River had been delayed 6-8 days and had not yet arrived at the 
       ship.

9/19   Foggy conditions set in.  The barge arrived in Tuk at night.

9/20   Still foggy.  The barge was towed out to CCGS Des Groseilliers in the 
       evening.  During a planning session JAMSTEC scientist Koji Shimada 
       indicated that the Northwind Ridge was the only acceptable site for 
       deployment of the JAMSTEC mooring scheduled for Leg 4.  JAMSTEC also 
       had an XCTD program along the section, and  IOEB-2 from the Des 
       Groseilliers.  Eddy Carmack proposed a revised science plan calling 
       for CCGS Laurier to make the second attempt to recover the JAMSTEC 
       Barrow Canyon mooring.  The Louis sent the Laurier information about 
       search patterns and release codes.

9/21   Due to continued heavy fog the Louis was unable to load SHEBA 
       passengers.  The Des Groseilliers completed cargo loading by early 
       evening so the Louis  came alongside with the barge in the middle.  
       Seas were light and conditions ideal for loading, so from 7:30 pm to 2 
       am all hands turned out to load cargo.

9/23   Almost all Section systems ready.  But the Louis still could not load 
       the remaining SHEBA passengers due to continued fog, wind, seas, etc.  
       Finally a tug landed them on a nearby island and the ship's helicopter 
       picked them up.  Louis still waiting for engine parts expected via air 
       freight.

       Due to the time lost from the shipment delay and the fog, the SHEBA 
       leaders canceled the attempt to deploy the JAMSTEC Northwind Ridge 
       mooring (at least before the SHEBA set up).  The Louis was asked to 
       begin the Section within the range of 141-145°W. The Des Groseilliers 
       plan was also revised, with no trip to Banks Island, and that vessel 
       then planed to proceed to ice edge at 143°W, then proceed in 50 km and 
       attempt to deploy IOEB-2.

       The Louis headed overnight from Tuk to the Mackenzie River mouth area. 

9/24   Heavy fog at the airport and ship meant no possibility of transfer of 
       engine parts so at 1100 the Louis left for the west to the 50 meter 
       isobath along 141° 30'.  This was east of the original plan, but west 
       of the Mackenzie River delta region.  The Section began after the 
       evening meal.  Finished the first four stations (planned/actual depths 
       50/41, 100/102, 200/247, and 500/490 meters) by midnight.  All went 
       very well.  A leak test on all the unused bottles at Station 1 found 
       one leaker, which was repaired before it ever had to be used on a real 
       sample.  Stations consist of 1 CTD cast to the bottom, and up to 30 
       minutes of bongo net tows.  XCTDs were deployed by Koji Shimada from 
       JAMSTEC at locations of his choosing.

       The Des Groseilliers was not yet able to cross to the ice edge due to 
       heavy load plus sea conditions.

9/25   Resumed science work at 0830 and completed four more stations 
       (planned/actual depths 800/1035, 1100/1820, 1500/2410, and 2000/2868 
       meters), for eight total.  It was decided that net tows and CTD casts 
       could proceed in tandem.  Lost use of the depth sounder en route to 
       station 5.  Last reading of ca. 730 meters turned out to be erroneous 
       because the actual water depth was about 1035 m.  Possible very steep 
       bathymetry.  Decided on the basis of T and S CTD profiles that the 
       Station 4 to Station 5 transition could be interpolated, so did not 
       try to go back for the planned intermediate depth.  There was no depth 
       sounder en route to Station 6 and so the Louis proceeded 6 miles (to 
       the original Station 8 position) and did a cast.  The Section work 
       otherwise was nearly without flaw.

       The weather was good for station work, with roll never a problem 
       and seas and winds steadily decreasing.  Air temperature slightly 
       positive.  The Louis was joined by a young golden eagle which probably 
       got lost in the fog.

       In a conversation with the Captain regarding additional stations it 
       was clear that he strongly preferred to not do any station work after 
       leaving the SHEBA site.  But it would take more time than available to 
       reach the ice edge at the planned 18-20 mile spacing, plus there was 
       ca. 120 miles of ice transit to the SHEBA site, and the Des 
       Groseilliers was expected soon at the ice edge, so it was going to be 
       impossible to continue short spacing.  The portion of the Section 
       expected to benefit most from short spacing had been completed, and so 
       three stations were chosen at nominal 37 mile spacing to take the 
       Louis to the ice edge.

9/26   An almost ideal day of station work.  Weather remained good with light 
       winds (10-15 knots), air temperature near or a little above 0°C, grey 
       skies, light seas and swell.  Completed three deep stations, with the 
       last, #11, near the ice edge.  The eagle departed as the Louis neared 
       ice floes.

       The (revised) Section plan for remaining stations was to continue with 
       20-37 mile spacing in the ice to the SHEBA site (including a double 
       cast near SHEBA), to do 1-2 stations north of SHEBA, and to do daily 
       CTD casts near SHEBA, in that priority order.  The first two were part 
       of the original science plan.  The Louis proceeded from Station #11 24 
       miles north and west, to within sight of Des Groseilliers in 8/10 
       loose multi-year ice.

9/27   Air temperature -4°C, winds light.  Had one or more bears close by 
       the ship overnight.  There was no CTD cast at the initial rendezvous 
       point because the captains chose to proceed directly into the ice.  As 
       the distance from Station 11 began to exceed 40 miles, it started 
       becoming urgent to do a station.  Also, the Louis received from Des 
       Groseilliers information about a submarine visit to the SHEBA area 
       (the SCICEX sub) with a request/demand from the US Navy for no 
       instruments in the water during 0000Z 9/28 to 0000Z 10/2 in an area 
       125 km from 75° 30'N 145°W.  Although the Louis was well outside the 
       area, and somewhat outside the time, someone from SHEBA had 
       interpreted this to mean no over the side operations beginning 
       immediately and anywhere.  The Section team finally received 
       permission from the SHEBA Chief Scientist to do a cast if it were 
       completed before 0000Z 9/28.  A handsome lead presented itself, the 
       Captain was persuaded to stop in it, and the Station 12 CTD cast was 
       out of the water before 2345Z 9/27.

9/28   The vessels proceeded in 10/10ths 1st year ice with some multiyear 
       ice.  Air temperature was -8°C, sky overcast with snow flurries.  
       Foggy in the morning improving to high clouds, some sun, and only 
       light haze in afternoon.  Had ca. 65+ miles to go (straight line) to 
       new IOEB site (75° 10'N, 143° 20'W) ca. 50 km SE of intended SHEBA 
       floe (75° 30'N, 141° 30'W).  SHEBA team noted it will permit a CTD 
       cast at the IOEB site.

       Data quality very good.  The main problem has been that that the 
       oxygen autotitrator produces occasional bad results.  Apparently this 
       is typical of recent expeditions, but with cause unknown, except that 
       it is thought to be some software glitch.  The cut-back in the number 
       of stations has left only single stations in many of the features.  
       Spatial scales may thus be hard to assess for some aspects of the 
       lateral variability.  The Section CTD wire time so far was only a 
       small part of that allotted in the pre-cruise agreement/plan.

       The SHEBA team from the Des Groseilliers found a target floe for 
       SHEBA.  Meanwhile, the SHEBA team sent the Louis and the Des 
       Groseilliers ENE to a new position for the JAMSTEC IOEB-2 drift array 
       near 75° 10' N, 140° 20' W.  The plan was to put in that array and 
       then proceed to the new SHEBA location at 75° 30' N, 141° 30' W.

9/29   Nice morning with 10 knot winds out of the north, -10°C, mostly 
       10/10ths ice cover though a few leads.  In the late afternoon the 
       ships arrived at a site acceptable to the JAMSTEC IOEB-2 team.  Des 
       Groseilliers was unable to get into position next to the floe without 
       damaging the floe and determined to try again the next day.

9/30   Mostly cloudy with some snow flurries and haze — not good long 
       distance flying weather.  Remaining -10°C and lighter wind.  Des 
       Groseilliers spent about an hour or more after first light again 
       trying to position themselves and succeeded.  The Section team did 
       Station 13 cast 1.  All went well, though for the first time the 
       conductivity sensor froze during launch.  The rosette (and sensor) was 
       warmed in the water, raised to 5 m, and then relowered.  This appeared 
       to have changed the conductivity calibration.  The Des Groseilliers 
       spent the day implanting IOEB-2 while the Louis stood by about one 
       mile away.  JAMSTEC asked for a second CTD cast to at least 200 m 
       after deployment of IOEB-2, and this was completed without sensor 
       freeze problems.

10/1   The morning was cold (-15°C) with light winds and snow flurries.  
       Visibility flat, with some haze, and this hindered helo ops, for 
       example to deploy SHEBA remote sites and to survey the SHEBA floe.  A 
       low pressure system lay to the west just NW of Bering Strait.  The 
       vessels moved to about 600 meters from the SHEBA floe at 75° 11' N, 
       142° 24' W.  The ice was more fragile than expected, so Des 
       Groseilliers tried to cut her own way in.  The Section team carried 
       out CTD station 14 after 1600 l.t., when the Navy-caused ban expired.  
       During Station 14 there was a problem on the down cast when a strand 
       broke loose from the CTD cable and got wrapped into the rollers on the 
       winch.  This took ca. 25 minutes to fix.  Otherwise the cast went OK.  
       This was an HCH profile. A double cast was avoided because this 
       station was only 12 miles from Station 13 and Gerhard Boenisch decided 
       that he did not need a He/Tr profile.

