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CRUISE REPORT: ATAS1-3
(Updated DEC 2011)

   




Highlights



                                     Cruise Summary Information


           Section Designation  ATAS1                     ATAS2                   ATAS3
        Expedition designation  316N198212_1              316N198212_2            316N198301
              Chief Scientists  Jorge L. Sarmiento,       Claes G.H. Rooth,       Taro Takahashi,
                                  Princeton Univ.           Univ. of Miami          LDGO
                         Dates  1982 DEC 01 -             1982 DEC 29 -           1983 JAN 30 - 
                                  1982 DEC 22               1983 JAN 24             1983 FEB 18
                          Ship  R/V Knorr
                 Ports of call  San Juan, Puerto Rico -   Belém, Brazil           Dakar, Senegal
                                  Belém, Brazil -           Dakar, Senegal -        Recife, Brazil

                                             27° 51.4' N
         Geographic Boundaries  66° 2.1' W                17° 28.4' W
                                              8° 38' S

                      Stations  30                        39                      38
  Floats and drifters deployed  0
Moorings deployed or recovered  0


                                     Recent Contact Information:

                                         Jorge L. Sarmiento 
                                        Princeton University
                  306A Sayre Hall • M44 Guyot Hall • Princeton • New Jersey • 08544
                          Phone: (609) 258-6585 • Email: jls@princeton.edu

                                          Claes G.H. Rooth
                                  RSMAS/MPO • University of Miami
                            4600 Rickenbacker Causeway • Miami, FL 33149 
               Phone: 305-361-4162 • Fax: 305-361-4696 • Email: crooth@rsmas.miami.edu

                                           Taro Takahashi 
                                  Lamont-Doherty Earth Observatory
                 101Comer • 61 Route 9W - PO Box 1000 • Palisades • NY • 10964-8000
              Phone: 845-365-8537 • Fax: 845-365-8155 • Email: taka@ldeo.columbia.edu





                                  TRANSIENT TRACERS IN THE OCEAN


                                     TROPICAL ATLANTIC  STUDY

                                1 December 1982 - 18 February 1983

                           Shipboard Physical and Chemical Data Report





                                                                          Data Report Prepared by

                                                  Physical & Chemical Oceanographic Data Facility
                                                              Scripps Institution of Oceanography
                                                              University of California, San Diego

                                                                                         May 1986










Sponsored by

  National Science Foundation                                             SIO Reference No. 86-16
  Grant OCE 81-17844                                                   PACODF Publication No. 222





                                  Transient Tracers in the Ocean
                                     Tropical Atlantic Studies


                                    Itinerary of the RV Knorr

                         Depart                   Arrive

                         Leg I    San Juan, Puerto Rico    Belém, Brazil
                         1 December 1982          22 December 1982
                Leg II   Belém, Brazil            Dakar, Senegal
                         29 December 1982         24 January 1983
                Leg III  Dakar, Senegal           Recife, Brazil
                         30 January 1983          18 February 1983




INTRODUCTION

In this report are published the shipboard hydrographic and radon data taken 
during the Tropical Atlantic Study of the Transient Tracers in the Ocean 
program (TTO-TAS). Hydrographic data were taken by the Physical and Chemical 
Oceanographic Data Facility (PACODF) of Scripps Institution of Oceanography. 
The radon data included in the final section of this report were taken by 
William Smethie of Lamont-Doherty Geological Observatory.

The field work was carried out aboard RV KNORR, operated by Woods Hole 
Oceanographic Institution (WHOI), on an expedition of 3 legs. The expedition 
began at San Juan Puerto Rico, leaving port on 1 December 1982, and 
terminated on 18 February 1983, in Recife Brazil. During the expedition many 
of the Geochemical Ocean Section Study (GEOSECS) stations taken in 1972 were 
reoccupied, and many of the parameters measured during the GEOSECS program 
were sampled again, some by the same personnel, some even with the same 
equipment, and of course, on the same ship. The chief scientists, most of 
whom were heavily involved in the GEOSECS program, prepared brief narratives 
for each leg which were published as introductions to the preliminary leg 
reports, and which are reproduced in the following section of this final 
report.

Many of the potential users of this report are familiar with GEOSECS data 
reports, the GEOSECS Atlas series [1], and the units and parameters used 
therein. While the tabular data format appearing here is similar to that 
found in GEOSECS publications, potential temperature and density-related 
parameters (sigma theta, 2, 4) published in this report will not be directly 
comparable with the same GOSECS parameters. The specific gravity equations of 
Cox et al. [2] and compressibility of Ekman [3] were used throughout the 
GEOSECS program to calculate sigma theta and sigma 4. In the early stages of 
planning TTO, it was decided to use the new International Equation of State 
[4] from which absolute densities may be calculated rather than specific 
gravities. The sigma quantities in this report, as in the TTO North Atlantic 
Study report, are therefore potential densities in units of kilograms/cubic 
meter, from which 1000 has been subtracted.

