MID-PACIFIC OCEANOGRAPHY Parts II and III Transequatorial Waters, 1950-51 SPECIAL SCIENTIFIC REPORT-FISHERIES No. 131 UNITED STATES DEPARTMENT OF THE INTERIOR FISH AHD WILDLIFE SERVICE Explanatory Note The series embodies results of investigations, usually of restricted scope, intended to aid or direct management or utilization practices and as i^uides for administrative or legislative action. It is issued in limited quantities for the official use of Federal, State or cooperating Agencies and in processed form for economy and to avoid delay in publication. 5/801 United States Department of the Interior, Douglas McKay, Secretary Fish and Wildlife Service, John L. Farley, Director MID- PACIFIC OCEANOGRAPHY II By Townsend Cromwell and MID-PACIFIC OCEANOGRAPHY III By Thomas S„ Austin Special Scientific Report: Fisheries No„ 131 WASHINGTON: JUNE 1954 MID-PACIFIC OCEANOGRAPHY II TRANSEQUATORIAL WATERS JUNE - AUGUST 1950 JANUARY - MARCH 1951 By townsend cromwell!/ pacific oceanic fishery investigations honolulu, t. h„ 1/ Presently employed at Scripps Institution of Oceanography La Jolla, California CONTENTS Page 1I1L l O Cj. LlL I i. \J 1 1 oooaeaoaoooooooooooooooaooooooooooooooQooaoo -' Vessels, equipment, and procedures Oooooo.oo0....oooooo.o. 3 Vessel and vessel equipment Ooocio0ooooo....oooooc,ooo 3 L'QllcCllun OX Udl a ooooooaoooooaoooaoooooooooaooooooo ~* r^rULcbolUg OX Qala ooooooooeoeooaoooaooooooooooooooo " j\.Xlcll y 5 G S OX ClcAL cl oeoo 00 oe 0000 0000 OOOOOdoooGOOOOOOOOO " Some results of Hugh M„ Smith cruises 5 and 80„0oo...oo.oo 5 L-' y XI 7 6 oooooaoaoaooDoooaoooooaooaooooooooooooooooo O /iC iVliO Wlc ^-K e XIXe IX Lo oooeooaooosoooaoooooooooooooaooooooooo *-* XjI lei at U 1 c ClLc U coao«oo 0*0000000000000000000000000000000 7 Remarks about the oceanographic data Ooooo.. .000000000000 10 a\. U. X 111 ar Y Sl at lOn Q at a oooooooooooooooooooooooooooooo 1 V/ 1 cLDUlaLcQ Udla 00000000000 oooaaoooc 000 0000000000000 1. \J Vw*iulSc J ooooeooeooooooooooooooooooooooooooooooo 000 * " V I Ulo" O 00OOOOOO OOOOOOOOOOOOO oqo a 00 00 00 OO (it) I) uOOOOO -1- X J-jlST. OJ Il£Ur6S CgO o < OCC C CCQOOOOOOQOOOOOOOOOOOOOOOOOOOOOOOO Aw Tabulated data MID-PACIFIC OCEANOGRAPHY - II Introduction This is the second in a series of reports planned to pre- sent oceanographic data obtained by the Pacific Oceanic Fishery In- vestigations of the U. S„ Fish and Wildlife Service „ The first (Cromwell 1951) presented oceanographic data in tabular and graphical form with discussions of some of the results of cruise 2 of the Hugh M. Smith, the first equatorial cruise of the POFI program concerned primarily with the collection of physical and chemical dataQ This pre- sent report is concerned with Smith cruises 5 and 8, the second and third equatorial cruises with similar objectives „ The primary purpose of this report is to present the tabulated data and cross-section drawings J"' There is only a brief description of results and no attempt is made to relate the present work in a comprehensive fashion to that done by others in the equa- torial Pacific. The primary objective of these oceanographic studies in the equatorial Pacific is to provide information that may be related to biological productivity and particularly to the occurrence of the tunas, POFI's oceanographic program, up to the present time, has centered on describing the distributions of physical and chemical properties and on determining the regions where vertical motion of a type important to productivity occurs 0 Vessel, Equipment, and Procedures Vessel and vessel equipment; The Hugh M. Smith is a former U. S„ Navy YP of 700 dead weight tons, converted to carry out oceanographic and fishing researchQ A previous report (Cromwell 1951) provides a photograph of the vessel and describes the oceano- graphic and other scientific equipment aboardQ Collection of data; The methods used at sea to collect physical and chemical data were essentially as described in the re- port mentioned above„ Serial temperature observations were made using protected reversing thermometers. Water samples were ob- tained using Nansen-type bottles (see frontispiece). The concentra- tions of dissolved oxygen were determined by the Winkler titration 2/ All cross -sections and tabulated data are grouped at the end of the text0 method and of the dissolved inorganic phosphate bv the Automatic Servo-operated Photometer (Snodgrass et al„ 1953L Portions of each water sample were stored in citrate bottles and returned to the Honolulu laboratory for chlonnity analysis by the Knudsen method„ Processing of data: Sampling depths were determined using reversing thermometers 0 The readings of protected and un- protected thermometers were adjusted to in situ values by means of graphs o Thermometric depths were computed and plotted on a graph of wire length minus thermometric depth against wire length as developed by R. 00 Reid and described by La Fond (1951 L The actual depths at which all water samples were obtained were deter- mined from this curveG Analyses of data; The analyses of the data (their prepa- ration from the tables listing observed values to final presentation in the form of cross sections) were carried out differently from those reported by Cromwell (1951) for cruise 2„ Data from that report have been re-analyzed and the resulting set of cross sections appear, in part, in a report by Cromwell (1953) and the remainder in a paper by Montgomery (1954)„ For this report, the treatment of data was similar to that employed by Montgomery for one series of Smith stations along the 158 W, meridian (Montgomery 1954)Q The procedure followed here will be described briefly for those who do not have access to his paper and to point out differences from his method,, A temperature -vs0 -depth curve was drawn for each sta- tion, the curve passing through each observed point (figQ 1)0 The BT trace was used to define detail in drawing the upper 200 meters of the curve. A temperature -salinity fT-S) curve then was drawn on the same graph using the same temperature scale,, Thus, the depth or depths of occurrence of any particular salinity can be determined by referring to the temperature -depth curve0 Successive T-S curves were placed on a light table and altered, where necessary, so that the station-to-station changes were as regular as the data would allow,, Since curves along which sigma-t is constant appear printed on the graph, the depth of any particular value of sigma-t can be read by referring to the temperature-depth curve0 In constructing the cross sections, the depths of selected values for salinity and sigma-t were determined as above and plotted against distance,, The isopleths were penciled lightly on the cross section,, In addition, the values of actual observations were written onto a second cross section using an equivalent pair of scales. The two were superimposed on a light table and the isopleths modified consistent with the observed values,, Up to this point in the treatment of the data, the procedures follow closely those described by Montgomery (1954)0 Montgomery used an analogous procedure to construct cross sections for inorganic phosphate and oxygenc The method used here for these two fields was less rigorous but also less time consum- ing,, The observed values of inorganic phosphate were written onto a cross section using depth and distance scales equivalent to those used in drawing the sigma~t section,, This sheet was then placed over the completed sigma-t section on the light table,, The isopleths were drawn as nearly as possible along the sigma-t surfaces, but not in violation of any of the observed values,, This was done in accordance with the principle used in isentropic analysis, namely,, that water flows along surfaces of constant potential density funder certain con« ditions rather generally encountered in the ocean' ; these surfaces