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CRUISE REPORT: SAVE3
(Updated APR 2011)



HIGHLIGHTS
                          Cruise Summary Information

          WOCE Section Designation  SAVE3
Expedition designation (ExpoCodes)  316N19880128
                   Chief Scientist  William J. Jenkins/WHOI
                Co-Chief Scientist  Donald B. Olson/UM
                             Dates  1988 JAN 28  -  1988 MAR 7 
                              Ship  R/V Knorr
                     Ports of call  Rio de Janeiro, Brazil -  
                                    Abidjan, Ivory Coast

                                                   4° 53.1' N
              Geographic Boundaries  41° 23.3' W                   1° 3.4' E
                                                   30° 1.9" S

                           Stations  65
       Floats and drifters deployed  0
     Moorings deployed or recovered  0


                     Chief Scientist's Contact Information

                              William J. Jenkins
                      Woods Hole Oceanographic Institution
              266 Woods Hole Rd. • MS# 08 • Woods Hole, Ma. 02543
        Phone: 508 289 2554 • Fax: 508 457 2193 • Email: wjenkins@whoi.edu

                                Donald B. Olson
University of Miami • RSMAS/MPO • 4600 Rickenbacker Causeway • Miami, FL 33149
   Phone:  305-361-4074 • Fax:  305-361-4696 • E-mail:  dolson@rsmas.miami.edu





              South Atlantic Ventilation Experiment (SAVE) Leg 3

                  Shipboard Chemical and Physical Data Report

                                  PRELIMINARY

                           29 January - 7 March 1988

                                   R/V Knorr


                           Data Report Prepared by:

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

                                  June 1988




Sponsored by
National Science Foundation
Grant OCE-86 13330                                    ODF Publication No. 226





INTRODUCTION
(Donald B. Olson and William Jenkins)

The third leg of the South Atlantic Ventilation Experiment (SAVE) sailed from 
Rio de Janeiro, Brazil on January 28, 1988 on a course across the South 
Atlantic to a point just short of the Walvis Ridge at 30°S (Figure 1) where 
the line turned north through the Angola Basin, across the equator and into 
Abidjan, Ivory Coast. This set of sections provides a line across the 
beginning of the Brazil Current and the northern side of the South Atlantic 
subtropical gyre, then northwards through the cyclonic circulation in the 
eastern subtropical basin and the equatorial domain. The latter section 
repeats the 1983 AJAX section (AJAX, 1985).

A total of 65 stations were occupied during this leg, which included 67 
rosette casts and 60 Gerard casts. Difficulties were encountered with the new 
Gerard Barrels initially due to their requisite "break-in" period. Additional 
difficulties arose which were ultimately linked to excessive "whip-lash" 
action at the end of the trawl wire; a problem eventually remedied by 
augmenting the end weight. 3112 samples were analyzed for salinity, 2389 for 
oxygen and 2288 for nutrients. In addition, a 114 XBT profiles were obtained 
(drops made in between stations) and 71 "underway" surface samples were 
obtained for salinity, oxygen, nutrients, ΣCO2 and pCO2 determinations. 
Auxiliary sampling on the cruise included particulate samples, trace metal 
efforts and limited samples of phytoplankton near the equator for geological 
purposes.

The discussion begins with the eastward section outward from the South 
American coast. The section is nearly parallel to the CATO expedition's 
northern line taken in 1972 (Reid et al., 1977) across the western boundary 
region and therefore provides a high quality comparative cross section. The 
SAVE 3 section also provides comparison with two GEOSECS stations taken just 
north and south of the line.