10/2   The low pressure system over Bering Strait intensified, but despite 
       early indications of worsening weather, the storm delayed, and the day 
       turned out to be a fine one, with good visibility and contrast, good 
       flying conditions, winds ca. 15 knots, and air temperature 13°C.  The 
       Des Groseilliers moved into the SHEBA floe after an advance team on 
       snowmobiles picked an entry path and "docking" place.  Later, the 
       Louis followed, though about 1/4 to 1/2 mile from the other ship.  The 
       science group on the Louis had their first visit from the SHEBA 
       leaders, who came over from Des Groseilliers.  Still predictions of 
       storm conditions.

10/3   The low pressure system moved south of SHEBA.  This brought brisk 
       winds from the east, up to 25-35 knots, with periods of blowing snow.  
       Air temperature -10°C.  Working conditions remained acceptable 
       throughout the day, but the weather was not suitable for flying.

       A polar bear came by in the morning before work parties got going.  
       The Des Groseilliers dispatched an armed team on snowmobiles to scare 
       it off.

10/4   The low continued to move east, well south of SHEBA.  A high pressure 
       system to the west spelled improving conditions.  Morning winds were 
       30 knots and air temperature was -9°C.  By midday visibility was very 
       good and helicopter operations resumed.  The Louis began unloading 
       large items such as the 40-foot "Welch" van, caterpillar bulldozer, 
       "fast track" vehicle, and some fuel drums.

10/5   High pressure building over the area.  Air -15.5°C this morning, and 
       winds remained 20 knots or better.  Snow flurries and poor visibility 
       in the morning.  The Des Groseilliers team asked for assistance from 
       extra science hands on the Louis.  Jumper Bitters, the key logistics 
       person for SHEBA, was injured in a snowmobile accident, and late in 
       the day was airlifted to Barrow via a Twin Otter from Barrow Search 
       and Rescue, which landed on the runway he was just on his way to 
       improve when the accident happened.

10/6   Low pressure intensified west of Bering Strait, over Siberia, shifting 
       wind direction somewhat.  Air temperature -18°C today.

10/7   Foggy (very thin layer) morning, air temperature -19°C, dropping to 
       -22°C.  Light winds.  Nice afternoon.

10/8   Air -23°C in the morning, winds light but picked up to 20 knots later 
       in the morning and 30 by afternoon, with blowing snow by evening.  Air 
       steadily warming all day.  Found out that Louis may leave as soon as 
       10/10 in order to put in the Northwind Ridge mooring.  This has 
       occasioned some last-minute shuffling of cargo.

10/9   Air -9°C in the morning, with some blowing snow.  Louis moved to Des 
       Groseilliers for refueling.  By afternoon there was a gangway between 
       the two vessels and some additional items were moved.

10/10  Air -16°C in the morning, and to -18°C later in the day.  Louis still 
       refueling Des Goseilliers.  Had to dig the IOS Niskin bottles (for Des 
       Groseilliers) out of the forward cargo hold, where they were deeply 
       buried.  Did not find any messengers for them.  Excess ship crew moved 
       aboard Louis from Des Groseilliers.  The plan was to deliver them to 
       Prudhoe Bay before going to Northwind Ridge.  Louis to be at maximum 
       capacity (100) until then.

10/11  Air -15°C in the morning.  Good weather predicted next two days, plus 
       ice map showed the Northwind Ridge mooring site in open water near the 
       ice edge.  Five more stations were planned, for a total of 19 this 
       cruise.  The day turned out with zero progress because the Louis 
       developed problems with the main propulsion motor (center shaft) 
       during the time it was leaving SHEBA, and found that without the 
       center screw — which feeds to the rudder — it was just too hard to 
       maneuver in the ice, so the vessel was stopped, still in the main 
       SHEBA floe, after only a mile or so of progress.  The helicopter group 
       did not get to fly either.

10/12  Air temperature -16°C; a nice day.  A low pressure system formed 
       north of eastern Siberia, farther north than others during the last 
       few weeks.  Motor repairs completed shortly before noon, but the Louis 
       was underway only to stop a short time later to keep helicopter 
       operation range within bounds.  The ship was less than one mile from a 
       great lead and it took some persuading to get the Louis moved into the 
       lead to get a station done while the ship waited for the helicopters.  
       The Louis then departed the SHEBA vicinity for a night run through the 
       ice.

10/13  Cloudy but good visibility.  Air temperature -12°C.  A very 
       disappointing night for the Section program because the Louis steamed 
       past both remaining fill-in station locations.  The Captain's answer 
       to the request for two "fill in" stations (for the US Navy-caused gap 
       on the way in) was to give instructions the mates only to make 
       maximum southward progress overnight.  And when the Louis left the ice 
       the speed had to be cut to under 8 knots for the last 17 hours of the 
       run to Prudhoe to avoid arriving too early!

10/14  Offshore of Prudhoe Bay in the morning.  Lights of drilling platforms 
       visible.  Cloudy but good visibility.  Air temperature -4°C.  28 SHEBA 
       and Des Groseilliers passengers plus Louis crew transferred ashore via 
       helicopter.  Heading to Northwind Ridge at 16 knots.  Captain refused 
       JAMSTEC request to slow to 12 knots for XCTD casts.

10/15  The Louis made good progress overnight and was coming on to the 
       intended mooring area, based on bathymetric charts, at 0800 ship time.  
       The air chilled from -5°C to -9°C during the day, and winds were 25-30 
       knots, though did not overly disrupt operations.  The Louis 
       encountered no ice en route, although there was grease ice in the 
       mooring area.  The science party began a bathymetric watch at 0630, 
       looking for the 3000 (± 20) meter isobath for the JAMSTEC mooring.  
       The slope must have been very steep because this became an impossible 
       operation.  The bottom trace on the depth sounder was lost approaching 
       the mooring site, with the last reading of ≈3800 meters.  A CTD cast 
       at the site showed that the Louis was in only 1470 meters of water, 
       instead of the ca. 3000 expected from the chart.  On trying to do a 
       bathymetric survey towards deeper water, the sounder trace was lost 
       again at 2000 meters, and never regained in deep water.  Koji Shimada 
       decided to deploy the mooring at the 1500 meter isobath instead (not a 
       problem), and Doug Sieberg and JAMSTEC were convinced to go for 
       anchor-last instead of anchor first deployment.  This lost some time 
       initially but the mooring deployment itself went OK.  The sounder's 
       bottom trace returned when the vessel crossed into water shallower 
       than 2000 meters.  At 0058 UT the JAMSTEC Northwind Ridge mooring was 
       launched at the prime location near 74° 30' N, 158°W, in 1500 meters 
       water depth.  After launch, one acoustic release did not respond to 
       interrogation, but the other release did respond.  An important deep 
       CTD cast 7 miles to the SE had been planned to establish lateral 
       gradients across the current, and to get the CTD wire level wound 
       better for storage, but the Captain summarily cancelled it, ordered 
       the ship east, but then held speed down overnight in good weather.  
       The speed decrease alone more than covered the time needed earlier for 
       the lost station, further upsetting the JAMSTEC and Section groups.

       Sixteen CTD stations were completed, with total of 24.4 hours wire 
       time used, out of 72 hours allotted in the science plan.  The 
       Captain's peremptory cuts deleted >20% from the Section program (in 
       terms of wire time), in addition to the large cut-backs that were 
       made with science team approval to fit within the reduced science time 
       available.  The JAMSTEC and Section groups noted to each other that 
       science missions are best carried out using vessels with science-
       supportive captains.

10/16  Steamed to the east in -12°C, 25-30 knot winds.  A wintry day with 
       leaden skies, grease and pancake ice all about, and bitter cold winds. 
       Found the messengers for the SHEBA hydro bottles today.  (!)




1.  HYDROGRAPHIC MEASUREMENTS PROGRAM

Careful CTD work is the hallmark of reference-quality hydrographic 
measurements partly because the interpretation of other data, such as those 
from oxygen, nutrients other tracers, is much enhanced when combined with 
sufficient background information, especially for the parameters needed to 
calculate density, to enable accurate comparisons with other regions and 
times.  Density is closely tied to salinity at the extremely cold 
temperatures typical of the Canada Basin domain.

Scientists and technicians from the Bedford Institute of Oceanography, 
Lamont-Doherty Earth Observatory, Institute of Oceanographic Science 
Patricia Bay, and the Scripps Institution of Oceanography participated in 
Cruise JOIS Leg 4 of the Canadian icebreaker CCGS Louis S. St-Laurent during 
18 September - 19 October 1997, in the waters of the Canada Basin of the 
Arctic Ocean.  The primary goal of this program was to determine the 
surface-to-bottom distributions of  the physical and chemical 
characteristics of Canada Basin waters along a closely-spaced section of 
measurements extending from the Beaufort shelf to the deep Canada Basin, 
specifically to, and if possible beyond, the site selected for the year-long 
ice camp for the SHEBA (Surface Heat Budget of the Arctic) program.  It was 
hoped that the measurements would identify the structure and spatial limits 
of the boundary regime, and relate that to the hydrographic structure of the 
interior of the Canada Basin.  The measurements completed at sea for this 
program include CTDO, salinity, oxygen, nutrients (nitrate, nitrite, 
phosphate, and silicate), chlorofluoromethanes (CFC-11, CFC-12, CFC-113, and 
CCl4), total alkalinity, and total carbonate.  Samples taken to be analyzed 
ashore included helium, tritium, oxygen-18, barium, iodine-129, cesium-137, 
total organic carbon ("TOC"), total organic nitrogen ("TON"), and the 
organic pesticide "HCH".  Other measurement programs on JOIS Leg 4 included 
bongo net tows and XCTD casts.  No reference-quality data of similar scope 
and completeness existed from this domain prior to this expedition.  All 
rosette casts were made to within 10 meters of the bottom, with the 
exception of a second shallow cast for HCH on station 13. No major problems 
were encountered during the operation. The distribution of samples is 
illustrated in figure 1.0

Here are reported preliminary results of the shipboard measurements from the 
rosette water sampler deployed at each station.  Preliminary pressures and 
temperatures during rosette bottle trips are reported from the accompanying 
CTD profiles. These data represent a rare shelf-to-deep-basin section into 
the Canada Basin by a oceanographic expedition equipped for a broad range of 
reference-quality measurements, and we expect considerable interest to be 
generated by these data. 


