TA mek Ae AH ate a sine wee ear a i a Bend Oe ¥ 3aysk ote OS Ne = see oF. yerah Die tes seen ae baw 1 wk ° DE NTE? Ra te wl : costs alten Caleta : “ ¥ che eet. i : : PTA EEN Ean . . ee aps Seek SARS eee eee Ska bk pee VR Ae EN 2! SPAR Ve . ama tebes + Bits De yee Balk ee = : wy te Pre er, tt Ot ! : 4 3 % ; Ite daetyy rere . Seale atpt mote ai wees 2 eras eee HARVARD UNIVERSITY e Library of the Museum of Comparative Zoology NOAA Technical Report NMFS SSRF-700 Expendable Bathythermograph Observations from the NUFS/MARAD Ship of Opportunity Program for 1973 STEVEN K. COOK SEATTLE, WA JUNE 1976 al@ys| NATIONAL OCEANIC AND National Marine ATMOSPHERIC ADMINISTRATION Fisheries Service NOAA TECHNICAL REPORTS National Marine Fisheries Service, Special Scientific Report —Fisheries Seri The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic i J ; resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resoure: NMFS is also charged with the development and implementation of policies for managing national fishing grounds, development and e' y off United States coastal waters, and the development and enforcement of leensetionn! Sener reements and policies. NMFS also assists the fishing industry through marketing service and economic analysis programs, and mortgage insurance and vessel construction subsidies. It collects, analyzes, and publishes statistics on various phases of the industry. ’ — “a } The Special Scientific Report—Fisheries series was established in 1949. The series carries reports on scientific investigations that document long- rm continuing programs of NMFS, or intensive scientific reports on studies of restricted scope. The reports may deal with applied fishery problems. The series also used as a medium for the publication of bibliographies of a specialized scientific nature. ‘ oe NOAA Technical Reports NMFS SSRF are available free in limited numbers to governmental agencies, both Federal and State. They are also available exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwise noted) from D83, Technical Information Division, Environmental Science Information Center, NOAA, Washington, D.C. 20235. Recent SSRF's are: ee fisheries regulations, surveillance of foreign fishing 619. Macrozooplankton and small nekton in the coastal waters off Vancouver Island (Canada) and Washington, spring and fall of 1963. By Donald S. Day, January 1971, iii + 94 p., 19 figs., 13 tables. 620. The Trade Wind Zone Oceanography Pilot Study. Part IX: The sea- level wind field and wind stress values, July 1963 to June 1965, By Gunter R. Seckel. June 1970, iii + 66 p., 5 figs. 621. Predation by sculpins on fall chinook salmon, Oncorhynchus tshawyt- scha, fry of hatchery origin. By Benjamin G. Patten. February 1971, iii + 14 p., 6 figs., 9 tables. 622. Number and lengths, by season, of fishes caught with an otter trawl near Woods Hole, Massachusetts, September 1961 to December 1962. By F. E. Lux and F. E. Nichy. February 1971, iii + 15 p., 3 figs., 19 tables. : 623. Apparent abundance, distribution, and migrations of albacore, Thunnus alalunga, on the North Pacific longline grounds. By Brian J. Rothschild and Marian Y. Y. Yong. September 1970, v + 37 p., 19 figs., 5 tables. 624. Influence of mechanical processing on the quality and yield of bay scallop meats. By N. B. Webb and F. B. Thomas, April 1971, iii + ll p.,. 2 figs., 3 tables. 625. Distributionof salmon and related oceanograpic features in the North Pacific Ocean, spring 1968. By Robert R. French, Richard G. Bakkala, Masanao Osako, and Jun Ito. March 1971, iii + 22 p., 19 figs., 3 tables. 626. Commercial fishery and biology of the freshwater shrimp, Macrobra- chium, in the Lower St. Paul River, Liberia, 1952-53. By George C. Miller. February 1971, iii + 13 p., 8 figs., 7 tables. 627. Calico scallops of the Southeastern United States, 1959-69. By Robert Cummins, Jr. June 1971, iii + 22 p., 23 figs., 3 tables. 628. Fur Seal Investigations, 1969. By NMFS, Marine Mammal Biological Laboratory. August 1971, 82 p., 20 figs., 44 tables, 23 appendix A tables, 10 appendix B tables. 629. Analysis of the operations of seven Hawaiian skipjack tuna fishing vessels, June-August 1967. By Richard N. Uchida and Ray F. Sumida. March 1971, v + 25 p., 14 figs., 21 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 630. Blue crab meat. I. Preservation by freezing. July 1971, iii + 13 p., 5 figs., 2 tables. II. Effect of chemical treatments on acceptability. By Jurgen H. Strasser, Jean S. Lennon, and Frederick J. King. July 1971, iii + 12 p., 1 fig., 9 tables. 