being very nearly coincident with surfaces of constant sigma-to The same procedure was used in constructing the oxygen cross sections „ Neither inorganic phosphate nor oxygen is a conservative property, but proceeding as though they are probably leads to the most accurate cross sections possible in the absence of quantitative information about the biological processes. Some Results of Hugh M„ Smith Cruises 5 and 8 The station pattern for the June - August cruise of 1950, cruise 5, appears as figure 2 while that for the January = March cruise of 1951, cruise 8, is shown in figure 3. Each of these two cruises comprised primarily two lines of stations, one each along 158° W0 and 172 W0 Cruise 8 included additional stations along a zigzag course between 155° W0 and 169 W0 longitude The cross sections appearing as figures 4-32 are based on data collected along the four meridional station lines and stations 62-76 of cruise 8 along a NNE-SSW course (fig„ 3). Figures 4-10 re- sult from data collected along the station line 1-27 of Smith cruise 5 (figo 1), primarily along 172° W0 longitude These figures are in the sequence dynamic topography, geostrophic currents, BT, sigma-t, salinity, phosphate, and oxygen0 This sequence is repeated for each long line of stations on Smith cruises 5 and 8, except that the sigma-t, salinity, phosphate, and oxygen sections based on stations 28-51 of Smith cruise 5 appear elsewhere (Cromwell 1953) and are not repro- duced here Stations 27-61, on the zigzag portion of Smith cruise 8, are not represented by cross sections. Dynamic heights; Figures 4, 11, 14, 20;, and 26 show the smoothed profiles of isobaric surfaces with respect to the 1, 000- decibar surface,, The dots represent the actual results of dynamic computations and are plotted to show what liberties with the data have been taken in the smoothing process, Geostrophiccurrents; The relative currents, figures 5, 12, 15, 21, and 27, were computed from the smoothed profiles shown in figures 4, 11, 14, 20, and 26 respectively,, The isovels indicate the component of geostrophic flow perpendicular to the plane of the cross section,, They are not drawn between the 3-1/2° parallels be- cause flow close to the Equator is not even approximately geostrophic East currents are hatched,, The cross sections exhibit a complicated arrangement of zonal components of currents,, There is some uncertainty in the existence of the lesser flows, particularly in the narrow currents that are based on only two or three stations,, It is apparent, however, that there are appreciable regions of easterly flow existing outside the bounds of the Equatorial Countercurrent0 Table I is included to aid in identifying the currents that appear in the figures and to summarize pertinent information about them0 The positions to the nearest one-half degree of latitude of the surface boundaries of the Equatorial Counter cur rent were read from the figures of dynamic height,, The number listed under "Core of Countercurrent" is the latitude of the maximum speed through the plane of the traverse as read from the figures showing geostrophic current. Values within parentheses are uncertain,, Table I _... I . — — — — Southern Northern Longi - tude Figure numbers Dates of traverse boundary of Counter - current boundary of Counter - current Core of Counter- current 158°W0 11 and 12 Augo 1 = 2, 1950 5°N. 9°N, 7:i/2°N. 158°W0 14 and 15 Jan„ 19-22, 1951 2°N0 951/2°N„ (5-l/2°N 172°W0 4 and 5 July 7-9, 1950 (3-l/2°N„) 8 N. 6°N0 172°W0 26 and 27 Mar. 6-=8, 1951 4°N„ 10°No 5 = 1/2°N0 166°W„ 20 and 21 Feb. 12, 1951 5°N. -- 5-l/2°N„ Referring to figures 11 and 12, for example j the east-flowing Equatorial Countercurrent appears between 5 N„ and 9 Nc , with the North Equatorial Current immediately adjacent to the northc South of the southern boundary of the Countercurrent there is a major flow toward the west, the South Equatorial Current,, Since the currents near the Equator cannot be computed through use of the concept of the geostrophic current, the South Equatorial Current,, and in some cases the CountercurrentP is interrupted on the sections,. Bathythermograph sections: Temperature sections, using the bathythermograph data, are reproduced in figures 6, 13, 16, 22, and 28,, Two bathythermograph observations were made at each hydrographic station and additional lower ings were made between stations „ During cruise 5, BT casts were made at approximately 10-mile intervals,, During cruise 8, BT casts were made at approx- imately 20- to 30-mile intervals except for closer, 10-mile intervals between the Equator and 5° - 7 N0 The curve at the top of each bathythermograph section describes the surface temperature and was drawn using the bucket temperatures smoothed with reference to the continuous -recording thermograph,, In figure 6 between 5° 20' N0 and 10° 00" N„ , and in figure 28 between 17° 00' Nc and 18° 50' N„ „ the surface temperature is relatively high and varies irregularly,, This behavior is associated with light winds0 During the times that these irregularities occurred, the wind speed was predominantly Beaufort force 1 and calm0 In figure 13 the surface temperature changes abruptly near 4° 20' N„ This occurs at the surface intersection of the Equa- torial Front, a feature which is described in some detail elsewhere (Cromwell 1953)0 Sigma-t; In figures 7, 17, 23, and 29, the configuration of the sigma-t surfaces indicates relatively dense water in the surface layer near the Equator Q This is associated with the equatorial up- welling0 Nowhere else in the figure does the density of the surface layer indicate any appreciable addition of water from below,, The lines of constant sigma=t near the Equator bend down- ward in the lower part of, and just below, the thermocline„ In figure 6, for example, the isopleths of sigma-t = 26. 6_ through sigma-t - 27„ 0 exhibit pronounced local depth maxima at the Equator0 This feature appears in each of the sigma-t sections of this report, in the sections drawn by Cromwell (1953), and in the one by Montgomery (1954)„ It appears to be a prevalent feature of the central equatorial Pacific Salinity; The salinity cross sections are shown in figures 8, 18, 24, and 30„ Regions of salinity greater than 34.8 /oo are hatched. 7 Inorganic phosphates Two phosphate sections were drawn and appear as figures 9 and 31 „ In figure 9, there are large variations in the concentration of inorganic phosphate below the thermocline. "Pools" of high or low concentration appear almost at alternate sta- tions in the deeper water and often are found at stations where the concentrations in the surface layer are correspondingly high or low„ This suggests that these variations are not in the ocean, but arise fictitiously in the determinations 0 Surface water with a relatively high inorganic phosphate concentration appears near the Equator on both cross sections,, This prevalent feature of the central Pacific is associated with the equa- torial upwellingo Oxygen; Oxygen sections appear as figures 10, 19s 25, and 32„ Acknowledgements I wish to express my appreciation to Mary Lynne Godfrey, Richard V. Mead, and to those persons who worked with them in pro- cessing the physical data and plotting the sections,, Winifred Tseu carried out the chlorinity titrations and processed the chemical data, Tamotsu Nakata drafted the figures,, Thomas Sa Austin made helpful suggestions and assisted generously in the later stages of the work0 The scientific field party during cruise 5 was: Joseph E0 King (field party chief), Townsend Cromwell, Kenji Ego, Herbert Mann, Vernon Brock (Territorial Division of Fish and Game) and William Gosline (University of Hawaii),, During cruise 8 the field party was: Joseph Es King (field party chief), Herbert Mann, Richard Mead, Stanley Peterson, Isaac Ikehara and Walter Kawano0 There were many other persons who assisted in this work at sea and ashore and I gratefully acknowledge cheir contributions . LITERATURE CITED CROMWELL, T„ 1951 Mid-Pacific oceanography, January - March 1950o U„SL Fish and Wildlife Servc , Spec Sci„ Rep: Fish„ No0 54, 9 pp., 17figs0, 53 tables. 