Figure 1.0: Sample distribution, stations 1-16.


Description of Measurement Techniques

1.1.  Water Sampling Package

Hydrographic (rosette) casts were performed with a 36-place 10-liter rosette 
system consisting of a 36-bottle rosette frame (ODF) and 36 10-liter PVC 
bottles (ODF). Underwater electronic components included:

• SeaBird SBE 32 36-place pylon;
• ODF-modified NBIS Mark III CTD with dual conductivity and temperature 
  sensors and a dissolved oxygen sensor;
• SeaBird SBE 35 reference temperature sensor;
• Simrad altimeter;
• Benthos pinger; and
• FSI ICTD connected to an ODF-built data logger.

The Mark III CTD was mounted horizontally along the bottom of the rosette 
frame, with the dissolved oxygen and SBE 35 temperature sensors deployed 
alongside. The SBE 35 was connected to the SBE 32 pylon, internally recording 
a temperature for each rosette trip. The Simrad altimeter provided distance 
above the bottom in the CTD data stream. The Benthos pinger was not used, as 
the Ship's 12KHz PDR system was not reliable. The FSI ICTD data were 
collected for evaluation purposes.

The rosette system was suspended from a three-conductor 0.322" electro-
mechanical (EM) cable. A single conductor in this cable was used to 
communicate with the CTD and pylon from the ship.

The rosette system was deployed from the midship starboard side boat deck. A 
wheeled cart was used to move the rosette into the sampling van.

The deck watch prepared the rosette 45 minutes prior to a cast. All valves, 
vents and lanyards were checked for proper orientation. The bottles were 
cocked and all hardware and connections rechecked. Upon arrival on station, 
time, position and bottom depth were logged and the deployment begun. The 
rosette was moved into position under an A-frame from the sampling van using 
the wheeled cart. Stabilizing tag lines were threaded through rings on the 
frame. CTD sensor covers were removed. Once the CTD acquisition and control 
system in the ship's laboratory had been initiated by the console operator 
and the CTD and pylon had passed their diagnostics, the watch leader would 
verify with the bridge that deployment could begin. The winch operator would 
raise the package and move the A-frame over the side of the ship. The 
package was then quickly lowered into the water, the tag lines removed and 
the console and winch operators notified by radio of the target depth 
(wire-out).

During each cast, the rosette was lowered to 5-10 meters above the bottom. 
Each bottle on the rosette had a unique identification number. These numbers 
were initially assigned to correspond to the pylon tripping sequence 1-36, 
the first trip closing bottle #1. No bottles were changed during the leg. 
Averages of CTD data corresponding to the time of bottle closure were 
associated with each bottle during a cast.

At the end of the cast, the deck watch snagged the rosette frame with tag 
lines. The package was then lifted out of the water, the A-frame moved 
inboard, and the rosette lowered onto the cart. Sensor covers were replaced 
and the cart and rosette moved into the sampling van for sampling. A 
detailed examination of the bottles and rosette would occur before samples 
were taken, and any extraordinary situations or circumstances noted on the 
sample log for the cast.

Rosette maintenance was performed on a regular basis. O-rings were changed 
as necessary and bottle maintenance performed each day to insure proper 
closure and sealing. Valves were inspected for leaks and repaired or 
replaced.

A broken armor strand on the sea cable (2070 MWO) was discovered on cast 
14/1 and was taped-up. Subsequently, the winch was stopped on both down and 
upcasts to examine the wire.




1.2.  Underwater Electronics Packages

CTD data were collected with a modified NBIS Mark III CTD (ODF CTD #5). This 
instrument provided pressure, temperature, conductivity and dissolved O2 
channels, and additionally provided redundant PRT temperature and 
conductivity channels. Other data channels included elapsed-time, an 
altimeter, and several power supply voltages. The instrument supplied a 
standard 17-byte NBIS-format data stream at a data rate of 20 FPS. 
Modifications to the instrument included revised pressure and dissolved O2 
sensor mountings; an ODF-designed sensor interface for O2; implementation of 
8-bit and 16-bit multiplexer channels; an elapsed-time channel; instrument id 
in the polarity byte and power supply voltages channels. The instrument 
sensor configuration is provided in Table 1.2.0.


Table 1.2.0: CTD #5 sensor configuration data.

  Sensor        Manufacturer         Serial   Notes
  ------------  -------------------  -------  ---------------------------
  Pressure      Paine 211-35-440-05  77017    Primary
  Temperature   Rosemount 171BJ      15407    Primary
  Conductivity  GO 09035-00151       E197     Primary casts 1/01-14/01
  Conductivity  GO 09035-00151       O16      Primary casts 15/01-16/01
  Temperature   Rosemount 171BJ      17534    Secondary
  Conductivity  GO 09035-00151       E184     Secondary casts 1/01-14/01
  Conductivity  GO 09035-00151       O24      Secondary casts 15/01-16/01
  Dissolved O2  SensorMedics         6-02-07  Primary


The CTD pressure sensor mounting had been modified to reduce the dynamic 
thermal effects on pressure. The sensor was attached to a length of coiled, 
oil-filled stainless-steel tubing threaded into the end-cap pressure port. 
The transducer was also insulated. The NBIS temperature compensation circuit 
on the pressure interface was disabled. All thermal response characteristics 
were modeled and corrected in software.

The SensorMedics O2 sensor was deployed in a pressure-compensated holder 
assembly mounted separately on the rosette frame and connected to the CTD by 
an underwater cable. The O2 sensor interface was designed and built by ODF.

A Sea-Bird Electronics SBE 35 (#350006) reference temperature sensor was 
employed as an additional temperature calibration check. Based on 
ultrastable thermistors and reference resistances, this device is 
internally-recording and triggered by the SBE 32 pylon confirmation signal, 
providing a calibration point for each bottle trip. [SBE97]

Standard CTD maintenance procedures included soaking the conductivity and 
O2 sensors in distilled water between casts to maintain sensor stability, 
and protecting the CTD from exposure to weather to maintain an equilibrated 
internal temperature. In spite of these precautions, both conductivity 
sensors were damaged by freezing during the transit to station 15 and were 
replaced.

A Sea-Bird SBE 32 36-place pylon and SBE 33 deck unit were employed 
throughout the cruise. The SBE 32 has the advantage of using a single sea 
cable conductor for power and signals to both CTD and pylon. It also 
directly supports the use of the SBE 35 temperature reference. The pylon 
provided very reliable operation and positive confirmation of all bottle 
trip attempts. There were no mistripped bottles.


1.3.  Navigation and Bathymetric Data

GPS position and bottom depth were logged manually at three times for each 
CTD/rosette deployment: at the beginning of the cast, at the bottom of the 
cast and at the end of the cast. An ELAC 12KHz PDR (provided by IOS) was 
used to determine bottom depth. It proved to be not very reliable in the 
ice, and not usable with the Benthos pinger on the rosette.


1.4.  CTD Laboratory Calibration Procedures

Laboratory calibrations of the CTD pressure and temperature sensors were 
used to generate tables of corrections for sensor calibration models applied 
by the CTD data acquisition and processing software at sea.

Pressure and temperature calibrations were last performed on CTD #5 at the 
ODF Calibration Facility (La Jolla) in August, 1997, prior to Arctic 
971J0I5 Leg 4.

The CTD pressure transducer (Paine 211-35-440-05 8850 psi, Serial #77017) was 
calibrated in a temperature-controlled water bath to a Ruska Model 2400 
Piston Gauge pressure reference. Calibration curves were measured at 0.33 
and 31.49°C to two maximum loading pressures (1194 and 6079 db, figure 
1.4.0).


Figure 1.4.0: Pressure calibration for ODF CTD #5 (Payne #77017), August 
              1997.


CTD PRT temperatures and the SBE 35 temperature reference were calibrated to 
a NBIS ATB-1250 resistance bridge and Rosemount standard PRT. The primary 
(Rosemount 171BJ, Serial #15407) and secondary (Rosemount 171BJ, Serial 
#17534) CTD temperatures were offset by 1.5°C to avoid the 0-point 
discontinuity inherent in the Mark III internal digitizing circuitry. 
Figures 1.4.1, 1.4.2 and 1.4.3 summarize the laboratory temperature 
calibrations performed on the primary, secondary and reference sensors in 
August, 1997. These calibration procedures will be repeated when the 
instrument is returned to ODF.


Figure 1.4.1: Temperature calibration for ODF CTD #5, August 1997.
              Primary PRT #15407.
Figure 1.4.2: Temperature calibration for ODF CTD #5, August 1997.
              Secondary PRT #17534.
Figure 1.4.3: Temperature calibration for reference sensor, August 1997.
              SBE 35 temperature sensor #350006.