631. Occurrence of thiaminase in some common aquatic animals of the United States and Canada. By R. A. Greig and R. H., Gnaedinger. July 1971, iii + 7 p.. 2 tables. 632. An annotated bibliography of attempts to rear the larvae of marine fishes in the laboratory. By Robert C. May. August 1971, iii + 24 p., 1 appendix I table, 1 appendix II table. For sale by the Superintendent of Documents, U.S. Goverment Printing Office, Washington, D.C. 20402. 633. Blueing of processed crab meat. II Identification of some factors involved in the blue discoloration of canned crab meat Callinectes sapidus. By Melvin E. Waters. May 1971, iii + 7 p.. 1 fig., 3 tables. 634. Age composition, weight, length, and sex of herring, Clupea pallasit, used for reduction in Alaska, 1929-66. By Gerald M. Reid. July 1971, iti + 25 p., 4 figs., 18 tables. Continued on inside back cover. -M. Gooding. May 1971, iii + 12 P. 8 figs., 2 tables. For sale OV! ) waras distribution of fish nforcement of dom: 4 635. A bibliography of the blackfin tuna, Thunnus atlanticus (Le Grant L. Beardsley and David C. Simmons. August 1971, 10 p. For sale = ag of Documents, U.S. Government Printing aw D.C, 20402. 636. Oil pollution on Wake Island from the tanker R. C. Stoner. By Superintendent of Documents, U.S. ernment Printing Office, Washi D.C. 20402. 637. Occurrence of larval, juvenile, and mature crabs in the vicinit Beaufort Inlet, North Carolina. By Donnie L. Dudley and Mayo H. Ju August 1971, iii + 10 p., 1 fig., 5 tables. For sale by the Superintend Documents, U.S. Government Printing Office, Washington, D.C. 20402. 638. Length-weight relations of haddock from commercial landings in England, 1931-55. By Bradford E. Brown and Richard C. Hennemuth. 1971, v + 13 p., 16 figs., 6 tables, 10 appendix A tables. For sale Superintendent of Documents, U.S. Government Printing Office, Wash D.C. 20402. 7 639. A hydrographic survey of the Galveston Bay system, Texas 1963-66. | E. J. Pullen, W. 3 Trent, and G. B. Adams. Getober 1971, v + 3p. figs, 12 tables. For sale by the Superintendent of Documents, Government Printing Office, Washington, D.C. 20402. He 640. Annotated bibliography on the fishing industry and biology of the crab, Callinectes sapidus. By Marlin E. Tagatz and Ann Bowman Hall. 4 1971, 94 p. For sale by the Superintendent of Documents, U.S. Gove Printing Office, Washington, D.C. 20402. ' 641, Use of threadfin shad, Dorosoma petenense, as live bait during ex mental pole-and-line fishing for skipjack tuna, Katswwonus pelamis, in Haw: By Robert T. B. Iversen. August 1971, iii + 10 p., 3 figs., 7 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washing- ton, D.C. 20402. f 642. Atlantic menhaden Brevoortia tyrannus resource and fishery —analysis of decline. By Kenneth A. Henry. August 1971, v + 32 p., 40 figs., 5 appendix figs., 3 tables, 2 appendix tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 7 . \ 643. Surface winds of the southeastern propical Atlantic Ocean. By John M. Steigner and Merton C. Ingham. October 1971, iii + 20 p., 17 figs. For sale by the Payer ag of Documents, U.S. Government Printing Office, Ws ton, D.C. 20402. = 644. Inhibition of flesh browning and skin color fading in frozen fillets of yelloweye snapper (Lutzanus vivanus). By Harold C. Thompson, Jr., and Mary H. Thompson. February 1972, iii + 6 p., 3 tables. For sale by the Superinten- dent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 645. Traveling screen for removal of debris from rivers. By Daniel W. Bate: Ernest W. Murphey, and Martin G. Beam. October 1971, iii + 6 p., 6 figs table. For sale by the Superintendent of Documents, U.S. Government Print Office, Washington D.C. 20402. 646. Dissolved nitrogen concentrations in the Columbia and Snake Rivers” 1970 and their effect on chinook salmon and steelhead trout. By Wesley J. F August 1971, iii + 7 p., 2 figs., 6 me For sale by the Superintendent of Documents, U.S. Government Printing , Washington D.C. 20402. ja 647. Revised annotated list of parasites from sea mammals caught off the west coast of North America. By L. Margolis and M. D. . March 1972, ii + 23 p. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. ae if _ LIBRARY AUG 1 2 1976 Se ee ee HARVARD UNIVERSITY NOAA Technical Report NMFS SSRF-700 Expendable Bathythermograph Observations from the NUFS/MARAD Ship of Opportunity Program for 1973 STEVEN K. COOK SEATTLE. WA JUNE 1976 UNITED STATES NATIONAL OCEANIC AND / National Marine DEPARTMENT OF COMMERCE wa ATMOSPHERIC ADMINISTRATION vA Fisheries Service < Elliot L. Richardson, Secretary Robert M. White, Administrator Robert W. Schoning, Director = For Sale by the Superint t he Su endent of Documents, U.S. Government Printing Off Washington, D.C. 20402 Stock No. 003-017-00382-5 ee S The National Marine Fisheries Service (NMFS) does not approve, rec- ommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication furnished by NMFS, in any advertising or sales pro- motion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. CONTENTS Page LOPUTRET RIED 5 2.5.6 dues hints ond CUERPO ole Bex do I ae a 1 ANREES OH STORY 5.0 410.5 1015.0 0015 0G OORT ARC Anes Al eg on 1 DAU oRACE UIST IONE ANOMDLOCESSIN Deere tthe tape eer a. aS uae ee Se OS eT rea Ee ee re aos 1 DISCUSSION MMPI nares re ee ences ee ee Law ee ae Bly tie le hava aye Goa witb ees Ms: ean: 1 {UREMEQGE MMGAISNS ~ o < 5s Sadia ateicug Oe OPO Eee SOG ie inoue. 5 6 acne en 2 CULT DO? WIEETOD « 0.6 0:9:0 0 Glo SOE SAkcre eRe nett ae ES eR RR Tr or ot ne re r= ae 2 IL@ayt) CEARDAG 6 & ahidhe eat/8: Shes ean yeah Monae ees asec erick er Neh a een eo gL 2 EG CES eee ee 7 I Pe coed cody 3, wus ead meio Board Se oe es 2 CGanippealCULce nl Mn te: Ge re ee hes eA eye clr lias cots s cad oe eat Roh odie GE ER ele 2 WieESlernmNOLUNeALantlew ey ween. pe. eae nee. te, Se, Cuts eA Slices | ait alty) Sic ee ae sea 2 CUPS CLEAUI EP Ce eee ae ee en eee eae ae. Were tesa: Sys bec eke Sem. vote oo cas 2 ColdicellPpremrrrr er rrr cc oe ne en es SARE ee Oe. eit oe. 5: 3 SHUM VALEISIODCAWALCISUCON Geer rr cin eect acme meee MCE 3 ANGE OATES) « 01 5 & G55 BRB aye aR SS eee a ee ere oe eye 3 MCE RAULERCICILEC MPEP PINS tery etree ers ry cH ek cians Sv oni cuomersachel ee Ohind ceuicnaieh de, epedunise) cutie cer qekaueueteusen sheseaeee 3 LETTERS ails ©. 0.0 0 0 Gc 36.8 24 OSS ROIS SE aR ee Cae ge eee Te 3 Figures ipeDeltarArgentina: diallstations14-22, 1-2, January 1973.26 occ. cscs we sp oes Sie e icine wpe obernemre Saelenet 4 Pee GUS nipermiaU2) stations 1-225, 12-15 Pebruary 1978) sic ors < sistas sheane: «end .mnue ches otis ene end ayer stos sane = 5 SEG SLippen mi oU4 wstaLions 1-10. 20-24- April Old) «<< cies cveschs ce ene cic. ereie tho. eta Meuse sreuiln = eeosiorie ae ks 6 Ae GU eT Ader OU ASUALIONS 29s Lav AUPUSE LOTS: « .. 6 scxspeyecs cite © mifejene epee sere ies geeinn > eo njausieyera’s. 5 erspeseieicncesue creel + Spthene =ySebN Soke Snel 10 See MOnmACrArGOnlGUDaSLALIONS 26214. Li-1S; JUNC 19TS: a esse cess Ae cae sees mee moe lee eee he se ee 11 Om Monnichigearolierstations” 1951 November 1973) <2... dee eaee weiss qapeye ae eegs gan es te Wns aed 12 Ome MormacrAr. gonial astations lal, 5 November 1973) .2j.o8 ice Gor = 0c5 reser eyerege © 0S tus eee euene © op eaensoush= © obke 13 iil yaar" Ls mete ts ERS wi wig ster pas a se 3 1 er raids RP err aie Te a 0D (rT SCS ae Sie, CNEL Pugh a POt «arly She yodppeye Ls, Prey ve @ Shi OE ho GVGL eral, AE PL 95-AE te n7er ~wliwa nil Ale TUi seeps G LTot amenity 18 oy 7 ; ea , 7 —“e. ae ‘ » ms 7 a 4 Expendable Bathythermograph Observations from the NMFS/MARAD Ship of Opportunity Program for 1973 STEVEN K. COOK?! ABSTRACT Results of the third year of operation of the NMFS/MARAD Ship of Opportunity Program are presented in the form of vertical distributions of sea surface temperature and salinity. Included are descriptive analyses of the most dynamic transects showing the Caribbean/Yucatan/Loop/Florida Current regimes, the Gulf Stream, associated eddies, and the bottom cell of cold water off the U.S. east coast. Operational and data management procedures also are discussed. INTRODUCTION In midyear of 1970 a cooperative expendable bathyther- mograph (XBT) program was initiated between the National Marine Fisheries Service (NMFS) and the Maritime Administration (MARAD) of the U.S. Department of Commerce. The program, conducted in support of the Marine Resources Monitoring Assessment and Prediction Program of NMFS, involved the use of Maritime Cadets from Kings Point Maritime Academy to collect