1953 Circulation in a meridional plane in the central equato= rial Pacific Jour3 of Mar, Res0, VolD 12, No. 2, pp0 196-213, 9 figs. LA FOND, E. C. 1951 Processing oceanographic data, H„ O0 Pub„ No0 614, 114 pp„ MONTGOMERY, RD B0 1954 Analysis of a Hugh Mc Smith oceanographic section from Honolulu southward across the Equator,, Accepted for publication in the Jour„ of Mar, Res., Vol0 13, No„ 1„ SNODGRASS, J„ Mc , D„ E„ CARRITT, and W, S„ WOOSTER 1953 An automatic servo-operated filter photometer, (In press), REMARKS ABOUT THE OCEANOGRAPHIC DATA Auxiliary station JJ_ata| Weather; Recorded according to the ww (present weather) code as it appears in the seventh edition of the U0 S, Weather Bureau Circular M, Instructions to Marine Meteorological Observers., Parts of this code are changed m the 8th edition of the Circular M now in use. Wind velocity; Measured using an anemometer located 30 ma above the sea surfaceD The observed direction is that from which the wind was blowing, given in degrees measured clockwise from north0 Tabulated data; The surface temperature was observed to the nearest tenth of a degree,, The hundredths digit appears always as a zero and has no significance,, On some stations, the "surface" Nansen bottle was lowered beneath the surface to avoid striking the side of the rolling vessel,, On these stations, the minimum recorded observed depth is that of this top bottle in the cast as no bucket sample was taken,, Paired protected thermometers were used at most depth»0 When the corrected values are 0o 05°Co or more in disagreement, the depth of observation is listed twice so that both temperature values may appear „ Pairs of determinations of inorganic phosphate concentra- tion were made for each sample. If the two values of extinction differ by more than „ 05 (i„e„ , by more than approximately „ 20 ug at/1) the depth of the sample is listed twice so that both values of inorganic phosphate concentration may appear,, Values enclosed within parentheses have been extrapolated to their designated depths,, Cruise 5: The surface temperature was measured using a bucket thermometer,, The thermometer used during cruise 5, stations 1 through 28, read . 2°C0 too low so that a + 02°C„ correction must be added to the values listed to obtain the correct surface temperature. A + S1°C= correction must be added to the surface temperature values listed for Smith cruise 5, stations 29 through 51„ 10 Cruise 8° Stations 3 and 5 were not occupied because of high winds,, During Smith cruise 8 the Nansen bottle that sampled at the seventh depth for which data are tabulated in this report did not always close properly« Although tabulated, the samples at this depth for stations 170 65, 66, 80, 82-87, 91, and 104-106 appear to have been contaminated during retrieval of the cast and were not used in drawing the cross sections of this report0 During cruise 8 a large number of observations of inor = ganic phosphate concentration were lost because the stannous chloride solution was improperly protected from exposure to the air and oxida- tion of the stannous ion occurred. Examination of the results, parti- cularly of the reagent blank values, indicate that the data of stations 1 through 76 are completely untrustworthy and so the values are de- leted from the tabulated data and a cross section appears only for stations 77-106o A + „ 1 C„ correction must be added to all the surface temperature values of Smith cruise 8„ 11 Figures Frontispiece; Attaching Nansen bottle aboard the Hugh M. Smith. 1„ Example of station data representation 2„ Station positions, Hugh M. Smith cruise 50 30 Station positions, Hugh Mc Smith cruise 8„ Cruise 5 - Hugh Mc Smith o 4„ Dynamic topography, 172 W0 50 Geostrophic currents, 172 WQ 60 Meridional section of temperature0 172 Wc 70 Meridional section of density, 172 W0 8„ Meridional section of salinity, 172 W0 90 Meridional section of phosphate, 172 W„ 10o Meridional section of oxygen, 172 W„ llc Dynamic topography, 158 WD 120 Geostrophic currents, 158 W„ 13. Meridional section of temperature, 158° W„ Cruise 8 - Hugh M. Smith 14„ Dynamic topography, 158 W0 150 Geostrophic currents, 158 W, 16D Meridional section of temperature, 158 W„ 17„ Meridional section of density, 158 W„ 180 Meridional section of salinity, 158 W0 190 Meridional section of oxygen, 158 W„ 20o Dynamic topography, 165 - 170 Wc o o 210 Geostrophic currents, 165 - 170 W0 o ° 22„ Vertical section of temperature, 165 -170 W„ 23„ Vertical section of density, 165° - 170° W. 24. Vertical section of salinity, 165 - 170 W. 250 Vertical section of oxygen, 165 - 170 W, 260 Dynamic topography, 172 W„ 27„ Geostrophic currents, 172 W. 12 28. Meridional section of temperature,, 172 W, 29. Meridional section of density, 172 W„ 30o Meridional section of salinity, 172 W. 31. Meridional section of phosphate, 172° W0 32. Meridional section of oxygen, 172 W„ 13 VESSEL ■SM/T'V STATION CRUISE B BT NUMBER _ ■ aT.Ti.mr //W/V nnTF ir.rT) J AH 19 J W TEMPERATURE VS DEPTH tONCHTUW /Sl'$S P TIMF fflfT) O'SO J-% CURVE .0* i 4 - i ■ 10" 12* \* • . i • 20* 2 r 2f &" 28s 3q°i. \ '-- * ■ A •' : • ■ ■ . :'T; , _. " -- - — • ' ■ ■ K > \ -. 1 - ^ i N ! \ IN \ i : , • ' ^ y > & / " ^^ . ■ ; / - „ • V -■ / • . \ . ■ / N i \ - - • • '. \ ■ \ ' ' ' \ \ \ \ N . ' ' I (X . \ / iS • Fig. l.~ Diagram used to represent temperature and salinity data. Points under an inverted V are the result of temperatures by reversing thermometers. Heavy- points are those read from the BT trace. Points inside a square are the result of salinity observations, plotted against temperature. Dashed lines indicate the paths to follow in relating temperature, salinity, and sigma-t to depth. Thus, in the diagram at adepthof 133meters the temperature is 15.28°C, the salinity, 34.49 °/oo, and the sigma-t, 25. 53 g/1. 180° 175° 170° 165* 160° 155° 150° • MIDWAY 1. uPEA \m RL a HE RUES *< IEEE tLISIANSXf 1 *LAYSAN A/ 25° ••MAROREEF 25° pinnaS.es / «r , v FRENCH FRIGATE SHOAL •NECKERI < < 3» *NIH0A 1 n> 20° 4» NIIHAU I ^KAUAI ^ ~0AHU \\ U0L0KAI SIS 0 C^fUUI S* 20° / \HAWAII 5» SO* 6» ■ JOHNSTON 1 49. . 8* AT 9» AC* 10* 45* 1 !• 44* 13* 14* IS* 42* 41* 40* ■ KINGMAN REEF 16* •PALUrRA 1 »• WASHINGTON 1 ie» Vanning i I9» 36* 20* 35* ^CHRISTMAS 1 21* 34* 23* 24» ' 32« 3I« •CANTON 1 25* -ENOERBURr 1 30* MKEAN /. *BtRNtE > 26 % THOENIX ■ ^ n~.«-fl -Wtt '* 'SIDNEY i. GARDNER /• 29* UALDEN 1 ■STAI 'BUCK 1 180* 175* 170° 165° 160° 155° 150° Fig. 2.-- Positions of hydrographic stations. Smith cruise 5, June - August 1950. 180° 175° 170° 165° 160° 155° I5( r 30° 25° 30° r 25° MOWAt / :>P£Ab R * 4 L a HERMES rP" ~ EEF ^ ' / •USmSI'".u>rSANl '1^0 REEF GARDNER «* PINNACLES / s , -„ FRENCH / frigate Shoal necker i *- NilHAU* ^ .OAMU C*i M0L0KAI 106* \%^':^tAU' <9 I05» 3. ^ 10 * JOHNSTON 1 , O 15° 15° I02« 4* 101. 6» I00» ?• 99» &• 5 96« 10* I I* 5° 9S» 94» •6 63»« .52 6\PALMTRA I 63» »5l 5° 93« 92» 65» -WASHINGTON* *59 *» «V^,t5# '5»39» 55# V9 <£»> 66* 58# »56 46» * I6» J8» •» #28 1 1 90» 67* •57 47. "• %CMSTMA?11 89* 68* 18* 87» 86» 70» 7I» JARVIS 20* 21* 5° It'KEi GARDNER N 1 .CANTON 85» .f/vflf 8IRNIE '• ■ tPH S4» «/tt ; - -5/OVi ffft//?)-; 72» 73» ■r / 22* 23« UALOEN 1 62* 75« •sa/ 25» 'BUCK 1 8,. 76» 26« 80* 10° 78* 15° 1 4 '- 15° 180° 175° 170° 165° 160° 155° 150° Fig. 3.-- Positions of hydrographic stations. Smith cruise 8, January - March 1951. ~i — i — i — i — I — i — i — i i i r i — r — r \ \ \ \\ \ / / // / / I I /III! \ \ \ \ 1 1 i l l i i i I l I I I I i_ 2 -J C 3 i-i O 5 o cd n] 0> CO u B 2 o tf> ° .1 °.sl " X V a) > C ■g 0 nl 3 % 2 u 3 » °" cu S u O nj u 5 2 u >. •s - C tu E o OffiepKiD irtfl" rOC\J SH313W OIWVNAQ ^ri.