1.5.  CTD Data Acquisition, Processing and Control System

The CTD data acquisition, processing and control system consisted of a Sun 
SPARCstation LX computer workstation, ODF-built CTD deck unit, SBE 33 pylon 
deck unit and power supply and a VCR recorder for real-time analog backup 
recording of the sea cable signal. The Sun system consisted of a color 
display with trackball and keyboard (the CTD console), 2 RS-232 ports, 
1.05GB and 1.6 GB disks and 8-mm cartridge tape. Two other Sun systems (one 
Sparc LX, one SparcStation 2) were networked to the data acquisition system, 
as well as to other data acquisition and processing computers used for the 
hydrographic section program. These systems were available for real-time CTD 
data display as well as providing hydrographic data management, storage and 
backup. Two HP 1200C color inkjet printers provided hardcopy from any of
the workstations.

The CTD FSK signal from the sea cable was demodulated and converted to a 
9600 baud RS-232C binary data stream by the CTD deck unit. This data stream 
was fed to the Sun SPARCstation. The pylon deck unit was also connected to 
the Sun through a bi-directional 300 baud serial line, allowing rosette 
trips to be initiated and confirmed through the data acquisition software. A 
bitmapped color display provided interactive graphical display and control 
of the CTD rosette sampling system, including real-time raw and processed 
data displays, navigation, winch and rosette trip displays.

The CTD data acquisition, processing and control system was prepared by the 
console watch a few minutes before a deployment. A console operations log 
was maintained for each deployment, containing a record of every attempt to 
trip a bottle as well as any pertinent comments. Most CTD console control 
functions, including starting the data acquisition, were performed by 
pointing and clicking a trackball cursor on the display at pictures 
representing functions to perform. The system would then present the 
operator with a short dialog prompting with automatically-generated choices 
that could either be accepted as default or overridden. The operator was 
instructed to turn on the CTD and pylon power, then to examine a real-time 
CTD data display on the screen for stable voltages from the underwater unit. 
Once this was accomplished, the data acquisition and processing was begun 
and a time and position automatically associated with the beginning of the 
cast. The backup analog recording of the CTD signal on a VCR tape was 
started. A rosette trip display and pylon control window popped up, giving 
visual confirmation that the pylon was initializing properly. Various plots 
and displays were initiated. When all was ready, the console operator 
informed the deck watch by radio.

Once the deck watch had deployed the rosette, the deck watch leader 
provided the winch operator with a target depth (wire-out) and lowering rate 
(normally 30 meters/minute to 120 meters and then increasing to 60 
meters/minute).

The console operator would examine the processed CTD data during descent via 
interactive plot windows on the display, which could also be initiated from 
other workstations on the network. Additionally, the operator would decide 
where to trip bottles on the up cast, noting this on the console log. The 
PDR and CTD altimeter channel were monitored to insure the bottom depth was 
known at all times.

The rosette distance above the bottom was monitored by the deck watch 
leader using the altimeter, which (together with the lack of ship motion in 
the ice) allowed bottom approaches to within 10 meters.

Bottles would be closed on the up cast by pointing the console trackball 
cursor at a graphic firing control and clicking a button. The data 
acquisition system would respond with the CTD rosette trip data and a pylon 
confirmation message in a window. All tripping attempts were noted on the 
console log. The console operator would then direct the winch operator to 
the next bottle stop. The console operator was also responsible for 
generating the sample log for the cast.

After the last bottle was tripped, the console operator would inform the 
deck watch and the rosette would be brought on deck. Once on deck, the 
console operator would terminate the data acquisition and turn-off the CTD, 
pylon and VCR recording. The VCR tape was filed.



1.6. CTD Data Processing

ODF CTD processing software consists of some 35-odd programs running under 
the Unix operating system. The initial CTD processing program (ctdba) is 
used either in real-time or with existing raw data sets to:

• Convert raw CTD scans into scaled engineering units, and assign the data 
  to logical channels;
• Filter data channels according to specified filtering criteria;
• Apply sensor or instrument-specific response-correction models;
• Provide periodic averages of the channels corresponding to the output 
  time-series interval; and
• Store the output time-series in a CTD-independent format.

Once the CTD data are reduced to a standard-format time-series, they can be 
manipulated in a number of various ways. Channels can be additionally 
filtered. The time-series can be split up into shorter time-series
or pasted together to form longer time-series. A time-series can be 
transformed into a pressure-series, or a different interval time-series. 
Calibration corrections to the series are maintained in separate files and 
are applied whenever the data are accessed.

ODF data acquisition software acquired and processed the CTD data in real-
time, providing calibrated, processed data for interactive plotting and 
reporting during a cast. The 20 FPS data from the CTD were filtered, 
response-corrected and averaged to a 0.5 second time-series. Sensor 
correction and calibration models were applied to pressure, temperature, 
conductivity and 0 2 Rosette trip data were extracted from this time-series 
in response to trip initiation and confirmation signals. The calibrated 0.5 
second time-series data were stored on disk (as were the 20 FPS raw data) 
and were available in real-time for reporting and graphical display. At the 
end of the cast, various consistency and calibration checks were performed, 
and a 2.0 db pressure-series of the down-cast was generated and subsequently 
used for reports and plots.

CTD plots generated automatically at the completion of deployment were 
checked for potential problems. The two PRT temperature sensors were 
compared with the SBE 35 temperature reference and checked for sensor drift. 
The CTD conductivity sensor was monitored by comparing CTD values to check-
sample conductivities and by deep TS comparisons with adjacent stations. The 
CTD dissolved 0 2 sensor was calibrated to check-sample data.

The primary conductivity sensor developed a non-linear pressure hysteresis 
on cast 12/01. For this reason, the secondary PRT and conductivity sensors 
were processed and used for casts 1/01 through 14/01. While on transit to 
station 15, both conductivity sensors were damaged by freezing and had to be 
replaced. The secondary PRT and (new) secondary conductivity sensors were 
used for casts 15101 and 16/01. On some casts, noise in the 0 2 channel was 
evident. In these cases additional filtering was applied to the 0 2 channel 
in the 0.5 second time-series, using a spike-removal filter that replaced 
points exceeding (by a specified multiple of the standard deviation) the 
least-squares polynomial fit of specified order of segments of the data. The 
filtered points were replaced by the filtering polynomial value.

Freezing conductivity sensors during deployment were a problem on two casts 
(13/01, 14/01). This was anticipated and was diagnosed immediately. The cast 
was lowered to about 50 meters (until the sensor responded normally), then 
raised to just-below the surface. The cast was then lowered normally. The 
initial yo-yo to 50 meters was removed from the data set, and the pressure 
calibration model re-applied to the pressure channel.

Operating in ice provided an additional complication to CTD data processing 
due to the lack of package motion initiated by ship-roll (figures 1.6.0 and 
1.6.1). The 36-bottle rosette is a large (2 meter diameter, 2 meter height) 
package that has considerable drag and a noticeable wake. At bottle stops, 
the wake catches up with the package, resulting in anomalous CTD 
temperatures and conductivities in high gradient regions (figure 1.6.2).


Figure 1.6.0: Bottom of cast 7/01. Ship-roll is evident.
Figure 1.6.1: Bottom of cast 14/01. No ship-roll is evident.
Figure 1.6.2: The effect of package wake on downcast and upcast CTD 
              temperature.
Figure 1.6.3: The bottom two rosette trips from figure 1.6.2,
              as a function of elapsed time.


Figures 1.6.2 and 1.6.3 show pronounced spikes at each bottle stop on the 
upcast temperature trace. This effect biased comparisons made between the 
CTD and check samples used to calibrate CTD conductivity. A more realistic 
comparison was obtained by extracting CTD data corresponding to a rosette 
trip five seconds before the actual trip. On casts 15101 and 16/01 the CTD 
temperature was carefully monitored for stability at each bottle stop before 
tripping the bottle.

Another interesting effect was noted on several casts (10/01 through 15/01) 
while descending through the deep isothermal layer of the Canada Basin. When 
the descent rate was decreased to less than 10 M/min, a rise of up to 
0.001°C was observed (figure 1.6.4), proof that this was an artifact.


Figure 1.6.4: Thermal artifact on cast 12/01 produced by slowing the rosette 
              in the deep isothermal layer.


Table 1.6.0 provides a list of all CTD casts requiring special attention.

Table 1.6.0: Tabulation of problem CTD casts.

Cast           Problems                            Solutions
-------------  ----------------------------------  --------------------------
008/01         Winch stop @ 1566M d/c, O2 offset.  Filtered.
012/01         T,C (T2,C2) noise@700-1800 secs     Filtered.
013/01         Frozen conductivity sensors         Filtered, pressure cali-
                                                   bration model reapplied.
014/01         Frozen conductivity sensors         Filtered, pressure cali-
                                                   bration model reapplied.
001/01-014/01  Package wake on up-cast,            Trip time offset -5.0 secs
               bad CTD trip values                                           
014/01-015/01  Winch stop @ 2065M (sea cable)      O2 filtered.
015/01-016/01  New conductivity sensors            New conductivity calibra-
                                                   tion used.



1.7.  CTD Shipboard Calibration Procedures

• ODF CTD #5 was used for all casts.
• A SBE 35 Laboratory-grade reference temperature sensor (#350006) was 
  deployed on the rosette as a cross calibration check for the primary and 
  secondary PRT temperatures.
• Due to the appearance of a non-linear pressure hysteresis in the primary 
  conductivity channel on cast 12/01, the secondary PRT and conductivity 
  sensors were used from all casts.
• CTD conductivity and dissolved O2 were calibrated to in-situ check samples 
  collected during each rosette cast.
• Due to the effects of the rosette package wake at bottle stops, rosette 
  trip data were offset -5.0 seconds for casts 1/01-14/01.
• Both conductivity sensors were replaced prior to cast 015/01 because of 
  damage to the original sensors caused by freezing.