XBT data on board merchant ships operating along the east and Gulf coasts of the United States. The objective of this cooperative program was to identify and describe seasonal and year-to-year variations of temperature and circulation in the major current regimes of the eastern tropical Atlantic, Caribbean Sea, Gulf of Mexico, and western North Atlantic, utilizing merchant ships as relatively inexpensive platforms for the collection of data. The program objective has been modified recently to eliminate the tropical Atlantic and most of the Caribbean, concentrating on the western North Atlantic and Gulf of Mexico. AREAS OF STUDY Ship routes were selected to obtain regular sampling in the most dynamic areas of the Gulf of Mexico and western North Atlantic. The features of principal interest were the Yucatan Current, Gulf Loop Current, Florida Current, Gulf Stream, Shelf Water-Slope Water front, and a cold water cell in the Middle Atlantic Bight. DATA ACQUISITION AND PROCESSING Subsurface temperature data were obtained by use of Sippican XBT systems. At the same time surface water samples were collected with bucket thermometer units for later analysis to determine salinity. The surface water samples were analyzed on shore using a Beckman inductive salinometer calibrated with standard (Copenhagen) water at ° least once every 30 samples. The XBT traces were ‘Atlantic Environmental Group, National Marine Fisheries Service, NOAA, R.R. 7A, Box 522-A, Narragansett, RI 02882. submitted to the National Oceanographic Data Center (NODC) where they were digitized, key punched, and quality controlled. Finally, these processed data were listed in printout form and machine plotted. The plots produced by NODC were essentially camera ready and needed little hand correcting. The few corrections necessary were made by discarding anomalous XBT observations that could not be supported by other associated data such as sea surface temperature or other nearby XBT observations. Conse- quently a vertical section plot may have one or two missing observations resulting from the deletion of inaccurate subsurface data. All data collected were archived by the NODC and are available to interested persons through the NODC, Washington, D.C. 20235. Approximately 146 additional XBT observations and associated surface data were archived at the NODC, but not discussed in this report. The observations were too scattered in time and space to be formed into meaningful transects. Further details concerning the acquisition or processing of data from the cruises considered here can be obtained from the author. DISCUSSION This third year of operation of the NUFS/MARAD Ship of Opportunity Program (SOOP) was highlighted by a major program change. Instead of transoceanic XBT transects consisting of 4-6 observations per day, a more intense coverage over a smaller geographical area (hourly observa- tions for the first 24 h after leaving port and the last 24 h before reentering port) was initiated. This has made possible the monitoring of portions of the Shelf Water-Slope Water front, North Wall of the Gulf Stream, Gulf Loop Current, and associated eddies. The SOOP effort for 1973 consisted of a total of 15 cruises, 7 sailing from New Orleans and 8 from New York. Twenty-three transects of subsurface temperature data and associated surface data were obtained. A total of 357 XBT’s were launched; of these, 211 (60%) were considered of sufficient quality to be incorporated into the transects presented in this report. Participation of midshipmen as data collectors does not allow for year-round coverage, because of the transition period in January-February, when one group of cadets goes back to school and a new group begins sea duty. TRANSECT ANALYSIS Gulf of Mexico Over the years there have been several descriptions of the Yucatan/Loop/Florida Current regimes, but many ambiguities still exist. For purposes of this report, I have used the criteria of Nowlin and McLellan (1967) for describing the Loop Current as that water within the Gulf of Mexico that has just passed through the Yucatan Channel and has not yet exited through the Straits of Florida (usually about midway between Cuba and the western Florida Keys). The current flow into the Gulf of Mexico between the western tip of Cuba and the Yucatan Peninsula was referred to as the Yucatan Current and the current flow upstream from there (into the Caribbean Sea) was referred to as the Caribbean Current. Loop Current.