-\\ N io^-" ■ — 2 _l Si * 3 e X o ■r-l ffl •c a £ p. o E a o X U CO • c O u ir h CT" ^ ~^ 3 „ 'j rsl +j 'n rt ^ W 3 »-s • u ' V o DO b c 3 »-> •H a. * tj •# 3 4-> 0 ■£ en (J C " -I u — -ft X on a. «< o o ti n! ■*j »*< n h O 3 0J oi 00 o ^ ^ N O O I c o a, jj " "■ C o h o o g * c £ o w (SU313W) Hid3Q ^ X 00 . 2 rt 0..O nt O O 0 B a c £ c 01 lit I- (4 S 5 T1 h C •n rt M £ 3 h id C V 0 A ■ E V 4-* o V IT u CT o >-> JJ 3 < u U i m X vO S 3 f. ►n [fl dwai sowans (133d)Hld30 3 O o U > "3 00 c o 3 2 ^ h oo o c H ■$ .-a Jail 0; M c • o c; '■$ oo I oo' (SH313W) HldSO si D => o o o rj O m > h 3 o 4-1 c o U "3 c BO C in _0 "iS o "J- c 0 ft, +1 u OJ • » >- cV, eg >. ' *j — ' •|H o_ •5 8 2 ° CO 4-1 2 Si 5 w "(3 00 — B 3 m 0 "O w ." QJ l-t § I I § (Sa313W) Hld3Q I BO C O OO 5T 0 •0 r-' 4) rg > 1 o — o » m => 2 c K £ 2 < o rt c » 0 . XI ir> rt . h J 11 2 c ° ° -C J! E So o — 3 > S| 1 3 o2 « c o BO1-1 •H h (Sa313W) Hld3Q 19° 20* 21" 22* Fig. 11.-- Smoothed profiles of isobaric surfaces relative to the 1, 000-decibar sur- face along 158° W., July 28 - August 6, 1950. Points are the result of dynamic computations. Hugh M. Smith cruise 5, stations 28-51. Fig. 12.-- Zonal components of the geostrophic currents across 158° W. , July 28 - August 6, 1950. Computations based on smoothed profiles of isobaric surfaces (fig. 1 1). Current magnitude in cm/sec. East currents hatched. Hugh M. Smith cruise 5, stations 28-51. o £ 1 n: •n C 0 0 id > Tl X CO a j3 n! a BO n 0 P a 0) a, x V -d X 0) rt it -O o C ■g 0 c •o g> to *j m o fi p c 0 u. u 0 h > 0J t. a a; T3 TS C « e 3 II CD s 4-> V o^ u n) VH 3 sO 03 m 1 in > V o < < i h 1 oo u IM X f> >. *j — ' 3 E JJ. Hi U3 dW3i 3DVdans (13id)HJ.d30 Fig. 14.-- Smoothed profiles of isobaric surfaces relative to the 1, 000-decibar sur- face along 158 W. , January 15 - 26, 1951. Points are the result of dynamic computations. Hugh M. Smith cruise 8, stations 1-26. LATITUDE Fig. 15.-- Zonal components of the geostrophic currents across 158 W. , Janu- ary 15 - 26, 1951. Computations based on smoothed profiles of isobaric sur- faces (fig. 14). Current magnitude in cm/sec. East currents hatched. Hugh M. Smith cruise 8, stations 1-26. Q. 5 200 (U 400 600 700 800 900 LATITUDE Fig. 16.-- Above, surface temperature and below, temperature section based on bathythermograph data along 158° W. , January 15 - 26, 1951. Isotherms drawn at intervals of 5° F. Dots indicate depths of observations. Hugh M. Smith cruise 8. 2 500 O 600 t l i l l i l l l 1_ i I l 7° 6° 5° 4° 3° 2° l°S-0°-N 1° 2° 3° 4° 5° 6° 7° LATITUDE 9° 10° 11° 12° 13° 14° 15° Fig. 17.-- Meridional section showing the distribution of density (crt) along 158 W. , January 15 - 26, 1951. Contour interval 0.2 g/1. Hugh M. Smith cruise 8, sta- tions 1-26. O 600 J I I l_ J 1 I l_ J I L L J I I I L T 6" 5" 4» 3° 2° l°S-0°-N I" 2" 3* 4* 5° 6° 7" 8° 9* 10* ll» 12* 13* 14* 15* LATITUDE Fig. 18.-- Meridional salinity section along 158° W. , January 15 - 26, 1951. Con- tour interval 0.2 °/oo. Hugh M. Smith cruise 8, stations 1-26. I i T _> \.-- 3""fc. — r — r r 1 f — r 1 H S i J T' — TT^T r , • oc» • • • « \ • 8° 9° 10" II" 12° 13° 14° 15° LATITUDE Fig. 19.-- Meridional section showing the concentration of dissolved oxygen along 158° W., January 15 - 26, 1951. Contour interval 0.5 ml/1. Hugh M. Smith cruise 8. stations 1-26. — 300-- —500-- I I I I I I I II 7* 6° 5' 4° 3° 2° l°S-0"-N P 2" 3° 4° 5° 6° 7' Fig. 20. -- Smoothed profiles of isobaric surfaces relative to the 1, 000-decibar sur- face along a NNE-SSW line between 165° W. and 170° W. . February 12 - 16, 1951. Points are the result of dynamic computations. Hugh M. Smith cruise 8, stations 62-76. h 300 - 600 I" S-0°-N I*.' 2° 3° 4° 5" LATITUDE Fig. 21.-- Geostrophic currents across a NNE-SSW line between 165 W. and 170 W., February 12 - 16, 1951. Computations based on smoothed profiles of iso- baric surfaces (fig. 20). Current magnitude in cm/sec. East-southeast currents hatched. Hugh M. Smith cruise 8, stations 62-76. LATITUDE Fig. 22.-- Above, surface temperature and belov temperature section based on 2° W., Feb- ruary 12-18, 1951. Isotherms drawn at intervals of 5° F. Dots indicate depths of observations. bathythermograph data along a NNE-SSW line between 165°W. and 172° W. Hugh M. Smith cruise 8. 300 800 - 900 - _^ J L J L 6* 7* 6' 5° 4° 3° 2° l"S-0*-N 1* Z° 3° 4° 5' 6' T LATITUDE Fig. 23.-- Section showing the distribution of density ( ■"7 j-i So ■o ° _.' tl in O JS *' SJ ^2 SU313W OIWVNAQ t 1 r <3 3 X rt X w u M rt u a « (Tj 0) 3 -0 u 3 •° -H ,"> c In M <« : E * c d a> f*4 ^« r- h — 3 en U ■ 0 —. U vO O ? *> U qi " o 3 rt U VH ,, U a 3 j= « a u 2"S « o to X: ■ ' 0 0 00 -^ c o o r3 rfl ao 0 m C 0- ■ c ^ 0 « 0) tn 6 o o 2 3 t- « H U a) c -J C 0 0 tj £ CO n 1 rt 1 Xi s r-* « X M 0 3 X (Sy313W) Hld3Q S. J. J. 6° (5 (6 r- fw ra a; O *j XI C o Q " Ik M > 'J rt V C 0. ti id i c u -o u XI CD T3 c 0) rt E 4) n t, 3 M tt u 41 tli 0* ffS d X! M-l U 3 3 °° - ^ Ml M 3 -t-i c 0 T1 1 n h >h o; nj ^ c e o — 3 t •rl 3 h O >S C 2 o , o I rj — e-i in isy3i3w) Hidaa STATION i M/V Hugh M Smith; Cruise 5, 27 00'N; 175 ll'W, June 30, 1950 Messenger time: i955 GCT. Weaker: scattered clouds, cumulus and altostratus, 3-5 ft. Wire angle: 20° Wind: 050v •4 kt. Sea: OBSERVED DEPTH T S CTr D2 34e * '3 6 0.522 1.334 150 20.55 34.94 24.39 0.716 1.140 _ L6.41 34.66 0.067 0.939 ^50 12.20 3 4.30 26.03 0.935 0.871 300 10.10 34.34 2 6.44 i.078 3.776 40U 03.52 34.38 26.73 1.231 0.625 3UU 07.44 34.43 2 6.93 1.361 0.495 600 06.55 3 4.46 27.08 1.476 0.3S0 700 05.30 34.47 27.18 1.579 0.277 800 05.37 34.47 27.23 1.676 0.180 04.66 3 4.48 27.32 1.356 0.000 STATION 9 M/V Hugh M. Smith: Cruise 5, 13°00'NS 172°01'W, July 5, 1950. Messenger time: 2015 GCT« Weather overcast (with breaks), cumulus and altocumulus. Wind: 070°, 19 kt. Sea: 3-5 ft. Wire angle: 30° 0 DEPTH T 3 (m) (°C) (°/oo) 00 26. 20 34.65 09 26.42 34, 61 42 26,42 34. 61 < ■ "t 26, 43 34, 61 162 19,22 34,83 2 39 11.80 34. 38 J 17 09, 46 34. 49 481 07, 60 34.49 651 06,21 34,51 819 05, 18 34. 5 1 99 i 04, 48 34,5 1 1263 03, 66 34. 56 OBSE R V E D crt 22,73 22.63 22, 63 22, 63 24. 85 26, 16 26. 66 26.95 27. 16 27.29 27 37 27, 49 (ml/1). 4, 32 4. 75 4,79 4, 79 4 30 2. 30 0. 94 0.92 0. 84 i 19 1. 31 1. 60 PO4-P 40 32 30 31 58 I i 51 , 84 3,02 3, 00 2,98 3.05 0. 0, 0, 0. 0, 1 2 [NTE RPOLATED AND CALCULATED DEPTH T S . (i, C 0*474 600 06.78 34.53 27.10 1.332 0*364 700 06.00 34.52 27.19 1*434 0*262 800 05.32 34.52 27.28 1*527 0*169 1000 04.43 34.55 27*40 1.696 G.000 STATION 11 M/V Hugh M. Smith: Cruise 5, 11°03'N, 172°03,W, July 6, 1950. Messenger time: 1324 GCT. Weather: overcast (with breaks), no observation, 3-5 ft. Wire angle: 23° Wind: 060 , 20 kt. Sea: OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (Hg at/1) 00 26.80 3 4.65 2 2.54 4. 75 0. 34 09 27.04 34.6'J 22.45 4.69 0.27 42 27.10 34.67 22*46 4.71 0.25 82 26.99 34.69 22.51 4.69 0.26 159 15.91 3 4.50 2 5.46 3.70 0.88 234 10.66 34.40 26.39 1.63 2.15 309 09.32 34.58 26.76 0.60 2.54 460 07.63 34.56 27.00 0.61 2.32 610 06.26 34o5i 27.15 0.90 2.95 763 05.28 3 4.52 '_ 1 O La w 1.11 2.91 921 04.62 34.52 2 7.36 1.52 2.07 1137 03o82 3 4.56 27.48 1.7 0 2.93 INTERPOLATED and calculat: ED DEPTH T s o- t A D A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26*30 34.65 22.54 0.000 1.706 1C 27.04 3 4.63 2 2 . 4 5 0.054 1.652 20 27.06 34.64 2 2.45 0.13 8 1.593 30 27.08 34.65 22.45 0.162 1.544 5 0 27.03 34.68 22.47 0.270 i.436 75 27.01 34.6 2 2.50 0.405 1.301 1 rt *"> 25.06 34.03 23.22 0.531 1.175 150 16*30 34.65 2 3.31 0.716 0.990 203 12.50 34.37 26.02 0.035 0.071 250 10.20 34.5C 26.53 0.926 0.780 300 09.42 3 4.53 0 6.74 0.999 0.707 400 08.30 34.57 26. . I 1.129 0.577 500 07.27 3 4.54 27.04 1.246 0.460 600 06.37 34.51 27.14 1.332 0.354 700 05.63 34.52 2 7 0 ;: 4 It 449 c.;:5 7 CCO 05.12 34.52 2 7.30 1.539 0.167 1C00 04.36 34.53 27.40 1.706 o.ooo STATION 12 M/VHughM. Smith; Cruise 5. 