Potential temperatures in the GEOSECS data were calculated according to 
Helland-Hansen [5]. In this report that parameter has been computed using 
Fofonoff's integration of Bryden's adiabatic temperature gradient equation 
[6]. The same routine is used to compute the temperature of water moved 
adiabatically to 2000 or 4000 decibars, for the subsequent calculations of 
sigma 2 or sigma 4.

A comparison of various calculations of sigmas, including the Knudsen 
equations [7], and potential temperatures for NAS Station 6 was published in 
Volume I, TTO-AS Preliminary Hydrographic Data Report. Typical differences 
are as follows:



       P      T       S    POT T   SIG 0   SIG 2   SIG 4   Sources
     ----  ------  ------  ------  ------  ------  ------  --------
        8  21.509  36.420  21.507  25.437  33.824  41.853  F-B  IES
                           21.507  25.455  33.857  41.879  H-H  COX
                                   25.452  33.854  41.874    KNUD
     2493   3.408  34.967   3.201  27.840  36.972  45.698  F-B  IES
                            3.197  27.876  37.034  45.759  H-H  COX
                                   27.862  37.020  45.744    KNUD
     5316   2.238  34.877   1.737  27.894  37.107  45.908  F-B  IES
                            1.727  27.927  37.168  45.968  H-H  COX
                                   27.916  37.156  45.957    KNUD


Rosette cast pressure and temperature data given in this report were normally 
taken from the corrected CTD output at the time the bottles were tripped. 
Reversing thermometers provided pressure and temperature for Gerard and most 
shallow radon casts. Salinity has been calculated according to the equations 
of the Practical Salinity Scale of 1978 [8] from either CTD conductivity, 
temperature, and pressure, or conductivity ratio determined from bottle 
samples analyzed in duplicate with a Guildline Model 8400 laboratory 
salinometer. Dissolved oxygen was determined by a modified Winkler titration 
[9]. Nutrients (silicate, phosphate nitrate and nitrite) were analyzed using 
a modified Technicon AutoAnalyzer and the methodologies employed during 
GEOSECS [1]. Alkalinity and Total CO2 were determined by potentiometric acid 
titration with hardware developed for the GEOSECS Indian Ocean Expedition 
[10] and the equations of Bradshaw and Brewer [11].

Casts taken during the expedition can generally be categorized in two types, 
small and large volume. Small volume casts employed a PACODF-designed 
multisampler based on a General Oceanics rosette pylon. On the multisampler 
were mounted 24 PVC sampling bottles of 10 liters volume, a Neil. Brown Mark 
III CTD modified by PACODF, and a pinger. On occasional stations 30 liter 
Niskin bottles were deployed serially on the hydro wire for collection of 
surface radon samples.

Large volume stations included the normal small volume sample acquisition 
plus the collection of samples for shorebased analysis of radiocarbon, Ra-
228, Kr 85, and infrequently, Ar-39. These samples were collected in 270 
liter stainless steel Gerard barrels deployed on the ship's trawl wire. 
Usually, 9 barrels were used on each cast. A 10 liter Niskin bottle was 
mounted on the outside of each Gerard barrel and was linked to the Gerard 
closure mechanism so that the Gerard could not close without tripping the 
Niskin bottle as well.

The original intent of this system was to provide a verification of the 
Gerard tripping depths via the reversing thermometers mounted on the Niskin 
bottle, and by comparison of salinities taken from both samplers. For the TTO 
program a decision was made to draw the standard rosette samples from the 
Niskins used on large volume casts rather than interpolate property values 
from the rosette casts as was done during the GEOSECS program.

Following the protocol established during the GEOSECS program, all samples 
were given a sample number which is equal to the cast X 100 plus the bottle 
number. For convenience, sampling bottles were numbered as follows:

                  1-24   10 liter rosette bottle
                 25-36   30 liter rosette bottle
                 40-47   10 liter bottle mounted on Gerard barrel
                 50-65    5 liter rosette bottle
                 70-78   30 liter bottle deployed on hydra wire
                 85-97  270 liter Gerard barrel

Throughout the data report alphabetic characters may be found in the tabular 
data. These characters have the following meaning:

    D  A salinity value, normally from a bottle sample has been taken 
       from CTD records.
    H  A pressure or temperature value has been calculated from thermo- 
       metric sources rather than from the CTD as is normally the case 
       on rosette casts.
    U  A data value is suspect, although no obvious reason has been found.

Listings of the subroutines used in the calculation of various parameters are 
included in Appendix I.