The section from the Brazilian coast out into the central gyre crosses the 
Brazil Current near its formation region. The near surface southward boundary 
current flow based on direct measurement by Evans and Signorini (1985) has a 
transport of 6X106m3/s above 400 m with a northward flow in the Antarctic 
Intermediate Water (AAIW) below this level. The baroclinic field on the SAVE 
3 section supports a similar transport above the 400 m level but suggest on a 
property basis that the flow is more complicated in the sense that the 
salinity minimum associated with the AAIW is stronger offshore beyond the 
extent of the Evans and Signorini (1985) section. The baroclinic shear 
reverses offshore suggesting a northward flow of similar magnitude a few 
hundred kilometers off the coast. In general the water mass properties show a 
rather confused picture of alternating northern and southern origin waters 
through the intermediate layers near the coast. These variations are most 
prominent in the oxygen signal although they also show in the nutrients and 
salinity on density surfaces.

The deep water complexes (i.e. North Atlantic Deep Water [NADW] and modified 
Circum-polar Deep Waters [CDW]) dominate the water column between 1000 and 
3500 dbars. The most striking contrast between southern and northern waters 
is seen in the silica distribution, which shows the northern (low silica) 
waters hugging the boundary, while the upper CDW influence increases 500 km 
seaward. The NADW complex appears as a series of property extrema embedded 
between this intermediate depth tongue and the Antarctic Bottom Water AABW 
below. The NADW is capped by a potential temperature and salinity maxima 
centered at 1700 dbars along the Brazil Coast. This feature is above the 
silicate minimum associated with Labrador Sea Water and the salinity maximum 
of the Upper NADW proper. The oxygen maximum of the Middle NADW is found even 
deeper just above the rapid change in stratification separating these 
northern source waters from the (AABW). The core of the AABW is shifted 
further seaward and is found on deeper isobaths than at the sill to the south 
in the Vema Passage (Hogg et al., 1982). There is a transition to more 
southern influence in deep waters on the offshore portion of the section as 
the line crosses the longitude of the Rio Grande Rise. This tendency is seen 
as a truncation of the temperature maximum and rapid freshening at the σ2 = 
36.84 level.

The section to the Mid Ocean Ridge was fairly uneventful with the exception 
of an unexpected seamount (the "Olson" seamount based on the P.I. who 
inadvertently placed a station on it) which leads to a discontinuity in the 
sampling of the deep waters. On a more serious note there was time to 
complete enhanced sampling in the AAIW and ABW for Krypton and Argon (Kr 85, 
Ar 39). This increased sample density for these trace gasses and better 
resolution in the vertical for Radium and C14 partially made up for the 
decreased sample density on SAVE 2 which resulted from the loss of Gerrard 
barrels on the first leg of the program. The SAVE program includes some of 
the highest quality CO2 system sampling available to date in the world's 
oceans with the SIO, Weiss underway system and the Lamont in situ work. 
Samples to back calibrate earlier estimates were taken near GEOSECS stations 
with replicate samples drawn for repeat analysis following the original 
protocol specified by Keeling.

East of the Mid Ocean Ridge we increased XBT sampling frequency to monitor 
for anomalies of Agulhas origin in terms of rings (Olson and Evans, 1986; 
McCartney, per. comm.). Based on the depth of the 10°C isotherm on the 
section no ring related perturbations where found despite eternal and dogged 
vigilance on the part of our crack XBT and underway team. This conclusion can 
be tested in terms of existing satellite data based on GEOSAT altimeter 
(Brown and Evans, 1988; Gordon and Haxby, 1988).

The edge of the Subtropical Gyre in the eastern basin of the South Atlantic 
is marked by a frontal zone which has a strong baroclinic signature around 
20°S but an in situ front in terms of gas (O2 and freon) concentration 
approximately two degrees farther to the north (18°S). This latter feature 
separates the fairly well ventilated waters of the subtropical gyre from the 
oxygen minimum in the upper layers of the cyclonic circulation in the Angola 
Basin. The intercomparison of transient gas concentrations based on 
chlorofluoromethane (freon) measurements on AJAX and SAVE (Warner and Weiss, 
per. comm.) suggest significant measurable changes in the cross frontal and 
vertical extent of these tracers.