09°54'N, L72°02»W, July 6, 1950o Messenger time; 2230 GCT. Weather: over- cast (with breaks), cumulus and stratocumulus. Wind: light and variable, 4 kt. Sea: < 1 ft. Wire angle: 03° OBSERVED DEPTH T S o- t O 7 PO4-P (m) (°C) (°/oo) (g/D (mf/l) (ugat/1) 00 26, 80 34. 56 22.47 4. 75 0.44 10 27. 12 34. 60 22.40 4. 69 0.46 50 270 10 34.63 22.43 4. 73 0.42 98 20.06 34.94 24.72 4. 73 0.53 196 11. 37 34. 61 26.42 0. 81 2. 16 292 09.80 34.67 26.75 0. 52 2.53 388 08.86 34.61 26.85 0. 54 2.72 581 06.78 34.51 27.08 0. 88 2.94 581 2.67 775 05.44 34.51 27.26 0. 87 3. 12 971 04.48 34. 52 27.37 1. 25 3.03 971 2.77 1168 03.74 34. 54 27.47 1. 53 20 71 1466 03.08 34. 56 27.55 2. 01 2.79 1466 2.43 INTERPOLATED AND CALCULATED DEPTH T S or t A D AD 1000- AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.80 34. 56 22.47 0. 000 1.609 10 27. 12 34.60 22.40 0. 054 1.555 20 27. 12 34.61 22.41 0. 109 1.501 30 27. 11 34.62 22.42 0. 163 1.446 50 27. 10 34. 63 22.43 0.272 1. 337 75 25.20 34.81 23. 16 0. 399 1.210 100 19.98 34. 93 24.73 0. 500 1. 110 150 12.90 34.40 25.97 0. 634 0.975 200 11. 30 34. 62 26.44 0. 728 0.882 250 10.42 34. 69 26.66 0.805 0.804 300 09.72 34.66 26.75 0.876 0.734 400 08.72 34. 60 26.87 1.008 0. 601 500 07.59 34. 54 26.99 1. 130 0.480 600 06.60 34. 51 27. 11 1. 241 0.368 700 05.91 34. 51 27.20 1. 343 0. 267 800 05. 32 34.51 27.27 1.437 0. 172 1000 04.38 34.52 27.39 1. 609 0.000 STATION 13 M/V Hugh M. Smith: Cruise 5, 08°54'N, 172°00'W, July 7, 1950. Messenger time: 0636 GCT. Weather: over- cast (with breaks), no observation. Wind: 180 Sea: 0. Wire angle: 20 12 kt. OBSERVED DEPTH T S 0- t 02 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ng at/1) 00 26.90 34.27 22.22 4.75 0.47 09 27.45 34.27 "5 *5 n ~ 4.68 0.33 46 27.35 3 4.45 .21 4.75 0.34 91 22.54 34.81 23.94 4.36 0.42 181 11*06 34.49 26.39 x * &a 2.27 271 09.93 3 4.63 26.69 0.54 2.63 362 09.02 3 4..' 2 6.31 0.46 2.20 543 07.34 34.52 2 7.01 0.55 3.03 724 05.72 3 4.4V 27.21 0.23 3.17 907 04.73 34.56 2 7.33 1.13 3.17 1092 04.04 3 4.54 2 7.44 1.36 3.14 1374 03.20 34.54 27.52 1.56 2.90 INTERPOLATED AND CALCULATED DEPTH T S 0- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.90 3 4.27 TO 0 ^ U . \j J 'J 1*637 Id 27.45 3 4.27 2 2.05 0.057 1.520 20 27.42 34.33 2 .10 0 • 1 1.5 I * 5 2 2 30 27.39 34.37 2 ..14 0.172 1.465 50 27.32 34.46 .23 0 ■ 2 8 5 1.352 75 26.60 3 4.59 0 . 422 1.215 100 20.36 3 4.33 24.46 0.533 1.104 150 1 -} ^ 1 3 4.41 26.11 0.669 0.96 8 200 10.30 34.57 26.50 0 * 7 0.279 250 10. 19 34.64 26*66 ..234 0.303 360 09.66 34.62 26.73 6*905 0.732 400 03.6 3 34.57 26*85 1.033 0.5 99 5 00 07.73 3 4.54 26.97 1.161 0.476 600 06.31 34.50 2 7.07 1.274 0.36 3 700 05.91 34.49 2 7.12 1. . 0.259 800 J5.23 34.53 27.30 1.471 0.166 1000 04.33 3 4.55 2 7.41 1.637 OoOOO STATION 14 M/V Hugh M. SmicA- Cruise 5, 08°00'N, 171°58'W, July 7, 195C. Messenger time: 1412 GCT. Weather: overcast (with breaks), no observation* Wind: calm. Sea: 0, Wire angle? 04 OBSERVED DEPTH T S 7 - 37 44 27.:.: 34.34 4.71 37 23. : 34.70 - . C » 172 n.92 34.: . «25 1.31 2. 255 09.86 3 4. bj 26.72 0. 2.52 333 09.09 34*63 2 6 . 3 3 0. ."06: 506 07.62 34.60 27.: - :597 2. " 677 06.24 34.56 :~e20 1.09 3. r5i .5.12 34.56 :_.33 1.36 3 . B : 1026 04.37 3 4.5S 2 7 • 4 3 1.57 3.-J2 1299 03.42 34.&S ~*53 1.67 3.14 INTERPOLATED AND CALCULATED DEPTH T $ a- t A D |A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 0 0 ::-i 34.33 1 J 2 >. * *> 0 yj 1.606 10 27.20 : . : .'.«!- 20 27.19 •-. 31 22.16 0.115 1.491 30 27.13 34.32 .17 0.172 1.434 5: 27cl2 • 26 _ 2 s 2 2 0... . le321 75 26.20 34.49 2? .61 0.422 1.1 100 21.02 3 4. .. 24.37 0.533 1.073 150 14.35 S4..-3 0.679 200 11.07 3^.60 26.47 0.776 .... 250 09.96 . 4.64 26. 552 75* 3c: • 41 34. .21 D. 400 c : • 5 7 24, .92 1.036 D.S 500 C7„70 34.60 27.02 1. 141 - 465 600 06. C5 34.57 ■37.1-; .36 700 1. 07 2v« 0*2^6 05.40 34.56 27.30 1.442 0.1 1000 C4.43 34*58 2 7.43 a r O J 3 9 JUL STATION 16 M/V Hugh M. Smith; Cruise 5, 06°02'N, 171°56'W9 July 8, 1950. Messenger time: 0719 GCT. Weather: broken clouds, no observation. Winds calm. Sea: 0. Wire angle: 30° OBSERVED DEPTH T S (T t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (HLg at/1) 00 28*20 34.31 22.21 4.73 0.22 09 27.72 34.72 22.30 4.63 0.27 43 27.74 34.97 22.43 4.66 0.35 85 26.40 34.99 22.92 4.30 0.40 165 12.68 34.54 26.12 1.79 1.71 245 10.07 34.69 26.72 0.77 2.22 325 09.41 34.67 26.31 1.06 2.16 435 08.12 34.53 26.95 0.33 2.46 649 06.53 34.52 2 7.13 0.99 2.49 818 05.26 34.54 27.30 1. 33 2.75 994 04.44 34.54 27.40 1.54 2.70 1273 03.43 34.60 2 7.54 1.92 2.69 [INTERPOLATED AND CALCULAT1 ED DEPTH T $ 0- t A D A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 60 28*20 3 4.31 00 0 i 0.000 1.651 10 2^.72 34.72 22.30 0.056 1*595 20 27.72 34»86 22.35 0.111 1.540 30 27.74 3 4* 38 2 2*41 5. 166 1.435 50 27.71 34.98 22.50 0.274 1.377 75 27.40 34.99 22.60 0.407 1.244 100 23*20 34.94 23.35 0.525 1 . 126 150 13.70 34.55 25.92 0.631 0.970 200 11.10 34.65 26.50 0.773 0.878 250 10.03 34.68 2 6.72 0.343 0.803 300 09.60 34.67 26.73 0.916 0.735 400 08.83 34.62 26*87 1.046 0.605 500 08.00 34.57 26.96 1.169 0.4:2 600 07.07 34.54 27.07 1.234 0.367 700 06.14 34.53 27.18 1.333 0.263 800 05.38 34.54 27.29 1.432 0.169 100G 04,45 34.54 2 7.39 1.651 0.000 STATION 17 M/V Hugh M. Smith: Cruise 5, 05°00,N, 172°02'W, July 8, 1950. Messenger time: first cast, 1700 GCT; second cast, 1817 GCT. Weather: broken clouds, cumulus and altocumulus. Wind: calm. Sea: 0, Wire angle: first cast, 0°: second cast, 0° OBSERVED DEPTH T s (T t °2 PO4-P (m) (°C) (°/oo) (g/U (ml/1) 1 (ng at/1) 00 27.30 34.70 2 2.26 4 . 5 5 0.35 10 27*90 34.70 22.22 4 3 67 0.33 50 27.7 2 3 4.74 2 2.29 4.69 0.34 100 26*30 35.21 4.05 0.72 198 11.14 34.65 26.50 0.S5 2.43 294 09.04 3 4.65 26.86 1.70 2.51 389 08.46 34*63 2 6.93 1.73 2.51 5, 1 07.22 34.58 27. 1.30 2.37 772 05*74 34.52 27.23 l«3n 3.07 965 0 4.51 34.54 27.39 1.54 3.10 1160 03.81 34.56 27.43 1.79 3*07 1469 03.03 34.56 27.55 2*03 3.00 1955 02.37 3 4.61 27.65 2.36 2.31 2 441 01*90 3 4.65 27.72 2.72 2.52 2926 01.69 3 4.65 27.74 3.0 5 2.55 3413 01.56 3 4 • 6 1 2 7 . 7 .1 3 . 1 8 2.52 [INTERPOLATED AND CALCULAT1 ED DEPTH T s 1.4 0.26 3 COO 05.57 34.52 27.25 1.535 0.171 1000 04.35 34.55 2 7 • 4 1 1.706 0.220 STATION 13 M/V Hugh M. Smith; Cruise 5S 04°00'N, m°03'W, July 9, 1950o Messenger time: 0324 GCT„ Weather: scattered clouds, cumulus. Wind; 020°, 9 kt. Sea: < 1 ft. Wire i no angle: 0 OBSERVED DEPTH T S 0.937 0.247 300 11.78 3 4. 26.^2 1 • 0 2 1 0.764 400 09.61 34.70 2 6 . a 0 1.168 0.616 500 08.00 3 4.62 27.00 1.294 0.49 0 6 00 06.92 3 4.57 2 7.10 1.406 0.379 7 00 06.27 34.54 27.18 1.509 0.275 800 05.63 34.52 2 7.24 1.607 0.173 1000 04.75 34.55 27.37 1.72 4 0.000 1/ Looks improbable on Temperature-Depth and T-S curves. Bottom three bottles may have pretripped. STATION 22 M/V Hugh M. Smith: Cruise 5, 00°08'S, 172°01fV7, July 10, 1950. Messenger time: 1201 GCT. Weather: broken clouds, no observation. Wire angle: 28 Wind: 160 , 11 kt. Sea: 1-3 ft. OBSERVED DEPTH T S cr t o2 PO4-P (m) (°C) (°/oo) (8/D (ml/1) (Hg at/1) 00 26.30 35.37 23.02 4.75 0.47 09 26. S7 35.37 23.06 4.69 0.54 44 26.64 35.37 2 3.13 4 s 65 0.52 83 26.21 35.41 23.2? 4. AG 0.58 178 19.10 35.34 25.27 3a 13 0.96 272 12.63 3 4.90 2 6.41 3.17 1.43 367 10.54 3 4 o 7 4 26.67 1.75 2.06 561 07.35 34.52 27.01 1.81 2.35 756 06.06 34.51 27.18 1.84 2.54 951 04.82 3 4.i9 27.32 2.0 8 2.51 951 2.76 1148 04.00 34o51 2.24 2.40 1430 03.08 34.58 2 7.56 2.24 2.46 INTERPOLATED AND CALCULAT1 ED DEPTH T s cr t A D A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.80 35.37 23.06 0.000 1.807 10 26.86 3 5.37 23.06 0.048 1.759 20 ■ »34 35.37 23.07 0.096 1.711 30 26.79 35.37 23.08 0.144 1.663 50 26.61 35.38 2 3.15 O.240 1.567 75 26.36 3 5.41 23.25 0. 35 3 1.449 100 26.13 35.41 23.32 0.474 1.333 150 22.-12 35.IS 24.34 0.630 1.127 200 16.60 35.19 25.77 0.829 C«97.f. 250 13.60 34.96 • 26 0.932 0.875 300 12.01 3 4.