The hydrographic and CTD work was supported by the National Science 
Foundation, Division of Ocean Science Section, Grant #OCE 81-17844 to 
Physical and Chemical Oceanographic Data Facility, Scripps Institution of 
Oceanography.

                                                     Robert T. Williams
                                                     Acting Project Director
                                                     PACODF




REFERENCES

[1]  A.E. Bainbridge, GEOSECS Atlantic Expedition Volume 1, Hydrographic 
          Data, National Science Foundation (1981) 038-000-00491-3.
     A.E. Bainbridge, GEOSECS Atlantic Expedition Volume 2, Sections and 
          Profiles, National Science Foundation (1980) 038-000-00435-2.
     W.S. Broecker, D.W. Spencer, H. Craig, GEOSECS Pacific Expedition Volume 
          3, Hydrographic Data, National Science Foundation (1982) 
          038-000-00503-1.
     H. Craig, W.S. Broecker, D.W. Spencer, GEOSECS Pacific Expedition Volume 
          4 Sections and Profiles, National Science Foundation (1981) 
          038-000-00496-4.
     R.F. Weiss, W.S. Broecker, H. Craig D.W. Spencer GEOSECS Indian Ocean 
          Expedition Volume 5, Hydrographic Data, National Science Foundation 
          (1983) 03-000-00525-1.
     D.W. Spencer W.S. Broecker, H. Craig, R.F. Weiss, GEOSECS Indian Ocean 
          Expedition Volume 6, Sections and Profiles, National Science 
          Foundation (1982) 038-000-00515-4.
     H.G. Ostlund, H. Craig W.S. Broecker, D.W. Spencer, GEOSECS Atlantic 
          Pacific, and Indian Oceans Expedition Volume 7, Shorebased Data, 
          National Science Foundation (In press).

[2]  R.A. Cox, N.J. McCartney, and F. Culkin, The specific gravity/salinity/
          temperature relationship in natural seawater, Deep Sea Research 17 
          (1970) 679-689.

[3]  V.W. Ekman, Die Zusammendruckbarkeit des Meerwassers nebst einigen 
          Werten fur Wasser und Quecksilber, Publications de Circonstance Conseil 
          Permanent international pour l'exploration de la Mer 43 (1908) 1-47.

[4]  F.J. Millero, C.T. Chen, A. Bradshaw, and K. Schleicher, A new high 
          pressure equation of state for seawater, Deep Sea Research 2 (1980).
    
[5]  B. Helland-Hansen, The Ocean Waters Intern. Rev. Gee. Hydrobiol. 
          Hydrogr., Suppl. to Bd. III, Ser.1, H.2 (1912) 1-84.
    
[6]  N.P. Fofonoff, Computation of potential temperature of seawater for an 
          arbitrary reference pressure, Deep Sea Research 24 (1980) 489-491.
    
[7]  N. Knudsen, C. Forch, and S.P.L. Sorensen, Berichte uber die 
          Konstantenbestimmungen zur Auftellung der Hydrographischen Tabellen. 
          Vgl. Danske Videnskab. Selskabe, Skrifter, Naturvidenskab. math, Afdel. 
          XII 1 (1902) 2-151.
    
[8]  E.L. Lewis, The Practical Salinity Scale 1978 and its antecedents, IEEE 
          J. of Oceanic Eng. OE-5 (1980) 3-8.
    
[9]  J.H. Carpenter, The Chesapeake Bay Institute technique for the Winkler 
          dissolved oxygen method, Limnology and Oceanography 10 (1965) 141-143.
    
[10] D.L. Bos, R.T. Williams, History and development of the GEOSECS 
          alkalinity titration system, Workshop on Oceanic CO2 Standardization, 
          November 30-December 1, 1979, Carbon Dioxide Effects Research and 
          Assessment Program, CONF-7911173, U.S. Department of Energy (1982) 
          42-59.

[11] ALL. Bradshaw, P.O. Brewer, DBK. Schaefer, R.T. Williams, Measurements 
          of total carbon dioxide and alkalinity by potentiometric titration in 
          the GEOSECS Program, Earth and Planetary Science Letters 55 (1981) 
          99-115.
    



Leg I
1 December - 22 December 1982


1.  General Description

Leg 1 of the Tropical Atlantic Study was carried out during the period 
December 1, 1982 to December 22, 1982, between the ports of San Juan, Puerto 
Rico and Belém, Brazil. The leg consisted essentially of four sections. The 
first section took us southeast across the Caribbean Basin. The second 
section vent east-northeast across the deep western basin of the Atlantic up 
to the Mid-Ocean ridge. The third section went south across the North 
Equatorial Current salinity front. The fourth part of the leg took us onto 
the Brazilian continental shelf and then south and into the main channel of 
the Amazon estuary.