—The Loop Current showed up on transects conducted in January, February, April, August, October, and November (Figs. 1-6). The downward slope (southward) of the isotherms, such as between stations 16 and 17 in Figure 1 for January, indicated the approximate position of the Loop Current as it passed from the Yucatan Channel into the Gulf of Mexico. About a month later the Loop Current was transected again near the Yucatan Channel as shown by the slope of the isotherms between stations 7 and 8 in Figure 2. In April (Fig. 3), the Loop Current was found between stations 5 and 6. A comparison of Figures 1, 2, and 3 shows the Loop Current extending further into the Gulf of Mexico, from its January position at approximately lat. 23°N to approximately lat. 24°N in February and to lat. 25°N in April. This northward migration was consistent with previous observations of the behavior of this current (Boisvert 1967). The complex temperature structure of the section made in August (Fig. 4) requires a close examination of the data to discern the difference between Yucatan Current, Loop Current, and an associated eddy. At this time, I feel the Yucatan/Loop Current system was transected four times. Following the temperature structure from south to north, the downward tilting of the isotherms between stations 29 and 28 indicated the normal westward flow of the Caribbean Current just prior to entering the Yucatan Channel. The upward tilting of the isotherms between stations 26 and 23 indicated an eastward flow (into the page in the vertical section), and the downward tilt of the isotherms between stations 20 and 19 indicated a westward flow. Finally, the structure between stations 16 and 12 indicated eastward flow, apparently the northernmost crossing of the Loop Current. The configuration of the isotherms between stations 10 and 1 suggest the presence of a warm core eddy and are discussed in the following section. Another possibility was that the flow pattern through the Yucatan Channel had diverged and become multiaxial as suggested by Cochrane? in 1963, with more eastward “Cochrane, J. D. 1963. Yucatan Current. Texas A&M College, Department of Oceanography and Meteorology, Ref. 63-18A. Unpubl. rep., 25 p. Atlantic Environmental Group, National Marine Fisheries Service, NOAA, Narragansett, RI 02882. divergence flowing around Cuba and into the Straits of Florida; and the western axis looping through the Gulf between stations 16 and 12 at about lat. 25°N. In later crossings the Loop Current appeared to recede from the Gulf. In October it was crossed at about lat. 24°N (Fig. 5, stations 16-21) and in November at about lat. 22°N (Fig. 6, stations 14-16). Eddies.—Eddy structures were detected in the north- eastern Gulf of Mexico on transects conducted in January, February, August, and October (Figs. 1, 2, 4, 5). In January (Fig. 1) the temperature structure between stations 17 and 21 showed some evidence of a weak anticyclonic eddy with a diameter of approximately 125 nautical miles. In February (Fig. 2), the doming effect of the isotherms between stations 1 and 7 suggested the existence of a warm core anticyclonic eddy, possibly a recrossing of the same eddy seen the previous month. Unfortunately, the lack of XBT observations to the north of station 1 prevent the | positive identification of this structure as a remnant anticyclonic eddy. In August (Fig. 4), the temperature structure found between stations 10 and 1 was an indication of a warm core, anticyclonic eddy that has possibly broken off from the main flow of the Loop Current. This was consistent with past observations of Loop Current activity (Leipper 1970). The width of the eddy at this crossing was about 125 nautical miles and extended to depths of greater than 700 m. In October (Fig. 5), another warm core, anticyclonic eddy was transected. The transect crossed through the eddy between stations 5 and 11 (approximately 125 nautical miles) and the eddy extended to a depth of greater than 750 m. Caribbean Current.