-, 35 26.49 1.019 0«738 400 0^.90 3^.69 26.75 1.169 0.633 500 08.17 34.55 26.92 1.301 0.506 600 07.02 34.52 27.06 1*418 0.. 700 06.40 34e52 27.14 1.525 0.202 800 C5.79 34.50 27,21 1.625 0.132 1000 04.64 3 4.50 27.34 1.307 0o000 STATION 2 3 M/V Hugh M Sm^th: Cruise 5, O^OO'S, 171°57rW, July Messenger time: 1950 GCT, Weather; scattered 10, 1950. clouds cumulus angle: 31 Wind: 120 , 15 kt. Sea. 1-3 ft, Wire OBSERVED DEPTH (m) T (°C) . f°/oo) i - • 1 --, 0 * 7 .i. 0 1 a 200 19.93 .5 3 . 1 x *. 5 * ;> j 0.9 05 .900 250 12.00 3 4. '. J ■ ' 1 i 0 • j a j. * C 1 2 0.793 300 10.35 34.73 2 6.74 ilOu^ 400 03.92 34.07 2 6.33 1 0*539 5 00 07.76 34.60 1*335 0*470 600 06.73 34.54 27*11 1 . 443 0. 360 700 05.73 34.51 27.21 1 . 5-+6 0.259 000 05.12 34*51 27*29 1.637 0*160 1000 04.40 34.5.1 2 7*32 l.o 0 3 3.000 STATION 26 M/V Hugh M. Smith: Cruise 5, 04°05'S, 171°56'W, July 11, 195C. Messenger time: 2117 GCT. Weather: scattered clouds, cumulus. Wind: no observation,, Sea: 1-3 ft. Wire angle: 15 OBSERVED DEPTH T S 1.235 0.575 5 00 07.60 3 4.61 2 / . .. 1 2 1.355 0.455 600 06.70 34.56 27.13 1.463 0.347 700 05.7 2 34.56 2 7.25 1.561 0.249 8O0 05. 34 54.54 2 7.33 U649 0.161 1300 34. 21 34.54 27.*2 1.310 0 t.O 0 0 STATION 27 M/V Hugh M. Smith: Cruise 5, 05°04'S, 171°58'W, July 12, 1950, Messenger time: first cast, 0522 GCT; second cast, 0636 GCT. Weather: scattered clouds, no observa- tion. Wind: 100°, 9 kt. Sea: 1-3 ft. Wire angle: first cast, 30 ; second cast, 40 OBSERVED DEPTH T S (Ft °Z PO4-P (m) (°C) (°/oo) (g/1) (ml/1) (v-g at/1) 00 27.90 35.79 4.63 1/ 09 2 7,36 35.70 22c 4.64 43 2 7*63 3 5.63 2 3.03 4.69 35 27.66 35*70 2 3.05 4.67 168 24.98 3 5.97 24.10 3.90 247 15.10 35.19 26.12 2.36 324 10.42 3 4.73 26.73 2.03 43 0 03.14 34.63 26r 1.73 639 06.60 3 4.54 27.13 2.15 S06 05.29 3 4.51 27.2 2.52 986 04*46 3 4.54 2 7.39 2.51 1162 'H 03.37 35.21 27.9 9 3.30 1611 ?/ 02.76 34.61 2 7.62 2.76 2072 02.14 34.63 2 7.68 2.93 2537 01.31 3 4.63 27.71 3.16 343 0 01.49 34.67 27.77 3.69 INTERPOLATED AND CALCULAT] ED DEPTH T s o- t A D A D10OO- A D (ml (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 06 27.90 35. h) diiUH u » u u u 1.32 / 10 27.25 3 5,69 22.93 3.0 49 1.778 20 27. 30 35.69 2 3-0 0 0.09 3 1.729 30 2 7*75 35.63 2 3.01 0.146 1.621 50 27.63 35.70 23.05 0.244 1.583 75 27.67 35.70 23.05 0.365 l.<+62 100 27.62 35.71 23.07 0.436 1.341 150 25.66 3 5 . 9 0 23.84 0.711 1.116 2 00 20.45 35.30 25.27 0. 0.943 250 14.90 35.13 ,15 1.002 0.325 300 11.60 34.37 2 6.5 3 1*029 0.733 400 09 • 0 2 34.63 23.37 1.229 3.593 500 07, 96 3 4 . 6 1 26. 1.350 0.477 600 06.99 34e56 27t09 1*462 0.365 700 06.07 3 4 • 27« lo64 0.263 800 05.35 34.52 2 7.22 1.553 0.169 1000 04.40 34.54 2 7.40 1*827 \J • ^ \J V 1/ Photometer not operating properly. 2/ Only the temperature at this depth appears reasonable,, Other values suggest that the Nansen bottle sample was contaminated through leakage on the way up. 3/ Depth not reliable. STATION 28 M/V Hugh M. Smith; Cruise 5, 04°59'S, 158°03'W, July 28, 1950. Messenger time: first cast, 1349 GCT; second cast, 1449 GCT. Weather: broken clouds, cumulus. Wind: 110 14 kt. Sea: 3 = 5 ft. Wire angle: first cast, 35 ; second cast. 35° OBSERVED DEPTH T S »30 35.48 2 3.32 4.66 84 26*04 3 5.46 2 3.39 4*54 169 16.20 35.32 25*96 2 « 6 3 259 12.18 34.38 2 6.48 2.94 351 10.71 34.79 26.68 1.73 539 07.54 34.53 27.03 1.55 723 06.24 34.52 27.16 1.70 919 05.00 34.52 27.32 2.04 1111 04.20 34o54 27.42 2.05 1402 03.24 34.53 27.55 2. 13 INTERPOLATED AND CALCULAT] ED DEPTH T s o- t A D A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26-30 35.48 2 3.32 0.0 CO 1.66 3 10 26.32 35.46 23.30 0*046 1.617 20 26.31 35.47 2 3.31 0.092 1.571 30 26*30 35.48 23.32 0.137 1.526 50 26.28 3 5.43 23.33 0.229 1.434 75 26. 13 35.47 23.37 0.343 1.320 100 25.10 35 9 47 23.69 0.433 1.210 150 18*43 3 5.47 25.54 Q-622 1*041 200 13.56 35.01 26.30 0.729 0.934 250 12.31 3 4.90 26.47 0.S15 0.84S 300 .11.57 34.G4 26.57 C.C94 0.769 400 09.81 34.74 26.80 1.0 39 0.624 500 08.12 34.62 26.98 1.165 0.49 3 600 06.99 34.54 27.03 1.273 0.385 700 06.39 34.52 27.14 1.3 4 0.279 300 05.80 34.52 27.22 1.483 0.130 1030 0 4,71 34*53 37c36 1*663 0.000 1/ Photometer not operating properly. STATION 33 Cruise 5, 00°02,S, 157°58'W, July Messenger time: 0850 GCT„ Weather: M/V Hugh M. Smith 30, 1950 scattered clouds, cumulus 3-5 ft. Wire angle: 41° Wind: 100 , 18 kt. Sea: OBSERVED DEPTH T S cr t OZ PO4. P (m) (°< 3) (% 30) (g/1) (ml/1) (M-g at /I) 00 25a 70 35. 39 2 3 * 4 4 4*64 1/ 03 25. 34 35. 37 23» 38 4.58 ~ 33 25. 34 35. 37 23*38 4,53 76 25. 70 35. 37 23*43 4.43 153 13. 93 35. 30 25.28 3.28 237 12. 81 34. 92 26*39 3.12 329 11. 22 34. 83 26.62 2*10 518 07. 72 34. 61 27.03 1.57 70S 06. IS 34. 56 27*20 1.74 697 05. 25 3 4. 52 27*29 1.99 1083 04. 16 34. 54 2 7.43 2.04 1378 03* 26 34. 63 27*59 2.11 INTERPOLATED AND CALCULAT] CD DEPTH T s 4.43 137 20« 12 3 4. 90 24.67 3.22 215 13. 12 3 4. 96 26.36 3.13 299 10. 85 3 4o 83 26*69 2.01 476 OS. 46 34a 69 2 6.98 1.28 659 06a 38 34» 58 27.19 1.63 844 05. 45 34. 5 4 27.2 8 1.92 1030 04. 42 34. 56 27o41 2.03 1316 03e 38 34. 5 8 27.53 2.01 [NTERPOLATED AND CALCULAT] ED DEPTH T ^3 (°/ooi (gm/l) I dyn„ m) idyn. m^ 00 26 30 35.28 2 3 17 0 000 1. 652 10 26. 39 35, 22 2 3, 10 0.047 1. 605 20 26 32 35.21 23. 11 0.095 1. 557 30 26.26 35.21 23, 13 0. 143 1,509 SO 26. 18 35.22 2 3 16 0.2 38 1,414 75 26.05 35.23 2 3,21 0. 356 1,296 100 25. 81 35.22 2 3,28 0.473 1. 179 150 18,25 34 86 25, 12 0, 661 0.991 200 11. 88 34 87 26. 53 0.773 0,879 250 11. 00 34.83 26.66 0. 848 0 804 300 10.55 34 80 26.72 0.919 0.733 400 09. 55 34 7 3 26. 84 1.055 0.597 500 08.25 34,66 26, 99 1. 178 0 474 600 06.91 34,60 27, 14 1.288 0. 364 700 06. 34 34 59 27,21 1 388 0,264 800 05. 82 34 58 27.27 1.483 0. 169 1000 04, 50 34.58 27.42 1 652 0. 000 1/ Bottle may have pretrtpped STATION 36 M/V Hugh R Smith: Cruise 5, 03°00'N, 157°58'W, July 31, 1950. Messenger time: 0932 GCT„ Weather: scattered clouds, cumulus. Wind: 100 , 17 kt. Sea: 3-5 ft. Wire angle: 42° OBSERVED DEPTH T S <7 t o2 P04-P (m) (°C) (°/oo) (g/1) (ml/1) (ugat/1) 00 26. 10 35, 30 23.25 4. 77 0, 6S 07 26.30 35,25 23. 15 4.75 0.66 38 26.22 35.25 23. 17 4. 75 0.68 73 26. 01 35,23 23, 22 4. 72 0.69 140 23.83 35, 16 23.83 3,85 0.82 200 10.88 34, 74 26.61 2.69 1.89 262 10,43 34. 78 26.73 1. 78 2. 18 400 09.53 34. 69 26.81 1. 62 2.28 542 07,98 34.60 26,98 1.27 2.64 690 06.40 34. 52 27. 14 1, 60 2.69 849 05.30 34, 54 27. 30 1, 78 2.90 1114 04.00 34.56 27.46 1. 86 2.87 I NTERPOLATED AND CALCULATED DEPTH T S o- t AD AD 1000- AD (m) <°C) (°/oo) (gm/1) (dyn, m) (dyn. m) 00 26. 10 35.30 23. 25 0. 000 1.733 10 26,29 35.25 23. 15 0. 047 1.686 20 26.27 35.25 23. 16 0. 094 1. 639 30 26.23 35,25 23. 17 0. 142 1.592 50 26. 14 35.24 23. 19 0. 236 1,497 75 26.00 35.23 23.23 0. 353 1. 380 100 25.92 35.22 23. 25 0.471 1. 262 150 23.62 35.09 23.84 0, 692 1 . 04 1 200 10.88 34. 74 26. 61 0. 833 0.900 250 10.43 34,73 26.73 0.905 0.829 300 10. 31 34.78 26. 75 0. 974 0.759 400 09.53 34. 69 26.81 1. 110 0. 623 500 08.44 34,63 26.93 1.238 0.495 600 07. 31 34.56 27.05 1. 356 0. 378 700 06. 30 34.52 27. 16 1.463 0. 270 800 05. 60 34.53 27.25 1,561 0. 172 1000 04.41 34. 56 27.41 1, 733 0.000 STATION 37 M/V Hugh Mo Smith; Cruise 5, 04°02'N0 158°03'W0 July 31, 1950„ Messenger times 1712 GCTU Weather: scattered clouds 8 cumulus and altocumulus 0 Wind; 090°, 13ktQ Sea: 3-5 ft0 Wire angle; 40° OBSER VED ■' DEPTH T S -■ '. r\ J- : if - i v 34.72 . '1 ~ 3.29 1.17 2 2 - 1 1 . ', : <■ 6 7 2 & « 4 4 1.15 2.2'; 09.90 34.67 26.73 0.5S 2.70 i : r. r i_ - 03.3£ 3 4.61 2 6 e 9 3 6.95 2.9: c n 0 ' » 1 2 .54 2 7 « 0 6 0371 3*17 796 05.70 3 4*54 2 7*25 1.02 3.23 97 3 6 4 e 4 S 3 4*5 4 r 7 . 3 9 1 »45 3 • 2 8 1258J,/ 34.61 INTERPOLATED AND CALCULAT1 ED DEPTH T 3^ o- t A D A D1000 -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 27*30 3 4 • C 3 2 2 * 5 5 0.000 3. .76 7 10 27* 44 34. 