The KNORR departed San Juan on time after several days of sustained effort 
by the PACODF group and others to set the ship up for the expedition. Our 
Brazilian Navy observer, Lt. Jair Xavier da Silva arrived just in time for 
our departure.

We had been alerted to the fact that there had been a considerable spill of 
C-14 on the ship on the leg prior to ours. Gate Ostlund was able to complete 
a swab test while we were still in San Juan that showed that C-14 activities 
were high and that the contamination was far more extensive than we had been 
led to believe. As a consequence, we swabbed the entire laboratory area with 
dilute acid and took the C-14 extractors apart in order to bathe them in a 
dilute acid bath. The scientific crew did a superb job, particularly Tim 
Field, who had to strip down and reassemble the extractors and then do a 
series of blank runs to verify that we had achieved our goals. The blank 
runs and a subsequent swab test, carried out during a short stop in 
Barbados, showed that the contamination problem was apparently taken care of 
by our efforts. This experience demonstrated the great value and importance 
of the Ostlund swabbing procedure.

The first station was carried out on the day following our departure from San 
Juan. We had the misfortune to lose a sampling rosette during this station. 
The station was completed with a hydrocast while the spare rosette was 
assembled for the next station. All subsequent work was completed without any 
further technical problems. The PACODF group did an excellent job with able 
assistance from four people who had come along for the Amazon work from 
Harvard University, MIT and Princeton University. We were able to complete 
most of the work that had been planned except for some reduction of the track 
that had to be done due to the slow cruising speed against the winds and 
currents during the first part of the leg. The excellent support of the 
officers and crew of the KNORR is gratefully acknowledged, as is the 
generosity of the Brazilian Government in allowing us to work in their 
territorial waters. Lt. Jair Xavier da Silva made an excellent shipmate who 
showed a great deal of interest in all that was going on around him. Our 
results are going to be of far greater benefit because o the opportunity we 
had to carry our sections onto the Brazilian continental shelf and into the 
Amazon estuary.


2.  Highlights of Preliminary Results

The fresh surface mixed layer waters of the Caribbean and East Atlantic were 
shown to have high silica content, consistent with a strong Amazon River 
component. We carried out extra nutrient sampling in this water in order to 
trace its distribution in greater detail. This work should prove of great 
interest, particularly as it was carried out in conjunction with a detailed 
study of the Amazon estuary.

The structure of the Subtropical Underwater salinity maximum and the Central 
Waters below that were consistent with previous studies of these water 
masses. The detailed sampling of our station configuration was supplemented 
by XBTs taken approximately every 30 to 50 kilometers. We observed multiple 
staircase structures at they bas of the Central Waters. The salinity front in 
the North Equatorial Current was successfully crossed on the third section of 
the leg. The freon measurements throughout this depth range showed the 
structure that one would expect from the tritium observations of the 1972 
period. The greater detail of this survey will permit a far more careful 
study of the structure of the transient tracer fields.

The Antarctic Intermediate water was detected at a depth of 600-1000 meters. 
The freon signal in this water was at background. The core of the Antarctic 
Intermediate Water strengthened perceptibly as we vent towards the mouth. 
Just below this was the upper North Atlantic Deep Water. This water type had 
a strong freon signal, consistent with the maximum observed at the same 
depths in tritium on previous cruises. The freon at this depth was observed 
even as we neared the equator.

We were very impressed to find a weak freon signal in the deeper North 
Atlantic Deep Water Western Boundary Current even as far south as our section 
off Brazil at approximately 5 to 10 degree. north. This clearly demonstrates 
that the tracer signals which have been observed in the North American Basin 
off the Blake-Bahama Outer Ridge as well as north of the Greater Antilles 
have managed to advect out of the Basin and move quite far to the south.

There was no clear evidence of freon in the Antarctic Bottom Water during the 
preliminary shipboard analysis.

The Amazon estuary phase of the cruise wag completed without any major 
difficulties other than the usual navigational problems encountered when 
working in such a small area without any shorebased navigational aids. The 
conditions found during our study were quite different from those of an 
earlier study in that nutrient removal from river water was occurring at a 
much higher salinity than previously observed. This was apparently due to the 
high turbidity encountered on this expedition.

                                                     Jorge L. Sarmiento
                                                     Peter Rhines
                                                     William N. Smethie, Jr.




Leg II
29 December 1982 - 24 January 1983

1.  General Description

The objectives for this leg of the TAS Expedition were:

[1] To fill in a major data gap in the upper water column tritium 
    distribution in the central subtropical and tropical North Atlantic.
[2] To provide a first systematic set of freon concentration profiles in the 
    same region.
[3] To illuminate abyssal circulation and exchange conditions by C-14 and 
    Ra-228 distribution studies in the interhemispheric deep water passage in 
    the West Atlantic, and along the eastern slope of the Mid-ocean ridge 
    north of the Vema Passage.
[4] To provide two general chemical sections crossing the southerly boundary 
    of the Central Atlantic salt tongue in the Central Waters and of the 
    expected shadow zone edge for the wind driven circulation in the main 
    thermocline.
[5] To reach into the region of influence of the NW African upwelling zone in 
    order to help assess its significance as an input zone for trace 
    substance contamination in the Atlantic main thermocline.