—The Caribbean Current, described by Boisvert (1967) as one of the most persistent and well defined of the major currents, is broad and relatively slow moving. It was seen in the SOOP transects south of the Yucatan Channel as a northward declination of isotherms. Utilizing this characteristic, we found the Caribbean Current in February, April, August, and November (Figs. 2730456): In February (Fig. 2), the Caribbean Current was crossed between stations 13 and 22. Temperature structure between stations 19 and 21 indicated an area of possible counterflow. In April (Fig. 3), the Caribbean Current was again indicated by the general upward incline of the isotherms between stations 9 and 15. In August (Fig. 4), the upward incline of the isotherms between stations 28 and 29 indicated the westward flow of the Caribbean Current just prior to entering the Yucatan Channel. In November (Fig. 6), an indication of the Caribbean Current appears between stations 16 and 20. Western North Atlantic Features described in the western North Atlantic include the North Wall of the Gulf Stream, Shelf Water-Slope Water front, bottom cold cell, and eddies formed by the Gulf Stream. Temperature sections obtained on four New York to Bermuda sections made during May, June, and November (Figs. 7-10) show some of these features. Gulf Stream. — Using the criterion of 15°C at 200-mdepth (Worthington 1964) to indicate the North Wall of the Gulf Stream, we found four crossings of the North Wall in May, _ June, and November (Figs. 7-10). In mid-May (Fig. 7), the North Wall was indicated just to the east of station 13 (approximately lat. 37°00'N, long. 69°00'W). Unfortunately, there are not enough observations to completely describe the crossing. In June (Fig. 8), just the opposite occurred. Observa- tions were made from the east right up to the North Wall, discontinued for about 130 nautical miles, then recommenc- ed. A crossing of the North Wall is detectable, but not well defined, between stations 19 and 18 (approximately lat. 87°15'N, long. 69°30'W). The November section (Fig. 9) shows the North Wall of the Gulf Stream between stations 15 and 16 (lat. 37°30'N, long.71°00'W). In the transect made 4 days later (Fig. 10) the North Wall of the Gulf Stream showed up at station 10 (lat. 38°00'N, long.71°00'W). Cold Cell.—The cold cell, sometimes referred to as winter water (water less than 8°C), has been described by Ketchum and Corwin (1964) and Whitcomb (1970). This feature was transected on four occasions (Figs. 7, 8, 9, 10). These four crossings show how the cold cell degenerates throughout the summer. The first crossing in May (Fig. 7) shows a cold cell with a temperature range of 6°-8°C until finally in the last of November (Fig. 10) the cell structure is barely detectable and has warmed to 14°C. In May (Fig. 7), a cell of bottom water extended 80 nautical miles offshore to a maximum depth of 75 m, with a temperature range of 6°-8°C. In June (Fig. 8), the cold cell of bottom water was still evident, although by this time the cell had begun to warm and extend out to the shelf break. The November section (Fig. 9) shows still a further warming and decay of the cold cell. The extent of the cold cell had decreased to less than 60 nautical miles and warmed to a range of 12°-14°C. The second November section (Fig. 10) showed the cold cell had eroded to less than 30 nautical miles extent and warmed to 14°C. Shelf Water-Slope Water Front.—The Shelf Water- Slope Water front was transected in May just to the east of station 5 (Fig. 7), indicated by a thermal change from 10° to 17°C in about 18 nautical miles. Low sea surface salinities and temperatures out to station 5 also indicated the extent of the shelf water. In June (Fig. 8), the front appeared between stations 25 and 24. At this time there was less sea surface temperature change to indicate the front, instead the most pronounced surface signature of the front was in the form of the strong surface salinity gradient changing slope and sign at station 23. The November section (Fig. 9), shows that the Shelf Water-Slope Water front had no expression in either surface temperature or salinity, but a weak temperature gradient between stations 7 and 8, at about 50-m depth, suggests that the front might have been present there. In the transect made 4 days later (Fig. 10), a definite surface signature of the shelf water was apparent in both sea surface salinity and temperature. The Shelf Water-Slope Water front did not show up in the subsurface data on this transect, but surface salinities of less