2?.47 0 .053 1.714 20 27«44 34. >.47 0.107 1.660 30 27.44 3 4.83 -47 0.3.61 1.606 50 ?7-44 34, 33 2 2,47 0.269 1*493 75 26e72 34.92 22.77 0 « 40 1 1.366 100 2 5 » 5 0 35 .Of- 2 3.2 5 0.523 1.244 3 50 19.-75 34.30 2 4.69 C.723 1.044 200 13.0 5 3 4 . ft 5 • 1 3 0.854 0.913 250 11.25 34c 2 6.50 0.943 0.824 300 10o07 3 4.( 6.71 3 . C 0.749 400 08.89 3 4.64 " 6 . 7 1 . 1. 5 ] 0 . 6 1 6 5 00 08.07 34.59 2 6*96 1*274 0.49 3 600 0-32 34.55 27.04 3. .39 0 0.377 700 06s 50 3 4 r 5 3 2 7.14 ] -4.9'"! 0.269 8 0 0 05.65 34.54 2 7 t 2 5 1.596 0.171 1000 04= 33 ^-4e54 2 7 e 4 1 1.767 0.000 1/ Bottle probably pretripped. STATION 4_ M/V Hugh M. Smith: Cruise 5, 07°00'N, 157Q57'W August 1, 1950. Messenger time; 1927 GCT„ Weather; scattered clouds, cumulus. Wind: ICO , 17 kt. Sea; 1-3 ft. Wire angle: 32° OBSERVED DEPTH T S (T t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (Hg at/1) 00 27.40 34.92 22.55 4. 65 0.52 09 27.49 34.90 22.51 4.63 0 .46 42 27*50 34.90 22*50 <+a66 0.41 84 27.46 34o94 2 2 . 5 5 4.63 0.48 164 14.17 34.61 25.87 1.97 1.70 242 10.53 34.72 26. b6 0.63 2.34 320 09.55 34.69 26.80 0.72 2.57 479 03.18 34.61 26.96 0.95 2.74 640 56.69 34.54 27.12 0.50 3.13 802 05.34 34.52 27.28 0.78 3.06 971 04.64 34.54. 27.37 1.35 3.09 1245 03.64 34,56 27.49 1.60 3.17 [NTERPOLATED AND CALCULAT] ED DEPTH T s 0- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) uO 2/.4U 34.92 Z 00 27.70 3 4.43 22.09 0.000 1.605 10 27.77 3 4.35 22o00 0.053 1»547 20 27.73 34.36 ^•02 0. 1x6 1.43 9 30 27.68 34.37 22.05 0. 174 1.431 50 27.53 3 4.51 22.18 0 o 2 3 9 1.316 75 26.05 34.93 2 2.:- 9 0.421 1.184 100 19.45 34.64 24.65 0.524 1.. 150 12.75 3 4.49 26.07 0.658 J. 947 200 10.73 34.66 26.58 0.743 0.860 25 0 10.04 3 4.63 26.71 0. 0.737 300 09*63 34.69 26.79 C.386 0.719 400 08.68 34.63 26.92 1.013 0.592 500 07.63 3 4.53 27.01 1. 131 0.474 600 06. 34.54 27.10 1.241 0.364 7 00 06.01 34.52 27.19 1 .34^ 0.262 800 05*40 34.54 27.29 1.4 3 7 0.168 IC00 04.52 34.56 27.40 1.605 0.000 1/ Sample bottle broken. STATION 42 M/V Hugh M. Smith: Cruise 5, 09°00'N, 157°55'W, Messenger time: 1051 GCT< August 2, 1950 showers of rain, no observation Sea: 1-3 ft. Wire angle: 10° Wind: 130 Weather: 12 kt. OBSERVED DEPTH T S or t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) ("g at/1) 00 27.00 34.31 bLlhli 4.67 0.41 09 27.15 34.23 2 2.11 4.65 0.38 49 26.83 34.36 22.30 4,72 0.37 97 14.22 34.33 25.64 3.03 1.16 194 10.29 34.63 26.63 0.44 2.39 290 09.45 34.61 26.76 0.47 2.44 385 08.38 3^.56 26.59 0.66 2.64 574 06.53 34*51 27.11 0*56 2.87 765 05.40 34.52 27.27 0.73 2.99 955 04.42 34.52 27.38 1.01 2.87 1147 03 #88 3 4.54 27.45 1.29 2.94 1440 03.22 34.52 27.50 1*26 2.92 INTERPOLATED AND CALCULAT] ED DEPTH T S 2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ng at/1) 0-0 2 6 o 1 0 34.69 TO ,70 L_ 4.. t> ' ..' 4.70 0.36 1C 26*33 3 ^.67 22.70 4.76 C.33 4v 2 6 • 3 2 34*63 21.67 4.81 0.32 97 23.08 34.99 2 3 • 9 3 5*22 0.27 192 13*44 34. 33 25*60 3*22 1.19 257 1 0 • 28 3 4.54 26.56 0.79 2.46 382 09.20 34*56 26.76 0 * 46 2.43 574 0 + • 1 o 34*51 27.03 0.62 2*73 766 03.62 3 4.49 2 7.22 0.73 2.92 960 04.~2 34.51 2 7.34 0.64 3*12 12.56 03.99 j'ts; -r 27e4s 1.27 2.95 1450" 03o 26 3 4*60 2 7.56 1.5 6 3.06 1942 C 2 . 3 1 3 4*61 27*65 2.04 2 .67 1942 2.89 2*36 01.91 34*65 2 7. 7 t. 4. 0 3 Z 2.57 2934 01.75 34.67 27*75 2.76 2.43 A H -. O .. .i.i J A.5J •34nfS7 ? 7 * 7 6 . ft .1 »■ 2*44 INTERPOLATED AND CALCULAT] ED DEPTH T S o- t A D A D10OO- A D (m) (°CJ (°/oo) (gm/i) (dyn. m) (dyn. m) 00 26.10 34*69 2 2 9 7 9 0.000 1 • 74 S 10 2o . 33 3 4*67 22* 7 0 0.051 1.697 20 26*33 34.6b 22.70 0. 103 1*645 30 26.33 34.65 22*69 0.155 1.593 50 2o.31 34*63 22.68 0.259 1.489 75 26.20 3 4. b3 2 2 0 7 1 0o339 I 9 339 100 ^2.90 35.01 23*99 0.503 1*245 150 ■ 13.81 34*86 24.98 0.679 1.069 200 12.58 34.. 34 25.98 0.808 0.940 250 10.51 34.53 26.52 0.900 0.648 300 10.19 34*54 26.5 3 0.979 0.769 400 06.98 34.56 26*80 1*123 0.625 500 07.90 34.54 26*95 1.250 0.493 600 06.92 34.31 27.07 x e 366 0.332 700 06.06 34.4V 27. 16 1.472 0.276 800 05.40 3 4.4V 27.25 1 0 5 b v 0*179 1000 04,62 3 4 0 5 1 27.35 1 9 7 " 8 0. 00 0 STATION 49 M/V Hugh M. Smith: Cruise 5, 17°00'N, 158°08'W, August 5, 1950. Messenger time: 0412 GCT„ Weather: broken clouds, cumulus, altostratus and cirrus. Wind: 080 17 kt. Sea: 3-5 ft. Wire angle: 30 OBSERVED DEPTH T S 0" t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (M-g at/1) 00 25.60 34.21 23.04 4.82 0.46 08 25.78 3 4.79 22.96 4 • 8 5 0.26 44 25.67 34.79 22.99 4.90 0.26 87 24.76 3 4.70 23.27 5.00 0.29 171 20.74 35.14 24.69 4,75 0.35 25 3 14*02 34.40 2 5.74 4,07 0.97 332 09.70 3 4.12 26.38 2.99 1.94 493 06.79 34.31 26.93 0.97 2.87 656 05.54 34.36 £. 1 • X 2 0.34 3. 03 023 04.82 34.42 2 7.26 0.93 3.13 999 04.20 34.49 27.35 1.16 3.16 1279 03.40 34.52 27.43 1,40 3*11 :nterpc HATED AND CALCULATED DEPTH t S 0" t A D A D10OO- A D (m) (°C) (°/oo) (WD (dyn. m) (dyn. m) 00 25460 3 4.31 2 3.04 0.000 X . O Q .' 10 25*73 3 4479 2_«96 0.049 1.818 20 25.76 3 4.79 2 2.97 0,092 1.769 30 25.73 3 4.79 .93 0.147 1.720 50 25.66 34*79 2 3 c C 0 0.245 1 0 622 75 25.01 3 4 . 7 -1 23el9 0.365 1.502 100 24.25 3 4.80 2 3.44 0.480 1.387 150 2 i o 66 35.18 24.47 0.631 1,186 200 18.82 3 4.96 25.06 0,844 1.023 256 14.26 34.42 25.72 0.977 0.390 300 11.63 34cl3 26.15 1.004 0.723 400 08.08 34.30 26.73 1.251 0.616 500 06.70 34.32 26.95 1.330 0.427 600 05 • 95 34. 34 27.06 1,494 0,373 7 00 05.31 34.37 27.16 1.593 0,269 800 0 4.89 34.41 27.24 1.694 0.173 1000 04.19 3 4 » 4? 2 7.33 1,367 cooo STATION 50 M/V Hugh M. Smith: Cruise 5, 19°02'N. 157°59'W„ August 5, 1950. Messenger time: 2035 GCT0 Weather: broken clouds, cumulus, altocumulus and altostratus. Wind: C50°, 14 kt. Sea: 1-3 ft. Wire angle: 03° OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (Hg at/1) CO 25.90 34.72 -s ^ ^ "7 c u 9 O t 4*03 0.31 10 26.12 34.70 2 2 o 7 9 4<>35 0.26 5 0 25o30 34.72 23.06 5.04 C.23 99 22.37 3 5 * 1 2 24.08 4o97 0.24 196 13.96 34.95 25.02 4.54 0.40 292 11.60 3 4.18 26.05 4.09 1.17 33S 08.02 3 4.09 2 6.53 2.56 2.11 5 20 05.70 34.25 27.02 6.34 2.61 774 04*86 3 4 « 3 3 I- i 0 4 I. 6.92 2.57 967 04.22 34.47 2 f o 3o 1,10 2.77 1161 03.66 3 4.49 27.44 1.25 2.66 1455 02.35 3 4.49 27.51 1 o 53 2.^5 INTERPOLATED AND CALCULATED DEPTH T S o- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) CO 25.90 34.72 n n --N n W 0 W V w 1..85.S 10 26.12 34*70 2 2 » 7 9 0.050 It 308 20 26.05 34.70 55.Q1 0.101 1.737 30 26c01 34.70 2 2.3 3 0.152 1.706 50 25.30 34.72 23.06 0.251 1.607 75 23.70 34.97 2 3.73 0.36 4 1*494 loo 22*82 35.12 24*10 0*464 1.394 15 0 20.56 35.12 24.72 0*643 1.215 200 13.31 34.94 25.04 0.300 1.052 256 16.25 34.64 25.43 0.9 41 0.917 300 11.22 34*16 26.10 1*056 0.302 46o 07*82 34.09 26.61 1.231 0a627 500 06.32 34.17 26o 1.369 0*439 600 05.59 34.27 27.65 1 • 4 6.372 700 05.13 34.33 27.15 1*591 0.267 300 04.73 3 4.40 27.25 1.637 0.171 10 00 04.10 34.43 27e33 1 « 8 5 B 0.000 STATION 51 M/V Hugh M. Smith; Cruise 5, 20°53'N, 158°02'We August 6, 1950. Messenger time: 0930 GCT„ Weather: scattered clouds, no observation. Wind; 060 , 19 kt„ Sea: 3-5 ft. Wire angle: 25° OBSERVED DEPTH T S o-t 02 po4-p (m) (°C) (°/oo) (g/1) (ml/1) (jig at/1) 00 25.10 34.83 23.20 4.95 0.32 09 25 8 23 34.78 23.13 4.92 0.31 46 25.24 34.73 23.12 4.94 0.26 91 23.46 34.96 23.79 5. 19 0.28 181 19.20 34.83 24.90 4.62 0a44 270 14.12 34.38 25.70 4. 13 0.94 359 09.52 34.11 26.36 3.50 1.78 533 06.34 34.16 26.87 1.20 2.82 717 05.07 34.36 2 7.18 0.97 3.11 901 04.38 34.45 27.33 1. 14 3.13 1088 03.80 3 4.51 27.44 1.27 3.11 1374 03.13 3 4.54 27.53 1.49 3.04 INTERPOLATED AND CALCULATED DEPTH T S 0- t A. D A D 1000 -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 25.10 34.33 23.20 0.000 1.837 10 25.23 34.73 23.13 0o047 1.840 20 25.23 34.78 2 3.13 0.095 1.792 30 25.24 34.78 23.12 0. 142 i.745 50 25.24 34o 23.12 0.23S 1.649 75 24.00 34.90 23.59 0.352 1.535 100 23.11 34.98 2 3.91 0.457 1.430 150 20.78 34. 