The KNORR departed Belém in fair weather on the assigned day, hurried on in 
fact, by the imminent docking of a giant bulk grain carrier at the silo dock 
where we had been tied up. Fairly strong head winds and adverse swell 
conditions during the first two weeks held our rate of steaming between 
stations to barely above eight knots, causing a decision to truncate the NW 
corner of the originally planned track. Time was later recovered under light 
wind conditions, allowing a track diversion in a more favorable direction 
perpendicular to a steep section of continental rise off Cape Blanc, and an 
enhanced station density there, compared to the original plan. Fortuitously, 
the data indicates that these track revisions probably lead to a significant 
enhancement of the value of the final leg segment in towards Africa.

A total of forty Rosette stations were occupied, fifteen of them accompanied 
by large volume samples from twenty-six Gerard casts. Thirteen radon casts 
were also made, in general at the large volume stations (see map).

Technically, the whole operation vent quite smoothly in spite of severe 
resource limitations both in personnel and in computer equipment in the CTD 
operations. This can be ascribed not only to the usual competent performance 
of the SIO-PACODF Group, but also, in a large degree, to the help rendered 
on the deck watches by the CalTech students, Don Piepgras and Mary Stordal. 
Without it the workload on the PACODF Group would have been quite excessive.

The value of the satellite communication link to home bases for the clearing 
up of minor technical problems was repeatedly demonstrated.

Finally, the excellent support of the officers and crew of the KNORR must be 
acknowledged as an essential element in the smooth progress of the 
scientific work.


2.  Some Highlights of the Preliminary Results.

One can consider this leg as being composed of three sections, viz. the 
Western Basin transect, Stations 55-62; the Eastern Ridge Slope Transect, 
Stations 63-79 and the Shadow Zone Transect, Stations 80-94.

During the Western Basin transect, our attention was captured by the strong 
baroclinicity along the Continental Rise, even just at the equator. Water as 
cold as θ = 0.9°C was found between the equator and a latitude of about 4°N, in 
a depth range of 4300 to 4400m. A distinct reversal in baroclinicity was 
observed at θ = 1.6 to 1.7°C, indicating that the maximum inflow velocity 
occurs in that temperature range.

The coldest potential temperature observed in the Eastern Basin Transect 
(just north of the Vema fracture zone) was 1.745°C. A slight rise in 
dissolved oxygen concentration below a depth of 4000m was observed all along 
the Rise section. It remains to be considered to what degree a westward 
intensified bottom circulation and leakage through the ridge may be 
contributing to this phenomenon. Comparison with the Eastern Basin GEOSECS 
data, as well. as with the final section of this leg, show that in the 
central and eastern parts of this Basin, the deepest layers show oxygen 
concentration decrease, rather than increase.

The freon data on the first two sections of this leg indicate a minimum 
concentration at the AAIW salinity minimum, with a distinct increase below 
it. The letter is associated with the relatively high salinity North 
Atlantic Central water. The deep freon signal was close to the detection 
limit everywhere except at the first few stations in the western boundary 
region. The intermediate freon minimum, on the other hand, gradually 
vanished along with the disappearance of the distinct AAIW signature.

A large anticyclonic thermocline eddy was encountered on the final section, 
at Station 84. Although it was impossible to devote the time required for a 
mesoscale survey, it was clear from the Station 84 data that this was an 
object comparable to the main eddy observed by Armi during Leg 2 of the 
TTO-NAS Expedition in 1981. The central density (Sigma 2) was almost 
identical, and the vertical extent comparable to that observed before. AOU 
values were slightly higher in the core bottle samples. Most exciting was 
the observation of an enormous freon signal, with a ratio of concentrations 
of F-11 and 12 suggestive of quite recent origin.

It is tempting, albeit impossible of proof, to speculate on the possible 
identity of the two eddies observed with an eighteen month time differential. 
The mean southward drift rate of about 1 cm/sec is certainly not 
unreasonable. More promising, however, is the prospect that between the 
various tracer signatures, we might discern a definite source for the eddy, 
and perhaps an approximate age.