than 34%o readily identify the shelf water region. ACKNOWLEDGMENTS Appreciation is extended to the Maritime Academy Training representatives in New York and New Orleans, M. Chicurel and D. Thompson, respectively. Their diligent efforts to place midshipmen on board ships that were scheduled to traverse preselected oceanic areas were instrumental to the success of this program. In addition, thanks are extended to the Moore McCormack Lines and Grace Prudential Lines of New York and the Delta Steamship Company and Lykes Brothers of New Orleans. LITERATURE CITED BOISVERT, W. E. 1967. Major currents in the North and South Atlantic Oceans between 64°N and 60°S. U.S. Nav. Oceanogr. Off., Tech. Rep. TR-193, 92 p. KETCHUM, B. H., and N. CORWIN. 1964. The persistence of “winter” water on the continental shelf south of Long Island, New York. Limnol. Oceanogr. 9:467-475. LEIPPER, D. F. 1970. A sequence of current patterns in the Gulf of Mexico. J. Geophys. Res. 75:637-657. NOWLIN, W. D., JR., and H. J. McLELLAN. 1967. A characterization of the Gulf of Mexico waters in winter. J. Mar. Res. 25:29-59. WHITCOMB, V. L. 1970. Oceanography of the Mid-Atlantic Bight in support of ICNAF. September-December 1967. U.S. Coast Guard Oceano- graphic Report No. 35, CG 373-35, 157 p. WORTHINGTON, L. V. 1964. Anomalous conditions in the Slope Water area in 1959. J. Fish. Res. Board Can. 21:327-333. FIGURES The figures are grouped by geographical location and time. They consist of two vertical sections of temperature, a plot of surface temperature and salinity versus distance along the transect, and a locator chart. GULF OF MEXICO TRANSECTS Figures Vessels Date i Delta Argentina 1- 2 Jan. 1973 2 Gulf Shipper 12-15 Feb. 1973 3 Gulf Shipper 20-24 Apr. 1973 4 Gulf Trader 1- 2 Aug. 1973 5 Gulf Trader 14-15 Oct. 1973 6 Delta Norte 3- 5 Nov. 19738 WESTERN ATLANTIC TRANSECTS 7 Mormac Argo 12-13 May 1973 8 Mormac Argo 17-18 Jun. 1973 9 Mormac Rigel 1 Nov. 1973 10 Mormac Argo 5 Nov. 1973 {C) *® TEMPERATURE DEGREES (METERS) ¢@ DEPTH (METERS) 4 DEPTH GULF OF MEXICO TRANSECTS PARAMETER AT SURFACE 27 26 (0/700) 2s 24u 23 GSALINITY 22 21 0. 60. 120. 180. 240. 300. 360. 420. 480. S4O. DISTANCE (N. MILES) 22 21 20 18 17 16 15 14 22.0. so _] 27 50 100 100 180 —} 150 18.0. - OS UL 14 sohbet = dcbatind b> + 0 a7 ie ae S.0 aan 100 2).0. 2.0 19.0. 8 re He a cee 200 s.o 1§.0) 4.0 1§.0. 3.0 0. 2.0 300 12.0, 1.0 i}.0 a | 4oo 19.0, oJ ' fe |_ soo 0 slo aa 6 |_ 600 1.0 0 a ne 700 i A = = 0 800 0. 150. 300. 450. 600. 750. 900. 1050. 1200. 1350. (0/00) GSALINITY 30 60 70 30 30 20 20 30 60 70 CRUISE TRACK PLOT Horizontal distribution of sea surface temperature (°C) and sea surface salin- ity (%0), and vertical distribution of temperature (°C) in the upper 200 and 800 m. Figure 2.— Gulf Shipper, 7302, stations 1-22, 12-15 February 1973. {C DEGREES mM TEMPERATURE (METERS) ¢ DEPTH (METERS) 4 DEPTH PARAMETER AT SURFACE ne were ——* ; 3: 27 as ~ - 7 c Or files! ro —= =} ih 3°: © pe q 33: 8 : 32. oo 4 31. = Yu ees 24 4 on = 3. 5 li 26. >> ron BIE fo) eat gee 3i: ee + Ean T 92 vy he. apt ee eee 0. 160. 320. 480. 640. 800. 960. 1120. 1280. 1440. DISTANCE (N. MILES) oS 30 80 70 0 sop sb 0 50 bo 8) 100 100 150 150 200 200 0. 160. 320. 480. 640. 800. 960. 1120. 1280. 1440. CRUISE TRACK PLOT 0 100 200 300 Horizontal distribution of sea surface uoo temperature (°C) and sea surface salin- ity (%o), and vertical distribution of temperature (°C) in the upper 200 S500 and 800 m. 600 700 800 Q. 160. 320. 480d. 640. 800. 960. W200. Wesdh war Figure 3.—Gulf Shipper, 7304, stations 1-15, 20-24 April 1973. (C) * TEMPERATURE DEGREES (METERS) 4 DEPTH (METERS) 4 DEPTH 30 2g 28 27 10) 100 150 200 200 300 4OO S00 600 700 800 PARAMETER AT SURFACE Sie =) oO a 2 > = z = lou wm © 36. Os go. 180. 270. 360. 4SO. Suo. 630. 720. DISTANCE (N. MILES 30 60 0 30 30 SO Lie 20 20 | 150 |_ 200 = ae 720. CRUISE TRACK PLOT O-—-WUNMI MN OFromMo —-UMSTNWORr- @WO [op] OOD SOE OTD a wt wt se Mw ccc CCC WJ fav) Horizontal distribution of sea surface temperature (°C) and sea surface salin- ity (%o), and vertical distribution temperature (°C) in the upper 200 and 800 m. Q. 90. 180. 270. 360. 4so. S40. 630. 720. Figure 4.— Gulf Trader, 7308, stations 1-29, 1-2 August 1973. DEGREES *M TEMPERRTURE (METERS) 4 DEPTH (METERS) 4 DEPTH PARAMETER AT SURFACE Sir. 36. a5. 34. | T 180. 240. 300. 360. 420. 