CTD Pressure and Temperature

The final pressure and temperature calibrations will be determined when CTD 
#5 is returned to ODF. Based on the SBE 35 comparisons and the conductivity 
calibration, there were no significant shifts in the CTD pressure or 
temperature.

The primary (serial #15407) and secondary (serial #17534) PRTs both appeared 
to hold their calibration relative to the SBE 35 to within 0.0005°C. 
Figures 1.7.0 and 1.7.1 summarize the comparisons between the SBE 35 
temperature reference and the primary and secondary PRT temperatures.


Figure 1.7.0: Comparison between SBE 35 reference and primary PRT 
              temperatures.
Figure 1.7.1: Comparison between SBE 35 reference and secondary PRT 
              temperatures.


Conductivity

The CTD rosette trip pressure and temperature and the bottle salinity were 
used to calculate a bottle conductivity. Differences between the bottle and 
CTD conductivities were then used to derive a conductivity correction. This 
correction is normally linear for the 3cm conductivity cell employed in the 
Mark III.

Casts 1/01 through 14/01 were calibrated as a group. Since the conductivity 
sensors were replaced prior to cast 15/01, 15101 and 16/01 were calibrated 
as a second group.

For casts 1/01 through 14/01 conductivity differences were fit to CTD 
conductivity for each cast, and the mean of the conductivity correction 
slopes examined (figure 1.7.2):


Figure 1.7.2: Conductivity correction slopes, per station.


No statistically significant change in the conductivity correction slope 
occurred through cast 14/01. Conductivity differences were then fit to CTD 
conductivity for all bottles to determine a mean conductivity correction 
slope (figure 1.7.3):


Figure 1.7.3: Mean conductivity correction slope, stations 1-14.


Since the mean correction slope did not significantly differ from the mean 
of individual slopes, the mean correction slope was applied and individual 
correction offsets fit for each cast. The resulting correction was adjusted 
for minor non-linearities in pressure. Figure 1.7.4 illustrates the 
correction offsets by station after applying the correction slope:


Figure 1.7.4: Conductivity correction offsets, casts 1/01-14/01.


The final form of the conductivity correction for casts 1/01-14/01 is:

G(corr) = G(raw) - 2.25278e - l0P(^2) + 6.7119e - 07P - 0.000251172G(raw) + C(offset)          (1.7.0)

where:

G(corr)   = Corrected conductivity (mmhos/cm);
G(raw)    = Raw sensor conductivity;
P         = Corrected CTD pressure (db); and
C(offset) = Coefficient derived from the fit to bottle conductivity.


Casts 15/01 and 16/01 were determined in the same fashion. The final form of 
the conductivity correction for casts 15/01 and 16/01 is:

G(corr) = (Gra)w + 1 31955e -09P(^2) + -4.1843e - 06P - 0.0298943G(raw) + C(offset)              (1.7.1)


Deep potential temperature-salinity overlays of successive CTD casts were 
then examined for consistency and the corrections fine-tuned.

Figures 1.7.5, 1.7.6 and 1.7.7 summarize the residual differences between 
bottle and CTD salinities after applying the conductivity correction.


Figure 1.7.5: Salinity residual differences after correction, by pressure.


Note that because of extreme temperature and conductivity gradients, and 
rosette package wake effects, there are some large (>0.5 PSU) differences 
between the CTD and bottle salinities. These large gradients typically 
occurred between 50 and 250 meters, and were excluded from the calibration.


Figure 1.7.6: Salinity residual differences after correction, by station.
Figure 1.7.7: Deep salinity residual differences after correction, by 
              station.


3-sigma from the mean residual in Figures 1.7.6 and 1.7.7, or ±0.0021 PSU 
for all salinities and ±0.0014 PSU for deep salinities represents the limit 
of repeatability of the bottle salinities with all sources of variation 
(e.g., Autosal, rosette, operators and samplers) included. This limit agrees 
with station overlays of deep TS. Within a cast (a single salinometer run), 
the precision of bottle salinities appears to exceed 0.001 PSU. The 
precision of the CTD salinities appears to exceed 0.0005 PSU.


CTD Dissolved Oxygen

The CTD dissolved O2 sensor (serial #6-02-07) worked without major problems 
the entire cruise. There were problems fitting the CTD data to check 
samples because of rosette package wake, high gradients and cold 
temperatures. Additionally, the winch was stopped during the downcasts of 
14/01 and 15/01 to examine the wire, which subsequently required filtering 
the CTD O2 channel.

There are a number of problems with the response characteristics of the 
Sensormedics O2 sensor used in the NBIS Mark III CTD, the major ones being 
a secondary thermal response and a sensitivity to profiling velocity. 
Because of these problems, CTD rosette trip data cannot be directly 
calibrated to O2 check samples. Instead, down-cast CTD O2 data are derived 
by matching the up-cast rosette trips along isopycnal surfaces. The 
differences between CTD O2 modeled from these derived values and check 
samples are then minimized using a non-linear least-squares fitting 
procedure. Figures 1.7.8 and 1.7.9 show the residual differences between 
the corrected CTD O2 and the bottle O2 (ml/1) for each station.


Figure 1.7.8: O2 residual differences after correction, by station.
Figure 1.7.9: O2 residual differences (>2000db).


Note that the mean of the differences is not zero, because the O2 values are 
weighted by pressure before fitting. The standard deviations of 0.090 ml/l 
for all oxygens and 0.081 ml/l for deep oxygens are only intended as metrics 
of the goodness of the fits. ODF makes no claims regarding the precision or 
accuracy of CTD dissolved O2 data.

The general form of the ODF O2 conversion equation follows Brown and Morrison 
[Brow78] and Millard [Mi1182], [Owen85]. ODF does not use a digitized O2 
sensor temperature to model the secondary thermal response but instead models 
membrane and sensor temperatures by low-pass filtering the PRT temperature.

In-situ pressure and temperature are filtered to match the sensor response. 
Time-constants for the pressure response r, and two temperature responses 
tau-Ts and tau-Tf are fitting parameters. The sensor current, or O(c) 
gradient is approximated by low-pass filtering 1° O(c) differences. This term 
attempts to correct for reduction of species other than O2 at the cathode. 
The time-constant for this filter, tau(og), is a fitting parameter. Oxygen 
partial-pressure is then calculated: 
                                                      dOc
                                   (c3Pl+c4Tf+c5Ts+c6 ---)
O(pp) = [c1Oc+C2] · fsat(S,T,P) · e                   dt             (1.7.1)

where:

O(pp)       = Dissolved O2 partial-pressure in atmospheres (atm);
O(c)        = Sensor current (µamps);
fsat(S,T,P) = O2 saturation partial-pressure at S,T,P (atm);
S           = Salinity at O2 response-time (PSUs);
T           = Temperature at O2 response-time (°C);
P           = Pressure at O2 response-time (decibars);
Pl          = Low-pass filtered pressure (decibars);
Tf          = Fast low-pass filtered temperature (°C);
Ts          = Slow low-pass filtered temperature (°C);
dOc
---         = Sensor current gradient (µamps/secs).
dt


1.8.  Bottle Sampling

At the end of each rosette deployment water samples were drawn from the 
bottles in the following order:

  •  CFCs;
  •  3He;
  •  O2;
  •  Total C02;
  •  Alkalinity;
  •  HCH;
  •  TOC, TON,

The following samples were drawn in the following approximate order:

  •  Nutrients;
  •  Tritium;
  •  129I;
  •  Salinity;
  •  18O;
  •  Ba;
  •  137Cs.

Note that some properties were subsampled by cast or by station, so the 
actual sequence of samples drawn was modified accordingly.

The correspondence between individual sample containers and the rosette 
bottle from which the sample was drawn was recorded on the sample log for 
the cast. This log also included any comments or anomalous conditions noted 
about the rosette and bottles. One member of the sampling team was 
designated the sample cop, whose sole responsibility was to maintain this 
log and insure that sampling progressed in proper drawing order.

Normal sampling practice included opening the drain valve before opening the 
air vent on the bottle, indicating an air leak if water escaped. This 
observation together with other diagnostic comments (e.g., "lanyard caught 
in lid", "valve left open") that might later prove useful in determining 
sample integrity were routinely noted on the sample log.

Drawing oxygen samples also involved taking the sample draw temperature from 
the bottle. The temperature was noted on the sample log and can sometimes be 
useful in determining leaking or mis-tripped bottles.

Once individual samples had been drawn and properly prepared, they were 
distributed for analysis.


1.9.  Bottle Data Processing

The first stage of bottle data processing consisted of verifying and 
validating individual samples, and checking the sample log (the sample 
inventory) for consistency. Oxygen flask numbers were verified, as each 
flask is individually calibrated. At this stage, bottle tripping problems 
would have been resolved, had there been any. The rosette bottle number was 
the primary identification for all samples taken from the bottle, as well as 
for the CTD data associated with the bottle. All CTD trips were retained 
whether confirmed or not so that they could be used to help resolve bottle 
tripping problems. Additionally, BIO (Bedford) numbers were assigned 
uniquely to each bottle tripped on the cruise. The BIO number was used by 
the tracer groups.

Diagnostic comments from the sample log were then translated into 
preliminary WOCE quality codes, together with appropriate comments. Each 
code indicating a potential problem would be investigated.