The main points of interest in the final stations are two viz, the upwelling 
influence and the effect of bottom processes on the Cape Verde Plateau. As 
expected, we observed strong baroclinicity in the upper several hundred 
meters, as well as strong lateral intrusion signatures. A clear pCO2 maximum 
generated in the bottom boundary layer on the plateau was found, and 
surprisingly, a pronounced freon signature as well. The latter was quite 
anomalous in its composition strongly dominated by F-11. The observation of 
this contamination both at stations 93 and 94, and at the latter both in the 
bottom sample, and at a level about 120m up suggests a substantial source. A 
special bottom boundary layer experiment on the Cape Verde Plateau, with 
freon and radon profile mapping along with physical turbulence observations, 
seems to offer very exciting prospects.

                                                     Claus G.H. Rooth
                                                     Robert M. Key





Leg III
30 January 1983 - 18 February 1983

The RV KNORR departed Dakar, Senegal at 1300 local time on January 31, 1983, 
for Leg 3 of Tropical Atlantic Study, the Transient Tracers in the Oceans 
Project. The major objectives of this leg were to collect the hydrographic 
and atmospheric chemistry data along the following three transects:

A) an E-W transect between the African coast and the 28 degree W meridian 
   along the 9°30'N parallel in the eastern basin of the North Atlantic 
   Oceans
B) a N-S transect between 9°30'N and 8°S latitudes along the 28 degree W 
   meridian across the equator; and
C) an E-W transect between the 28 degree W meridian and the coast of Brazil 
   along the 8 degree S parallel.

The first six stations (Stations 95 through 100) define the E-W transect 
across the Kane Gap (approx. 4660 meters deep), which is the major conduit 
for the	 deep waters of the Sierra Leone Basin to the south and the Gambia 
Abyssal Basin the north. No benthic boundary layer characteristic of fast 
water movements along the sea floor was observed.

The E-W transect of the eastern Basin is defined by Stations 100 through 104. 
German Meteor Stations 11-505, which was occupied in 1981, was reoccupied at 
Station 103 at 9°30'N and 26°00' W, and 9 samples each for C-14, Ra-228 and 
tritium were collected in addition to a standard 22-bottle rosette cast.

The N-S transect along the 28 degree W meridian across the equator is defined 
by Stations 104 through 123. Stations 104 through 111 are located in the 
eastern Basin, Stations 112 through 114 are located in the vicinity of St. 
Paul's fracture zone, and Stations 115 through 123 are located in the western 
basin. In the depth range of 60 to 100 meters, high salinity tongues of the 
Subtropical Underwater originating in the northern and southern temperate 
latitudes were observed. The potential temperature (θ)-salinity (S) 
relationships observed at these stations are shown in Figure 1. The salinity 
values for Station 123 are to be read according to the scale shown, and those 
for all other stations are offset by 0.05 ‰ salinity each in order of 
decreasing station number. At Station 106 a salinity inversion is observed at 
a depth of about 400 meters (θ = 9.5°C), and a weak salinity signal is also 
seen at Station 107 at a similar depth and temperature. These features are 
characteristic of the interleaving of South and North Atlantic Central Waters 
originating off Africa. At greater depths of about 800 meters and potential 
temperature of about 5°C, the Antarctic Intermediate Water (AAIW) is 
observed. The largest horizontal gradients in the AAIW are observed in the 
southward transect of the Eastern Basin (Figure 2). The temperature at the 
salinity minimum for AAIW decreases from about 5.9°C at 9°30'N (Station 104) 
to 4.6°C a 00°30'S (Station 113), and the salinity value at the minimum 
decreases from 34.7 ‰ to 34.5 ‰ in this same distance. This boundary is the 
result of intensification of AAIW toward its source region as well as 
recirculation of these waters in the North Atlantic. Between the salinity 
minimum for the AAIW and the underlying salinity maximum which identifies the 
Upper North Atlantic Deep Water (UNADW), the temperature stays more or less 
constant. However, beginning at Station 109 an increase in potential 
temperature with depth is observed. This is due to the fact that the 
intermediate waters have cooled so that they are colder than the underlying 
UNADW.

Properties of UNADW were found to have the greatest variability in the 
Eastern Basin (Figure 3) with temperature and salinity increasing from 3.4 to 
3.9°C and 34.95 to 34.97 ‰, respectively, along 9°30'N from the African coast 
to 28 degrees W. The most saline UNADW, 34.98 ‰, was observed at Station 114 
and corresponded to minimum silicate (17.4 µM/kg) and maximum oxygen (248 
µM/kg) . UNADW properties approaching these values were also observed at 
Station 130 near Brazil.