The edge of the Subtropical Gyre in the South Atlantic in the eastern basin 
is coincident with top to bottom gradients in water mass properties. The 
change is more gradual in the deeper layers which are dominated by a NADW 
source along the equator (Romanche fracture zone). There are however changes 
which suggest a weak secondary exchange across the Mid Ocean Ridge near 20°S 
and modification of oxygen and nutrient profiles due perhaps to interaction 
with the Congo fan. Again, these signals while obvious in the tradition 
tracer fields, i.e. temperature, salinity, oxygen and nutrients; also show up 
in the trace metal field (Measures, per. comm.). Similar conclusions 
concerning a secondary source of properties from the western basin and a 
detailed picture of the possible flow regime in the Angola basin can be found 
in Speer (1986). The additional tracer information in the deep waters as part 
of SAVE 2 & 3 will provide further constraints on the processes in this 
basin.

The Leg 3 line across the equator along with those taken on the previous SAVE 
efforts provide a detailed picture of the distribution of water mass 
properties along the equator. Station spacing was reduced in proximity of the 
equator in order to resolve possible deep equatorial jets. These features 
were first described in the Indian Ocean by Luyten and Swallow (1976) and 
have since been identified as a feature of the deep equatorial circulation in 
all three oceans (Eriksen, 1982). Recent theoretical studies and numerical 
model runs by Kawase (1987) has suggested some of the deep along equator flow 
may result from the introduction of deep waters from the western boundary 
layer. The vertical structure on the equator in the SAVE data set is 
consistent with deep jets but the strongest water mass signals are shifted 
off the equator. The strongest NADW signals in terms of oxygen, salinity and 
chlorofluoromethanes occur in the southern hemisphere along X°S. The maximum 
oxygen signal occurs at 1900 m in what is traditionally noted as the Middle 
NADW. In contrast there is a tongue of chlorofluoromethane bearing fluid 
centered at 1600 m depth at the upper portion of the Labrador Sea Water. This 
is the continuation of the flow first described by Weiss et al. (1985) near 
the equator. One puzzle concerning this transient tracer distribution is that 
the chlorofluoromethanes are found south of the equator in the SAVE 1 and 3 
sections but is found north of the equator in the eastward-most SAVE 2 line.




REFERENCES


AJAX 1985. Physical, chemical and in situ CTD data from the AJAX Expedition 
    in the South Atlantic Ocean. SIO Ref. 85-24, TAMU Ref. 85-4-D., 275 pp.

Brown, O.B., R.H. Evans and D.B. Olson. 1988. Fronts and boundary currents. A 
    comparison between JR and altimeter observations. SARI Meeting Report

Eriksen, C.C. 1982. Geostrophic equatorial deep jets. J. Mar. Res., 40, 
    (Suppl.), 143-157.

Evans, D.L. and S.S. Signorini 1985. Vertical structure of the Brazil Current 
    Nature, 315, 48-50.

Gordon, A.L. and W. Haxby. 1988 South Atlantic Problems: An altimeter view. 
    SARI Meeting Report.

Hogg, N., P. Biscaye, W. Gardner and W. Schmitz 1982. On the transport and 
    modification of Antarctic Bottom Water in the Vema Channel J. Mar. Res., 
    40, supplement, 231-263.

Kawase, M. 1987. Establishment of deep ocean circulation by deep-water 
    production. J. Phys. Oceanogr., 17, 2294-2317.

Luyten, J.R., and J.C. Swallow. 1976. Equatorial undercurrents. Deep Sea 
    Res., 23, 999-1001.

Olson, D.B. and R. H. Evans. 1986. Rings of the Agulhas Current. Deep Sea 
    Res., 33, 27-42.

Reid, J.L., W.D. Nowlin, and W.C. Patzert 1977. On the characteristics and 
    circulation of the Southwestern Atlantic Ocean J. Phys. Oceanogr., 7, 
    62-91.

Speer, K.G. 1985. Property distributions and circulation in the Angola Basin. 
    M.S. thesis, MIT/WHOI Joint Program, l30 pp.