The next stage of processing would begin after all the samples for a cast 
had been accounted for. All samples for bottles suspected of leaking were 
checked to see if the properties were consistent with the profile for the 
cast, with adjacent stations and where applicable, with the CTD data. All 
comments from the analysts were examined and turned into appropriate water 
sample codes.

The third stage of processing continued throughout the cruise and later 
until the data set was judged "final". Various property-property plots and 
vertical sections were examined for both consistency within a cast and 
consistency with adjacent stations. In conjunction with this process the 
analysts would review (and sometimes revise) their data as additional 
calibration or diagnostic results became available. Assignment of a WHP 
water sample quality code to an anomalous sample value was typically 
achieved through consensus.

WHP water bottle quality flags were assigned with the following additional 
interpretations:

3 | An air leak large enough to produce an observable effect on a sample is
  | identified by a code of 3 on the bottle and a code of 4 on the oxygen. 
  | (Small air leaks may have no observable effect, or may only affect gas 
  | samples.)
4 | Bottles tripped at other than the intended depth were assigned a code of 
  | 4. There may be no problems with the associated water sample data.
5 | No water sample data reported. This is a representative level derived 
  | from the CTD data for reporting purposes. The sample number should be in 
  | the range of 80-99.

WHP water sample quality flags were assigned using the following criteria:

1 | The sample for this measurement was drawn from a bottle, but the results 
  | of the analysis were not (yet) received.
2 | Acceptable measurement.
3 | Questionable measurement. The data did not fit the station profile or 
  | adjacent station comparisons (or possibly CTD data comparisons). No notes
  | from the analyst indicated a problem. The data could be correct, but are 
  | open to interpretation.
4 | Bad measurement. Does not fit the station profile, adjacent stations or 
  | CTD data. There were analytical notes indicating a problem, but data 
  | values were reported. Sampling and analytical errors were also coded as 
  | 4.
5 | Not reported. There should always be a reason associated with a code of 
  | 5, usually that the sample was lost, contaminated or rendered unusable.
9 | The sample for this measurement was not drawn.

WHP water sample quality flags were assigned to the CTDSAL (CTD salinity) 
parameter as follows:

2 | Acceptable measurement.
3 | Questionable measurement. The data did not fit the bottle data, or there 
  | was a CTD conductivity calibration shift during the cast.
4 | Bad measurement. The CTD data were determined to be unusable for calcu-
  | lating a salinity.
8 | The CTD salinity was derived from the CTD down cast, matched on an
  | isopycnal surface.

WHP water sample quality flags were assigned to the CTDOXY (CTD oxygen) 
parameter as follows:

2 | Acceptable measurement.
4 | Bad measurement. The CTD data were determined to be unusable for calcu-
  | lating a dissolved oxygen concentration.
5 | Not reported. The CTD data could not be reported.
9 | Not sampled. No operational dissolved oxygen sensor was present on this
  | cast.

Note that all CTDOXY values were derived from the down cast data, matched to 
the upcast along isopycnal surfaces.

Table 1.9.0 shows the number of samples drawn and the number of times each 
WHP sample quality flag was assigned for each basic hydrographic property:


Table 1.9.0: Frequency of WHP quality flag assignments.

                          Rosette Samples Stations 001-016

                       Reported        WHP Quality Flag
                        Levels    1   2   3   4   5   8   9
                       --------  --- --- --- --- --- --- ---
              Bottle      481     0  480  1   0   0   0   0
              CTD Salt    481     0  481  0   0   0   0   0
              CTD02       481     0  481  0   0   0   0   0
              Nitrite     450     0  449  1   0   0   0  31
              Nitrate     450     0  449  1   0   0   0  31
              Oxygen      442     0  426 13   3   4   0  35
              Phosphate   450     0  447  3   0   0   0  31
              Silicate    450     0  449  1   0   0   0  31
              Salinity    479     0  476  3   0   0   0   2


Additionally, all WHP quality code comments are presented in Appendix A.


1.10. Salinity Analysis

Salinity samples were drawn into 200 ml Kimax high alumina borosilicate 
bottles after 3 rinses, and were sealed with custom-made plastic insert 
thimbles and Nalgene screw caps. This assembly provides very low container 
dissolution and sample evaporation. Salinity was determined after a box of 
samples had equilibrated to laboratory temperature, usually within 8-12 
hours of collection. The draw time and equilibration time, as well as per-
sample analysis time and temperature were logged.

A Guildline Autosal Model 8400A salinometer (55-654) located in a 
temperature-controlled laboratory was used to measure salinities. The 
salinometer was modified by ODF and contained interfaces for computer aided 
measurement. A computer (PC) prompted the analyst for control functions 
(changing sample, flushing) while it made continuous measurements and logged 
results.

The salinometer was standardized for each cast with IAPSO Standard Seawater 
(SSW) Batch P-125, using at least one fresh vial per cast. The estimated 
accuracy of bottle salinities run at sea is usually better than 0.002 PSU 
relative to the particular Standard Seawater batch used. PSS-78 salinity 
[UNES81] was then calculated for each sample from the measured conductivity 
ratios, and the results merged with the hydrographic database.

479 salinity measurements were made and 35 vials of standard water were 
used. Various statistics pertaining to each run are summarized in Table 
1.10.0. The temperature stability of the laboratory used to make the 
measurements was very good, ranging from 22.6 to 24.8°C. The salinometer 
bath temperature was maintained at 24°C. The salinities were used to 
calibrate the CTD conductivity sensor.


Autosal log starting 25/09/1997
Expedition: JOIS LEG 4
Ship:       CCGS LOUIS S. ST. LAURENT
Salinometer serial number 55-654


Table 1.10.0: Arctic 97/JOIS Leg 4 per-box salinometer log.

       Box Nbr  Equ       Start   End Start  End  Bath Worm  Start  End  Std 
 St Cs Nbr Smp  Hrs  Date  Time  Time Air    Air  Temp Batch Sby    Sby  Dial   Drift   OPR
--- -- --- --- ----  ---- -----  ---- -----  ---- ---- ----  ----  ----  ---  --------  ---
  1  1  J   6  18.9  2509  2042  2112  23.4  23.5  24  P125  6507  6508  569  -9.00000  CM
  2  1  J   8  18.1  2509  2113  2138  23.5  23.8  24  P125  6507  6508  569  -9.00000  CM
  3  1  J  15  17.3  2509  2200  2331  23.7  24.2  24  P125  6508  6544  569  +0.00006  SR
  4  1  C  27  17.4  2609  0108  0246  23.5  24.0  24  P125  6502  6501  563  +0.00006  SR
  5  1  R  34  21.1  2609  1426  1622  23.3  24.2  24  P125  6501  6491  563  -0.00000  SR
  6  1  E  32  20.6  2609  1809  1915  23.6  24.3  24  P125  6502  6503  563  +0.00000  CM
  7  1  J  35  42.9  2609  1917  2043  24.3  24.7  24  P125  6502  6502  563  -0.00002  SR
  8  1  C  36  19.5  2709  0031  0206  23.6  24.0  24  P125  6502  6502  563  +0.00003  SR
  9  1  R  36  20.8  2709  1545  1711  22.7  23.8  24  P125  6503  6503  563  +0.00000  SR
 10  1  J  36  18.8  2709  1809  1937  23.3  23.8  24  P125  6503  6502  563  +0.00001  SR
 11  1  E  36  14.9  2709  1938  2102  23.8  24.3  24  P125  6502  6502  563  +0.00008  SR
 12  1  J  36  12.5  2809  1436  1615  22.6  24.0  24  P125  6497  6496  554  -0.00003  SR
 13  1  E  36  24.8  0110  2127  2249  23.8  24.4  24  P125  6500  6500  558  -9.00000  SR
 13  2  C   5 999.0  0110  2250  2314  24.4  24.7  24  P125  6500  6499  558  +0.00004  SR
 14  1  C  36  16.2  0210  2011  2230  23.4  24.3  24  P125  6501  6501  558  -9.00000  SR
 11 91  A   7 137.8  0210  2230  2257  24.3  24.8  24  P125  6501  6500  558  +0.00007  SR
 15  1  C  36  38.2  1410  1825  2002  23.1  22.6  24  P125  6497  6497  547  -9.00000  SR
112  1  A   3 104.1  1410  2004  2020  22.6  22.1  24  P125  6497  6496  547  +0.00001  SR
 16  1  E  29  25.0  1610  2014  2125  22.2  22.5  24  P125  6497  6497  547  +0.00001  SR


1.11. Oxygen Analysis

Samples were collected for dissolved oxygen analyses soon after the rosette 
sampler was brought on board and after CFC and helium were drawn. Nominal 
125 ml volume-calibrated iodine flasks were rinsed twice with minimal 
agitation, then filled via a drawing tube and allowed to overflow for at 
least 3 flask volumes. The sample temperature was measured with a small 
platinum resistance thermometer embedded in the drawing tube. Draw 
temperatures are useful in detecting possible bad trips even as samples are 
being drawn. Reagents were added to fix the oxygen before stoppering. The 
flasks were shaken twice; immediately after drawing, and then again after 20 
minutes, to assure thorough dispersion of the MnO(OH) 2 precipitate. The 
samples were analyzed within 4 hours of collection.