Beneath the UNADW, oxygen maximum associated with Middle and Lower North 
Atlantic Deep Waters were observed. These features were better developed in 
the Western Basin than the Eastern Basin and appeared most clearly at 
Stations 120-123. Here the oxygen content of the MNADW and LNADW was 252 and 
257 µM/kg respectively, and the oxygen minimum separating these waters was 
243 salinity for this depth zone (2400 to 3000 meters) and temperature range 
(2.0 to 2.7°C) is nearly constant, and a small salinity inversion develops at 
stations 120-123 between the oxygen minimum and the LNAW. This salinity 
feature occurs at a depth of about 2700 meters and a potential temperature of 
2.6°. It is probably due to differing flow paths and rates of the over and 
underlying water masses. Below 2°C, the θ - S relationship is linear, 
representing a mixing line between the Antarctic Deep Water (AADW) with the 
overlying NADW. The highest silica concentration observed in the near bottom 
samples at these stations is about 120 µM/kg, indicating a strong influence 
of the AADW.

The atmospheric chemistry was also investigated during the N-S transect 
across the equator. It has been observed that the atmospheric concentration 
of CO2 and freons both decrease dramatically south of the Intertropical 
Convergence Zone (ITCZ) located between 5°30'N and 2°30'S. Atmospheric 
krypton samples were also collected during this transect. The air-sea gas 
exchange rate was investigated using Rn-222, a natural radioactive gas 
produced by decay of Ra-226 present in seawater. Within the equatorial 
doldrum zone, where the sea surface was like a mirror due to little or no 
wind, an extremely low gas exchange rate of 0.6 meters/day (compared to the 
global mean of 2.8 ± 0.3 meters/ day) was observed.

The E-W transect along the 8°S parallel is defined by Stations 123 through 
132 located between 28 degrees W and the coast of Brazil. The observed θ - S 
relationship at these stations are shown in Figure 4. It is observed that the 
AAIW freshens westward to the Brazilian coast, and that the 0 - S curve 
between the NADW salinity maximum and the AABW becomes increasingly smooth to 
the Brazilian coast. The constant salinity zone located at temperatures 
between 2.0 and 2.7°C is observed only at the easternmost stations (Station 
123, 126 and 127 in Figure 2). At three stations located over the continental 
slope of Brazil (Stations 129 through 131), strong freon signals were 
observed at a depth range of 1600 to 1900 meters (θ = 3.8 C and salinity 
34.97 ‰ oxygen 240 µM/kg and silica = 18.1 µM/kg). The observed high freon 
concentrations indicate the this water is young (i.e. formed within the last 
25 years or less), and the silica data indicate that this water is of the 
northern origin. The high oxygen concentration also supports a young age of 
this water. Thus, it is speculated that this water may represent a 
continuation of the southward flowing Western Boundary Undercurrent of the 
northern origin.

The expedition was completed on February 18, 1982 at Recife, Brazil.

                                                     Taro Takahashi
                                                     Curtis Collins





Figure 1: The potential temperature-salinity relationships observed at 
          Stations 106 through 123 along the 28°W meridian. Stations 106 
          through 111 are located in the eastern Basin, and Stations 112 
          through 123 are in the western Basin. Note that the salinity scale 
          indicated applies only to Station 123, and the earlier stations are 
          offset by 0.05 ‰ each in order of the decreasing station number.

Figure 2: Observed Properties of AAIW (quantities on right are plotted as 
          dashed lines)

Figure 3: Observed Properties of UNADW (quantities on right ore plotted as 
          dashed lines)

Figure 4: The potential temperature-salinity relationships observed at 
          Stations 123 through 132 along the 8°S parallel in the western 
          Basin. Note that the salinity scale indicated applies only to 
          Station 132, and the earlier stations are offset by 0.05 ‰ each 
          in order o the decreasing station number.
 



SCIENTIFIC PROGRAMS

                                                                        Total 
Participating              Principal                                    Samples 
Institutions               Investigators      Scientific Programs       Collected
-------------------------  -----------------  ------------------------  ---------
Lamont-Doherty Geological  W.S. Broecker,     222Rn                         381
Observatory of Columbia    T.-H. Peng and     85Kr                          134
University                 W.M. Smethie, Jr.  and Modeling
                           T. Takahashi       pCO2                         1178
                                              and carbonate chemistry       603

Princeton University       J.L. Sarmiento     Modeling of tracers  
                           J.L. Sarmiento,    228Ra                          437
                           R.M. Key           226Ra                         485
                           R.F. Stallard      Amazon River Chemistry  

Scripps Institution of     R.F. Weiss         Chlorofluorocarbons          2282
Oceanography               C.D. Keeling       Total CO2                     184


Physical & Chemical        R.T. Williams      CTD  
Oceanographic Data                            Salinity                     3723
Facility                                      Oxygen                       2934
                                              Nutrients                    2833
                                              Alkalinity and Total CO2     1765
                                              Large volume sampling  
                                              14C extractions  

University of Bern         J.H. Oeschger      39Ar                           54

University of Miami        H.G. Ostlund       3H                           1950
                                              14C                           436

Woods Hole Oceanographic   W.J. Jenkins       3H                           1950
Institution                                   3He                           476
                           C. Measures        Be/Se                          51