Weiss, R.F., J.L. Bullister, R.H. Gammon and M.J. Warner. 1985. Atmospheric 
    chlorofluoromethanes in the deep equatorial Atlantic. Nature, 314, 
    608-610.



List of Participants


Ship's Captain 
    Richard Bowen, Woods Hole Oceanographic Institution.

Chief Scientist 
    William J. Jenkins, Woods Hole Oceanographic Institution

Co-chief Scientist 
    Donald B. Olson, University of Miami

Lamont-Doherty Geological Observatory 
    Mieczyslawa Klas 
    Kathy A. Tedesco 
    David W. Chipman

Massachusetts Institute of Technology
    Christopher L Measures

Physikalisches lnstitut des Universitt Bern 
    Jose M.D. Rodriguez

Princeton University 
    Richard J. Rotter

Scripps Institution of Oceanography/ODF 
    David L. Bos 
    Carol Conway 
    James P. Costello 
    Frank M. Delahoyde 
    Leonard T. Lopez 
    Forrest K. Mansir 
    David A. Muus 
    Ronald G. Patrick 
    Kristin M. Sanborn 
    James A. Schmitt

Scripps Institution of Oceanography 
    Mark J. Warner

Texas A&M University 
    Bret L Bergland

Woods Hole Oceanographic Institution
    Danuta Kaminski

Observers 
    Cpt. Emmanuel Bonfim de Jesus, Brazilian Naval Observer 
    Lt. Bakary Coulibaly, Cote D'Ivoire Observer




CCHDO DATA PROCESSING NOTES

Date        Contact     Date Type  Summary 
----------  ----------  ---------  ------------------------------------------
2011-04-08  Muus, Dave  BTL        Exchange, NetCDF, WOCE files online 
            Notes on Save Leg 3 rosette sample data. EXPOCODE 316N19880128 
            110406/dm
            1. Temperature, salinities, oxygen and nutrients taken from ODF 
               data, whprpasave3, dated Aug 25, 2005.
            2. CFCs and CO2 data merged from file SAVEsv.csv received from R. 
               Key Dec 10, 2010.
                PCO2 values in file but no flags. Added flag 2 for all PCO2s.
                Station 136 Cast 3 Sample 5 99.7db PCO2 180 high. ODF water 
                  samples deleted "bottle tripped about 385db".
                Deleted PCO2 and TCARBN.
                Station 136 Cast 3 Sample 27 PCO2 80 low. ODF samples okay. 
                Flag PCO2 "3".
            3. Duplicate Bottle 30, Cast 1, Station 120: CFC-12 0.001 in 
               first entry and 0.003 in second entry. Used first entry.
                  station nosamp day month year latitude longitude maxdepth 
                  maxsampdepth bottle cast depth temperature salinity
                  pressure oxygen nitrate nitrite silicate phosphate alk tco2 
                  pco2 cfc11 cfc12
                    120 37 6 2 1988 -25.675 -28.513 5433 5433 30 1 4059 1.673 
                    34.819 4124 242 25.4 0 70.3 1.73 -999 -999 -999 0.003 
                    0.001 2 2 2 2 2 2 9 9 9 2 2 120 37 6 2 1988 -25.675 -
                    28.513 5433 5433 30 1 4061 1.673 34.819 4124 242 25.4 0 
                    70.3 1.73 -999 -999 -999 0.003 0.003 2 2 2 2 2 2 9 9 9 2 2
            4. Deleted Station 108 Cast 3 Bottle 30 from SAVEsv.csv. Cast 3 
               is Gerard cast, Bottle 30 is rosette bottle.
                  Deleted Station 167 Cast 2 Bottle 25 from SAVEsv.csv. Cast 
                    3 is Gerard cast, Bottle 25 is rosette bottle.
                  Deleted Station 114 Cast 2 Bottle 29 from SAVEsv.csv. Cast 
                    2 is Gerard cast, Bottle 29 is rosette bottle. 