Dissolved oxygen analyses were performed with an ODF-designed automated 
oxygen titrator using photometric end-point detection based on the 
absorption of 365 nm wavelength ultra-violet light. Thiosulfate was 
dispensed by a Dosimat 665 buret driver fitted with a 1.0 ml buret. The 
apparatus is controlled by a PC running ODF software. ODF uses a whole-
bottle modified-Winkler titration following the technique of Carpenter 
[Carp65] with modifications by Culberson et al. [Culb91], but with higher 
concentrations of potassium iodate standard (approximately 0.012N) and 
thiosulfate solution (50 gm/1). Standard solutions prepared from pre-weighed 
potassium iodate crystals were run at the beginning of each session of 
analyses, which typically included from 1 to 3 stations. Several standards 
were made up during the cruise and compared to assure that the results were 
reproducible, and to preclude the possibility of a weighing error. 
Reagent/distilled water blanks were determined to account for oxidizing or 
reducing materials in the reagents. No preservative was added to the 
thiosulfate.

The auto-titrator generally performed well, although titrator computer-
related glitches caused 7 samples to be lost. The titrator computer also 
did not maintain the proper date.

Blanks, and thiosulfate normalities corrected to 20°C, calculated from each 
standardization, were plotted versus time, and were reviewed for possible 
problems. New thiosulfate normalities were recalculated after the blanks had 
been smoothed. These normalities were then smoothed, and the oxygen data 
were recalculated.

Oxygens were converted from milliliters per liter to micromoles per kilogram 
using the in-situ temperature. Ideally, for whole-bottle titrations, the 
conversion temperature should be the temperature of the water issuing from 
the bottle spigot. The sample temperatures were measured at the time the 
samples were drawn from the bottle, but were not used by the reporting 
software in the conversion from milliliters per liter to micromoles per 
kilogram.

Oxygen flasks were calibrated gravimetrically with degassed deionized water 
(DIW) to determine flask volumes at ODF's chemistry laboratory. This is done 
once before using flasks for the first time and periodically thereafter when 
a suspect bottle volume is detected. All volumetric glassware used in 
preparing standards is calibrated as well as the 10 ml Dosimat buret used to 
dispense standard iodate solution.

Iodate standards are pre-weighed in ODF's chemistry laboratory to a nominal 
weight of 0.44xx grams and the exact normality is calculated at sea. 
Potassium iodate (KlO3) is obtained from Johnson Matthey Chemical Co. and is 
reported by the suppliers to be > 99.4% pure. All other reagents are 
"reagent grade" and are tested for levels of oxidizing and reducing 
impurities prior to use.

442 oxygen measurements were made. The temperature of the laboratory used 
for the analyses ranged from 26° to 29°C, and temperature stability was 
generally poor.


1.12. Nutrient Analysis

Nutrient samples were drawn into dual 8 ml high density polyethylene, narrow 
mouth, screw-capped centrifuge tubes which were rinsed three times before 
filling. The tubes were rinsed with 1.2N HCL before each filling. 
Standardizations were performed at the beginning and end of each group of 
analyses (one cast, up to 36 samples) with a set of an intermediate 
concentration standard prepared in low-nutrient seawater for each run from 
secondary standards. The secondary standards were prepared aboard ship by 
dilution from dry, pre-weighed primary standards. Sets of 6-7 different 
concentrations of shipboard standards were analyzed periodically to 
determine the deviation from linearity as a function of concentration for 
each nutrient. All nutrient concentrations encountered on this cruise were 
in their respective linear ranges.

Nutrient analyses (phosphate, silicate, nitrate and nitrite) were performed 
on a 4 channel Technicon AutoAnalyzer II borrowed from IOS, generally 
within one hour of the cast. Occasionally some samples were refrigerated at 
4°C for a maximum of 4 hours. The methods used are described by Gordon et 
al. [Atla71], [Hage72], [Gord92]. The colorimeter output from each of the 
four channels were recorded on a strip-chart recorder and logged manually.

Silicate is analyzed using the technique of Armstrong et al. [Arms67]. 
Ammonium molybdate is added to a seawater sample to produce silicomolybdic 
acid which is then reduced to silicomolybdous acid (a blue compound) 
following the addition of stannous chloride. Tartaric acid is added to 
impede P04 color interference. The sample is passed through a 50 mm 
flowcell and the absorbance measured at 660nm.

Modifications of the Armstrong et al. [Arms67] techniques for nitrate and 
nitrite analysis are also used. The seawater sample for nitrate analysis is 
passed through a cadmium column where the nitrate is reduced to nitrite. 
Sulfanilamide is introduced, reacting with the nitrite, then N-(1-
naphthyl)ethylenediamine dihydrochloride which couples to form a red azo 
dye. The reaction product is then passed through a 50 mm flowcell and the 
absorbance measured at 550 nm. The same technique is employed for nitrite 
analysis, except the cadmium column is not present.

Phosphate is analyzed using a modification of the Bernhardt and Wilhelms 
[Bern67] technique. An acidic solution of ammonium molybdate is added to 
the sample to produce phosphomolybdic acid, then reduced to 
phosphomolybdous acid (a blue compound) following the addition of 
dihydrazine sulfate. The reaction product is heated to 50°C to enhance 
color development, then passed through a 50 mm flowcell and the absorbance 
measured at 820 nm.

Nutrients, reported in micromoles per kilogram, were converted from 
micromoles per liter by dividing by sample density calculated at zero 
pressure, in-situ salinity, and an assumed laboratory temperature of 25°C.

Na2SiF6, the silicate primary standard, is obtained from Aesar, a division 
of Johnson Matthey Chemical Co., and is reported by the supplier to be >98% 
pure. Primary standards for nitrate (KNO3), nitrite (NaNO2), and phosphate 
(KH2PO4) are also obtained from Johnson Matthey Chemical Co. and the 
supplier reports purifies of 99.999%, 97%, and 99.999%, respectively.

450 nutrient analyses were performed. No major problems were encountered 
with the measurements. The efficiency of the cadmium column used for nitrate 
was monitored throughout the cruise and ranged from 99.5-100.0%. The 
temperature of the laboratory used for the analyses ranged from 26° to 29°C, 
and temperature stability was generally poor. Attempts to improve the 
stability using oscillating fans met with little success. The laboratory 
temperature was monitored and recorded.



TABULATED DATA

The following data are tabulated:

A WOCE Hydrographic Program format (Joyce et al., 1994) summary ("*.SUM") 
file was produced for the expedition.  In it, station positions were taken 
from a GPS receiver in a small van near the CTD winch.  Times (all in 
Universal Time) are accurate within about one minute. Due to problems with 
the ship's depth sounder, the reported depths are calculated from corrected 
maximum CTD pressure and calculated CTD density profiles, plus the altimeter 
height above bottom.

CTD and bottle data for each station are tabulated in WOCE Hydrographic 
Program formats (Joyce et al., 1994): hydrographic data  in a "*SEA" file 
and CTD data in ".CTD" files.  The single exception to the format and content 
rules for the bottle data is that two data indices appear in the report.  The 
WOCE recommendations, followed by the lead group on the bottle data, are for 
indexing of samples via a hierarchy of expedition/station/cast/bottle, where 
the bottle number refers to the Niskin bottle number for the sample.  The 
second index is known as a "Bedford number" and is a unique, one-time-only 
identifier assigned to each bottle closed during an expedition, and also 
attached to any samples drawn from it.  These are included in the "*.SEA" 
file to assist co-investigators' registration of their sample data.

Depths, in meters, are calculated using the Saunders-Mantyla step-wise 
application of the hydrostatic equation.

Temperatures reported are ITS90.  

Practical salinities (PSS78) are used throughout.  Neither the symbol ‰ nor 
"psu" are used for PSS78 salinities.

Dissolved oxygen concentrations, all from bottle samples, are listed in units 
of µmol/kg, as per WOCE Hydrographic Program practice.  Although for the 
oxygen titration methodology employed here the correct temperature to use for 
conversion from the original units of ml/L to µmol/kg is the temperature of 
the water as it issues from the Niskin bottle spigot, and although that 
temperature was measured for every water sample, software limitations make it 
necessary to use in situ water temperature for the conversions.  This 
introduces only a very small error. 

Nutrient values are reported in µmol/kg, as per WOCE Hydrographic Program 
recommendations.

Potential temperatures are calculated from Fofonoff's (1977) computational 
method, based upon Bryden's (1973) results.  Densities, expressed in sigma-
notation (sigma-p = rho-p - 1000 kg/m3), are calculated at the sea surface, 
and 1000, 2000, and 3000 decibars, from the International Equation of State 
(EOS80; see UNESCO, 1981).  For example, rho-3 is the in situ density in 
kg/m3 that the water would have if moved adiabatically to the depth where the 
pressure is 3000 db (= 30 MPa), and sigma-3 is this value less 1000 Kg/m3.



OUTCOME  OF THIS PROGRAM

The Canada Basin section was a central focus of the JOIS Leg 4 science plan 
but an ancillary program from the perspective of SHEBA.  Planning letters 
indicated that 72 hours of dedicated wire time were tentatively allocated to 
the Section.  With much time lost to logistics difficulties at the beginning 
of the expedition (see narrative), it was expected that the Section would of 
necessity be carried out at an at-least reduced level.  This reduction took 
place, as measured by the final count of 15 stations along track, reduced 
from ca. 23 in the original plan over this distance, with ≈23 hours of wire 
time used.  A different and more encouraging perspective is afforded by the 
data.  The shelf-slope-basin transition was well measured, with the principal 
reduction in stations there caused more by the combination of problems with 
the depth sounder with a steep slope than any limitations placed by the ship 
or SHEBA.  Station spacing over the basin was to have been 18-20 miles, but 
section plots and other data representations suggest that lateral variability 
in the deep basin domain was low, and that the section program suffered 
little as a result of the reduced lateral coverage.  The primary objective of 
linking boundary and interior measurements from a single expedition aimed at 
producing reference-quality measurements was well-realized.  New and 
occasionally subtle features were seen that could not be gleaned easily from 
comparing boundary and interior data from two expeditions.  The JOIS Leg 4 
Canada Basin section will also help to set the tone for future work.  The 
expedition can be regarded as a success, with much owed to the departments 
and agencies which supported this work on short notice.