California Technological   D. Piepgras        Nd                             39
Institute  
      
Harvard University         S. Wotsy           N2O and                        78
                                              CH4  






LIST OF PARTICIPANTS

Leg I

Ship's Captain        Emerson Hiller

Scientists-in-Charge  Jorge L. Sarmiento, Chief Scientist, Princeton University
                      William M. Smethie, Jr., Lamont-Doherty Geological Observatory
                      Peter Rhines, Woods Hole Oceanographic Institution
                      Lt. Jair Xavier Da Silva, Brazilian Observer

Harvard University    Warren A. Kaplan 
                      Richard G. Porter

Lamont-Doherty        Owen W. Anderson 
Geological            David W. Chipman 
Observatory           Andrew L. Herczeg

Massachusetts         Barry C. Grant
Institute of 
Technology

Princeton University  Frank O. Bryan
                      Robert P. Stallard

Scripps Institution   John L. Bullister
of Oceanography       Frederick A. Van Woy

Scripps Institution   Marie C. Beaupre
of Oceanography       David L. Bos
Physical & Chemical   Carol B. Conway
Oceanographic Data    James P. Costello
Facility              Timothy J. Field
                      Walter A. Richter
                      Edward J. Slater
                      James A. Wells
                      Robert T. Williams





Leg II

Ship's Captain  Emerson Hiller
  
Scientists-in-Charge  Claes G.H. Rooth, Chief Scientist, University of Miami
                      Robert M. Key, Princeton University
                      Lt. Jair Xavier Da Silva, Brazilian Observer
  
California Institute  Donald J. Piepgras
of Technology         Mary C. Stordal

  
Lamont-Doherty        Owen W. Anderson
Geological            Susan E. Trumbore
Observatory           Richard H. Wanninkhof  

Princeton University  Mitsuhiro Kawase
  
Scripps Institution   John L. Bullister
of Oceanography       Mark J. Warner

Scripps Institution   Marie C. Beaupre
of Oceanography       David L. Bos
Physical & Chemical   Carol B. Conway
Oceanographic Data    Timothy J. Field
Facility              Mary C. Johnson
                      Douglas M. Masten
                      Carl W. Mattson
                      David A. Muus
                      James A. Wells






Leg III

Ship's Captain        Emerson Hiller
  
Scientists-in-Charge  Taro Takahashi, Chief Scientist, Lamont-Doherty Geological Observatory
                      Curtis Collins, Woods Hole Oceanographic Institution
                      Lt. Jair Xavier Da Silva, Brazilian Observer
  
California Institute  Mary C. Stordal
of Technology 
  
Lament-Doherty        John G. Goddard
Geological            Guy G. Mathieu
Observatory           Susan E. Trumbore
                      Richard H. Wanninkhof
                      Steven D. Warren

New York University   Tyler Volk
  
National Oceanic &    Richard H. Gammon
Atmospheric 
Administration 
  
Princeton University  Sallye Gorlick
                      G.W. Kent Moore
  
Scripps Institution   Frederick A. Van Woy
of Oceanography 
  
Scripps Institution   Carol B. Conway
of Oceanography       James P. Costello
Physical & Chemical   Timothy J. Field
Oceanographic Data    Douglas M. Masten
Facility              Carl W. Mattson
                      David A. Muus
                      Ronald G. Patrick
                      Paul R. Sweet
                      James A. Wells









CCHDO DATA PROCESSING NOTES


Event Date  Person       Date Type   Summary 
----------  -----------  ----------  ----------------------------------------------------------
2006-04-12  Muus, Dave   CTD/BTL     temp/sal/oxy/nuts/co2/trit/ ctd (some bad sals eliminated) 
            Notes on reformatting TTO TAS 
            Leg 1 Rosette Bottle and CTD data.
            TTO - Transient Tracers in the Ocean
            TAS - Tropical Atlantic Study
            Leg 1 RV KNORR Dec 1-22, 1982
            EXPOCODE 316N198212_1
            1.  Basic bottle data (Temperature, Salinity, Oxygen, Nutrients) 
                from Kristin Sanborn odf@ucsd.edu:/spc/1/odf0-
                archive/235_TTO-TAS/tto-tas 

                See file: whprptas

                CO2 and tritium data from Sarilee Anderson/Joe Reid: 
                tas.c14.orig.Z were merged into the ODF data.

                No LVS (Gerard Barrel) data were included at this time.

            2.  CTD data downloaded from NODC Jan 10, 2006.

                ocldb1136925012.19600.CTD.csv.gz

                Many CTD salinity values were obviously bad and were deleted.  
                Joe Reid's CTD data has the same salinity problem. No CTD is 
                available from ODF. I do not know if the bad salinity data was 
                in the final PACODF data.