4860. DISTANCE (N. MILES) m s> Mo OTF On0O—- = -— Re RR RR WN 120. 16) 100 150 180. 240. 300. 360. 420. 480. |_ 200 | 300 | 400 | S00 | 600 700 800 I | T 180. 240. 300. 360. 420. 480. (0/00) GSALINITY 30 60 30 Ke —~ 30 1 8) i, Ne 20 20 90 80 CRUISE TRACK PLOT Horizontal distribution of sea surface temperature (°C) and sea surface salin- ity (%o), and vertical distribution of temperature (°C) in the upper 200 and 800 m. Figure 5. — Gulf Trader, 7310, stations 1-21, 14-15 October 1973. PARAMETER AT SURFACE o 30 a7. = 2g 36. 5 ig) 28 35. S al a 27) Su boos = e Pee c . Fa 2 25 Sie = 24 a Jie = 23 29. = 22 28. * 0. 120. 240. 360. 480. 600. 720. 840. 960. 1080. DISTANCE (N. MILES) 100 30 60 0 0 30 = 150 so wn c (ee) — b ee — 160 - ion 3= e a =] ~ 150 150 SY 200 200 10 100 390 80 Q. 120. 240. 360. 4so. 600. 720. 840. 960. 1080. CRUISE TRACK PLOT OoO-W TOW wo ~-ono “ AM wzlro Daas A el - CM ——————— 100 Fis an > 6.0 = ———_ tgiee 5.0 © ea Z ad . 2 w £8 lu pS WEE Tee = 0.0 wu 8.0 = 5 NE SE 5 £ 8.0 x 300 a ae a 12—,2.0 Horizontal distribution of sea surface 9 yoo = temperature (°C) and sea surface salin- * ity (%0), and vertical distribution of temperature (°C) in the upper 200 Soo }o.0 and 800 m. 600 ms 700 800 800 0. 120. 240. 360. 480. 600. 720. 840. 960. 1080. Figure 6.—Delta Norte, 7311, stations 1-20, 3-5 November 1973. S (C) DEGREE M TEMPERATURE (METERS) ¢ DEPTH (METERS) ¢ DEPTH WESTERN ATLANTIC TRANSECTS PARAMETER AT SURFACE aie apes ay: 4 ae a ey = 50 TI 35. 19 18 = 34. 1 is = 33. 1 iN 4 a2 1 | 31. ies 10 30. T T [e QO. 4Oo. 80. 120. 160. 200. 240. 280. 320. DISTANCE (N. MILES) 0 0 50 so 100 100 150 150 200 200 0. 40. 80. 120. 160. 200. 240. 260. 320. 0 0 100 100 200 200 300 300 yoo _ 400 500 — 500 600 _| 600 0 7Ah) zoe Boc __| 800 80. 120. 160. 200. 240. 280. 320. (0/00) GSALINITY 60 70 60 CRUISE TRACK PLOT Horizontal distribution of sea surface temperature (°C) and sea surface salin- ity (%o), and _ vertical distribution of temperature (°C) in the upper 200 and 800 m. Figure 7.—Mormac Argo, 7305, stations 1-13, 12-13 May 1973. 10 (C) *X TEMPERATURE DEGREES (METERS) ¢+ DEPTH (METERS) 4 DEPTH 2s 2u 23 22 21 20 19 18 17 16 15 14 SO 100 150 200 PARAMETER AT SURFACE eli/e silsic bess. 134, =33). E32. Shilo 130. e29F (0/00) GSALINITY I T 60. 120. 180. 240d. 300. DISTANCE (N. MILES = oO oD un - 60. 120. 180. eyo. 300. 60. 120. 180. 2u0. 300. 28. | 360. 420. 480. 80 70 60 so so vo | SO 4O 4O 200 30 30 80 70 60 360. 420. 480. CRUSE TRACKS SG Horizontal distribution of sea surface temperature (°C), and sea surface salin- ity (%0), and vertical distribution of temperature (°C) in the upper 200 and 800 m. 360. 420. 480. Figure 8.—Mormac Argo, 7305, stations 28-14, 17-18 June 1973. 11 {C) *M TEMPERATURE DEGREES (METERS) 4 DEPTH (METERS) 4 DEPTH PARAMETER AT SURFACE 2s —- 24u 23 22 21 20 19 18 17 120. 160. 200. 240. DISTANCE (IN. MILES) = Le LO = oOo o “we we _— 50 100 150 200 300 4o0o 500 600 700 800 160. 200. 240. 0. uO. 80. 120. 280. 280. ST 34. 320. 50 200 320. 200 300 4OO0 S00 600 700 800 320. (0/00) GSALINITY 60 70 60 CRUISE TRACK PLOT Horizontal distribution of sea surface temperature (°C) and sea surface salin- ity (%o), and vertical distribution of temperature (°C) in the upper 200 and 800 m. Figure 9.—Mormac Rigel, 7311, stations 1-19, 1 November 1973. 12 26 2s 2yu 23 22 21 20 19 18 17 16 1S 14 13 (C) * TEMPERATURE DEGREES (METERS) ¢ DEPTH 200 (METERS) 300 4OO ¢ DEPTH 500 600 700 800 PARAMETER AT SURFACE 37 36. & Sea oO 35. = lk s Bye a = +33. 2 wn Eee og =e. Sil. i ] ea ls eae als = 60. 120. 180. 240. 300. 360. 420. 4so. suo. DISTANCE (N. MILES) es 2 oy 80 70 50 . — = 0} so |_so 22 | 100 2.0 4a 0.0 | 150 0.0 bed 200 30 = nT ie S 3 2 300. 360. 420. 480. S40. CRUISE TRACK PLOT w (fay Jem + 0 20 |_ 100 2) Sars aig 200 9.0 ay | 300 Horizontal distribution of sea surface | yoo temperature (°C) and sea surface salin- ity (%c), and vertical distribution ios of temperature (°C) in the upper 200 |. S00 and 800 m. 16 —18.0 | 600 ES TA0KGI 800 | I “aA I | 60. 120. 180. 240. 300. 360. 420. 480. S4Q. Figure 10.—Mormac Argo, 7311, stations 1-17, 5 November 1973. 13 t% U.S. GOVERNMENT PRINTING OFFICE: 1976—697-340/93 REGION 10 so 40 30 vy ‘ be H.owy Acme Bookbinding Co., Inc. 100 Cambridge St. | | Charlestown, MA 02129. erences Mahet PAG NaS eels z= Averitt Panto atey need 9 we Ae en tae pee vt ’ on hut VR yee wee