References

Ande71
    Anderson G.C., compiler (1971)  Oxygen Analysis, Marine Technician's 
    Handbook, Scripps Institution of Oceanography Reference No. 71-8, Sea 
    Grant Publication No. 9.

Arms67.
    Armstrong, F.A.J., Steams, C.R., and Strickland, J.D.H., "The 
    measurement of upwelling and subsequent biological processes by means of 
    the Technicon Autoanalyzer and associated equipment," Deep-Sea Research, 
    14, pp. 381-389 (1967).

Atla7l.
    Atlas, E.L., Hager, S.W., Gordon, L.I., and Park, P.K., "A Practical 
    Manual for Use of the Technicon AutoAnalyzer® in Seawater Nutrient 
    Analyses Revised," Technical Report 215, Reference 71-22, p. 49, Oregon 
    State University, Department of Oceanography (1971).

Bern67.
    Bernhardt, H. and Wilhelms, A., "The continuous determination of low 
    level iron, soluble phosphate and total phosphate with the 
    AutoAnalyzer," Technicon Symposia, I, pp. 385-389 (1967).

Brow78.
    Brown, N. L. and Morrison, G.K., "WHOI/Brown conductivity, temperature 
    and depth microprofiler' Technical Report No. 78-23, Woods Hole 
    Oceanographic Institution (1978).

Carp65.
    Carpenter, J.H., "The Chesapeake Bay Institute technique for the 
    Winkler dissolved oxygen method," Limnology and Oceanography, 10, pp. 
    141-143 (1965).

Culb9l.
    Culberson, C.H. and Williams, R.T., et al., "A comparison of methods 
    for the determination of dissolved oxygen in seawater," Report WHPO 91-
    2, WOCE Hydrographic Programme Office (Aug 1991).

Gord92.
    Gordon, L.I., Jennings, J.C., Jr., Ross, A.A., and Krest, J.M., "A 
    suggested Protocol for Continuous Flow Automated Analysis of Seawater 
    Nutrients in the WOCE Hydrographic Program and the Joint Global Ocean 
    Fluxes Study," Grp. Tech Rpt 92-1, OSU College of Oceanography Descr. 
    Chem Oc. (1992).

Hage72.
    Hager, S.W., Atlas, E.L., Gordon, L.D., Mantyla, A.W., and Park, P.K.,
    "A comparison at sea of manual and autoanalyzer analyses of 
    phosphate, nitrate, and silicate," Limnology and Oceanography, 17, pp. 
    931-937 (1972).

Mill82.
    Millard, R.C., Jr., "CTD calibration and data processing techniques at 
    WHOI using the practical salinity scale," Proc. Int. STD Conference and 
    Workshop, p. 19, Mar. Tech. Soc., La Jolla, Ca. (1982).

Owen85.
    Owens, W.B. and Millard, R.C., Jr., "A new algorithm for CTD oxygen 
    calibration," Journ. of Am. Meteorological Soc., 15, p. 621 (1985).

SBE97.
    Sea-Bird Electronics, Inc., SBE, "SBE 35 Reference Temperature Sensor 
    Operating Manual," Version 35.001, April 16, 1997 (1997).

UNES81.
    UNESCO, "Background papers and supporting data on the Practical 
    Salinity Scale, 1978," UNESCO Technical Papers in Marine Science, No. 
    37, p. 144 (1981).




2.  Helium, Tritium and 18O

Sample Collection

Samples for the analysis of helium, tritium and 180 were collected from the 
10 L Niskin bottles. The strategy was to sample the entire water column. 216 
samples for combined helium and tritium analysis, 207 samples for combined 
tritium and 180 analysis, and 362 samples for 180 analysis were collected. 
Water samples for helium and tritium analysis were collected in 40 ml copper 
tubes sealed by pinch off tools. Water samples for tritium and 180 analysis 
were collected in 1 L glass bottles. Water samples for 180 analysis were 
collected in 30 ml glass bottles.

Sample Analysis

Samples for helium and tritium analysis from the copper tubes and the 1 L 
glass bottles will be measured in the Noble Gas Laboratory of the Lamont-
Doherty Earth Observatory of Columbia University according to the procedure 
described in detail by Ludin et al. (submitted). 180 samples from the 1 L 
glass bottles will be analyzed mass spectrometrically in the Stable Isotope 
Laboratory of the Lamont-Doherty Earth Observatory of Columbia University, 
and from the 30 ml glass bottles by K. Falkner of Oregon State University.



References

Ludin, A., R. Weppernig, G. Bönisch, P. Schlosser Mass spectrometric helium 
    isotope and tritium measurements. Manuscript for AGU monograph 'Tracer 
    Oceanography'. Submitted.




DATA PROCESSING NOTES

Date        Contact    Data Type  Summary
----------  ---------  ---------  -------------------------------------------
2010-09-01  Fields, J  BTL        Copied from CARINA collection 
            This bottle file was part of the CARINA collection compiled by 
            Bob Key. 

2010-11-19  Muus, D    CTD/BTL    data online 
            Notes on Louis St-Laurent cruise JOIS 97 Leg IV Expocode 
            18SN19970924 101119/dm
      
            1.  CARINA bottle data file posted Sept 1, 2010. (Date Stamp 
                20081215PRINUNIVRMK) 
            2.  Header notes modified Sept 15, 2010: Chief Scientist: "Jim 
                Swift" vs "F. McLaughlin, K. Faulkner" Faulkner misspelling 
                corrected to Falkner.
            3.  CARINA bottle file missing TIME, CTDSAL, CTDOXY. Some SALNTY 
                appear to be CTDSAL.  Changed bottle numbers on CARINA file 
                Station 13 Casts 1 & 2 to match ODF bottle numbers. (e.g. 
                Cast 1 changed from 5-40 to 1-36, bottom-top.)
            4.  ODF bottle file(dated Dec 16, 1997) has slightly different 
                nutrients, CFCs, TCARBN and ALKALI. No TCARBN or ALKALI 
                flags. 
            5.  Assume ODF file has best CTD, oxygen and nutrient data and 
                CARINA has best CFCs, TCARBN and ALKALI.
            6.  Merged CARINA CFCs, TCARBN and ALKALI into ODF bottle file.
            7.  ODF/TIC (C. Mattson) Preliminary Cruise Report says departure 
                Tuktoyaktuk 18 Sep 1997.  ODF unsigned 25 page Preliminary 
                Cruise Report says departure Tuktoyaktuk 20 Sep 1997. CARINA 
                file used EXPOCODE 18SN19970924. (Date of first station)
                Used Expocode 18SN19970924 since it has been previously used.
            8.  Made WOCE and Exchange format CTD files from ODF files dated 
                Oct 17, 1997
            9.  New WOCE and Exchange format bottle and CTD files posted on 
                website Nov 19, 2010.
 
2010-11-24  Kappa, J   CrsRpt     Website Updated  New PDF version online
            I just put a preliminary pdf cruise report for jois97 in the 
            JOIS97_18SN19970924 directory.

2010-12-10  Muus, D    CTD/SUM    Website Update  CTD Exchange & sum files online 
            Notes on Louis St-Laurent cruise JOIS 97 Leg IV   Expocode  
            18SN19970924     101119/dm

            1. CARINA bottle data file posted Sept 1, 2010. (Date Stamp  
               20081215PRINUNIVRMK)
            2. Header notes modified Sept 15, 2010:
               Chief Scientist: "Jim Swift" vs "F. McLaughlin, K. Faulkner"
               Faulkner misspelling corrected to Falkner.
            3. CARINA bottle file missing TIME, CTDSAL, CTDOXY. Some SALNTY 
                 appear to be CTDSAL.
               Changed bottle numbers on CARINA file Station 13 Casts 1 & 2 
                 to match ODF bottle numbers.
                 (e.g. Cast 1 changed from 5-40 to 1-36, bottom-top.)
            4. ODF bottle file(dated Dec 16, 1997) has slightly different  
               nutrients, CFCs, TCARBN and ALKALI. No TCARBN or ALKALI flags.
            5. Assume ODF file has best CTD, oxygen and nutrient data and 
               CARINA has best CFCs, TCARBN and ALKALI.
            6. Merged CARINA CFCs, TCARBN and ALKALI into ODF bottle file.
            7. ODF/TIC (C. Mattson) Preliminary Cruise Report says departure  
                 Tuktoyaktuk 18 Sep 1997.
               ODF unsigned 25 page Preliminary Cruise Report says departure  
                 Tuktoyaktuk 20 Sep 1997.
               CARINA file used EXPOCODE 18SN19970924.  (Date of first 
                 station)
               Used Expocode 18SN19970924 since it has been previously used.
            8. Made WOCE and Exchange format CTD files from ODF files dated 
               Oct 17, 1997.
            9. New WOCE and Exchange format bottle and CTD files posted on 
               website Nov 19, 2010.

2014-03-12  Kappa, J   CrsRpt   Website Updated  New TXT version online
            I've placed a new TXT version of the cruise report: 
              JOIS97_18SN19970924do.txt
            into the directory: 
              http://cchdo.ucsd.edu/data/co2clivar/arctic/JOIS97/JOIS97_18SN19970924/ .
            It includes all the reports provided by the cruise PIs, summary 
            pages and CCHDO data processing notes.