2 -t.56 0.644 1.243 200 18.02 34.78 25.12 0.803 1.084 250 15.45 34.51 25.51 0.940 0.947 300 12.32 34.24 25.96 1.057 0.830 400 08.45 34.10 26.52 1.243 0.644 500 06.78 34.14 26.79 1.339 0.493 600 05.81 34.23 26.99 1.514 0.373 700 05.15 34.34 27.16 1.621 0.266 800 04.65 34.41 27.27 1.716 0.171 1000 04.20 34.47 27.37 1.387 0.000 STATION 1 M/V Hugh M. Smith: Cruise S, 20°48'N, 157°30'W, January 15, 1951. Messenger time: 0522 GCT. Weather: overcast (with breaks), no observation, to 20 ft. Wire angle: 35° Wind: 070u, 35 kt. Sea: 12 OBSERVED DEPTH T S a- t 02 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ng at/1) 00 24.50 34.23 2 3.42 4.9'! 10 24.51 34.83 23.42 4.33 26 24.52 34.38 23.42 4*35 51 24.52 34.88 23.42 4; 93 100 24.42 34.96 2 3.31 4-c92 200 17.41 34.74 25.24 4.22 302 11.93 34.22 26.02 4.05 397 09.76 34.13 26*50 3 « 0 0 493 3^.92 595 05.93 3 4.29 27.02 1.54 797 04.74 3 4.4-3 2 7 « 2 8 0.93 999 04.00 3 4.50 2 7 • 4 1 1.23 1197 03.61 3 4 » 5 6 7 7.50 1.39 INTERPOLATED AND CALCULAT1 ED DEPTH T s o- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 24.50 34* 8 f 25*42 0,000 1.854 10 24*51 3 4 , 8 3 2 3*42 0,04-5 1.809 20 24.51 3 4- e 8 R 2 3.42 0.090 1.764 30 24.52 3 4s 88 23.42 0. 134 1.720 50 24.52 34.8R 2 3.42 0.224 1.630 75 2 4.48 3 4 • 9 : 2 3.46 0.336 1.518 100 24.42 3 4*96 2 3,51 0,447 1.407 150 21.17 3 3 e 2 2 2 4,63 0e6^2 1.212 200 17,41 3 4,74 25,24 0,797 1.057 250 13.87 3^-s 39 2 5.76 0.925 0. 929 300 12*00 3 4,22 2 6,00 1.035 0. 819 400 OP. 67 34.13 26.51 1,219 0. 635 500 07,00 3^.20 26. PI 1.365 0. 439 6C0 05-93 3 4 • 2 9 2 7.02 1,483 0. 366 700 05*20 34. 37 27.17 1.593 0. 261 8 0 0 04. 7Q 34,41 27.26 1.687 0. 167 1000 03, 49 3 4,50 2 7.41 1,854 0. 000 STATION 2 M/V Hugh M. Smith: Cruise 8, 18°47'N, 158°01,W, January 15-16, 1951. Messenger titties first cast, 2330 GCT; second cast, 0000 GCT„ Weather: scattered clouds, no observation. Wind: 090 , 25 kt„ Sea: 12 to 20 ft„ Wire angle: first cast, 50°; second cast, no observation OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (Hg at/1) 3/b0 4.35 19 24.58 34.84 23.37 4.32 40 24.56 34.33 2 ■■ « 3 7 4.79 73 24a 49 34.33 2 3.3 9 4.33 143 24. OS 35.05 23.68 4.31 206 20.20 35.15 24.34 4.69 263 15.00 34.45 25. ?7 3.97 333i/ 11.23 34.21 2 6.14 3.61 301 1/2/ ' 10.85 34.19 26.19 3.83 394 437 1/2/ ' 08.72 34.35 26.67 1.13 527 521 2/2 ' 07.20 34.33 26.89 0.87 662 795 j_/ 05.56 34.41 27.16 0.7 8 795 05.94 34.41 27.12 INTERPOLATED AND CALCULAT] ED DEPTH T S -g at/1) 00 34#33 4.68 10 26»08 34.24 22.46 4.67 23 26,10 34* I 2 2.4 3 4.69 53 26.09 34^ 22.48 4.68 106 17,68 3 4,61 25.07 4,26 210 10.76 0.60 311 0c-.5 0 34.63 26.77 0.5 3 419 08.45 34.59 26.90 0,65 522 07*49 34.50 26.98 0.81 627 06.58 34.55 27.14 0.80 830 05.22 34.48 27.26 1.00 1027 04.36 3 4.52 27.40 1.37 1239 03.71 34.52 2 7.46 1.51 INTERPOLATED AND CALCULAT] ED DEPTH T s 0" t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) oO 26.10 34.33 2 2 e 5 2 0.000 1.575 10 26.08 3 4 s 2 4 2 2,46 Ce054 1*521 20 26.10 34.27 22.47 0.103 1.467 30 26.10 34.28 22. 1 0.161 1.414 50 26.09 34. 27 2 I . 4 8 0.269 i.306 75 22.50 3 4.23 2 3 • 9 7 6*386 1.139 100 18.12 3 4, E 24.96 0.474 1.101 150 12,48 34*55 .6.17 0.593 0.977 200 11.00 3 A , 6 .5 26.51 0.635 0. 39 0 250 10.12 34.65 26a 0.761 '0 « 8 1 4 300 09.63 34.64 2 6.75 0,831 Oe 744 400 08.66 34.60 2 6 . 3 C 0.962 0.613 500 07.71 34.52 2 6.9 6 1.086 0,489 600 06.82 34.54 27.10 1. 199 0,376 700 06.06 34.52 27.19 1.302 0.273 300 05.42 3 4.43 27.24 1.299 0.176 1000 04.45 34.52 2 7.33 1.573 OeQOC STATION 10 M/V Hugh M. Smith: Cruise 8, 09°00'N, 157°58'W, Janu- ary 19, 1951. Messenger time: first cast, 1930 GCT; second cast, 2015 GCT. Weather: continuous moderate rain, nimbo- stratus. Wind: 090°, 22 kt. Sea: 12-20 ft. Wire angle: first cast, 10°- A — -* in° OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ug at/1) 07 26.45 34.24 22.34 4.70 13 26.45 34.24 22.34 4.72 22 26.46 34.25 22.35 4.73 53 26.47 34.23 22.33 4*70 107 15.57 34.59 25.55 3c60 217 10.48 34*69 2^-64 0- 39 325 09.48 3 4 e 6 7 26*80 0:63 435 08.49 34.59 26«90 0-56 540 07.26 34.53 27.03 0i67 646 06*32 34.51 27- 15 0*73 897 04.94 34.58 27,37 0,9] 1103 04.06 34.52 2 7 e 4 2 Is 26 1305 03.52 34.61 27*54 ls50 INTERPOLATED AND CALCULATED DEPTH T S 1.061 150 11.55 3 4.64 26*4 3 0-5^9 0,948 200 10.68 34.68 26.60 0,678 0-869 250 10.28 3 4.69 26?^H 0-751 0e796 300 09.73 3 4.69 9 /'ft 0-820 0.727 400 08.80 34.62 26,87 0,950 0s597 500 07.73 34.55 26,98 1 . 0 t 2 0e475 600 06.71 3 4-5 1 2 7,09 1- 184 0.363 700 05.93 3 4 • 5 2 2 7.20 1,286 0.261 800 05-34 3 4*55 27.29 1*378 0.169 1000 04* 4ft 3 4,54 2 7.39 1.547 0.000 STATION 11 Cruise 8, 08°04'N, 157°58'W, Janu- M/V Hugh M. Smith ary 20, 1951. Messenger time: 0540 GCT. clouds, no observation. Wind: 090 , 23 kt. Wire angle: 10 Weather: broken Sea: 12-20 ft. OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ug at/1) 00 26.70 34.50 22.46 4.65 10 26.72 34.50 22.45 4.70 25 26.72 34.50 22.45 4.77 55 26.76 34.50 22.44 4.66 110 18.27 34.74 2 5.02 3. 12 215 10.64 34.66 26.60 0.86 320 09.44 34.67 26.31 0.98 429 08.66 34.61 26.39 1.20 533 07.63 34.58 27.02 0.73 633 06.59 34.54 27.13 1.00 843 05.40 34.53 27.28 0»79 1050 04.42 34.52 27.33 1.51 1256 03.63 34.57 27.50 1.48 INTERPOLATED AND CALCULAT] ED DEPTH T $ 0- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) UO 26. /U '34.50 22.46 0.000 1.581 10 26.72 34.50 2 2.45 0.054 1.527 20 26.72 34.50 22.45 0.103 1.473 30 26.72 34.50 22.45 0.162 1.419 50 26.75 34.50 22.44 0.270 1.311 75 23.40 34.95 23.30 0.390 1.191 100 18.79 34.77 24.92 0.480 1.101 150 13.45 34.53 25.96 0.610 0.971 200 11.00 34.63 26.51 0.702 0.879 250 10.19 34.69 26.70 0.776 0.805 300 09.62 34.68 26*79 0.845 0.736 400 08.83 34.62 26.86 0.975 0.606 500 08.00 34.59 26.97 1.098 0.483 600 06.94 34.55 27.09 1.211 0.370 700 06.18 34.61 27.24 1.311 0.270 800 05.64 34.53 27.25 1.404 0.177 1000 04.67 34.52 27.35 1.581 0.000 STATION 12 Cruise 8, 07°08'N, I57°58.'W, Janu- M/V Hugh M. Smith ary 20, 1951, Messenger time; 1413 GCT„ Weather: scattered clouds, cumulus, ft. Wire angle: 12° Wind: 080 , 20 kt. Sea: 5-8 OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ug at/1) 00 26,70 34.39 22.38 4.63 10 26.71 34.37 22.36 4.64 26 26.72 34.39 22.37 4.64 55 26.74 34.40 22.43 4.63 108 18.52 34.67 24.91 3.52 217 10.42 34.70 26.66 0.82 323 09.15 34.64 26.83 1.07 433 08.48 34.59 26.90 1.05 538 07.74 34.56 26.99 0.88 642 06.71 34.52 27.10 0.87 851 05.31 34.52 27.28 1.25 1065 04.32 34.53 27.40 1.43 1267 03.78 34.53 27.46 1.59 [INTERPOLATED AND CALCULATED DEPTH T s 0" t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.70 34.39 22.38 0.000 1.646 10 26.71 34.37 22.36 0.055 1.591 20 26.72 34.38 22.36 0.110 1.536 30 26.72 34.40 22.38 0. 165 1.481 50 26.73 34.47 22.43 0.274 1.372 75 25.40 34.94 23.19 0*401 1.245 100 24.00 35.06 23.71 0.513 1.133 150 13.31 34.50 25.96 0.671 0.975 200 10.83 34.68 26.58 0.761 0.885 250 10.02 34.69 26.73 0.834 0.812 300 09.40 34.66 26.81 0.901 0.745 400 08.68 34.61 26.88 1.029 0.617 500 08.07 34.57 26.95 1. 152 0.494 600 07.15 34.53 27.05 1.268 0.378 700 06.28 34.52 27.16 1.375 0.271 800 05.57 34.52 27.25 1.472 0.174 1000 04.56 34.53 27.37 1*646 OtOOO STATION 13 M/V Hugh M. Smith: Cruise 8, 05°59*N, 158°00'W, Janu- ary 21, 1951. Messenger time: 0020 GCT broken clouds, cumulus and altocumulus. Wind kt. Sea: 5-8 ft. Wire angle: 0° Weather: 100°, 18 OBSERVED DEPTH T S (T t oz PO4-P (m) (°C) (°/oo) (g/1) (ml/1) (ng at/1) 00 26.60 35.11 22.95 4.71 09 26.60 35.12 22.96 4.65 35 26.56 35.11 22.96 4.64 66 26.54 35.08 22.94 4.65 121 25.13 35.15 23.42 4. 13 232 10.31 34.72 26.70 0.54 333 08.92 34.65 26.88 1.53 460 08.13 34.57 26.93 1.33 553 07.38 34.60 27.07 0. 82 662 06.31 34.54 27.17 0.53 887 04.89 34.55 27.35 1.10 1097 04.12 3 4.59 27.47 1.44 1296 03.52 34.61 27.54 1.68 INTERPOLATED AND CALCULAT1 ED DEPTH T S o- t A D A D1000 -AD (m) <°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.60 35.11 22.95 0.000 1.652 10 26.60 35.12 22.96 0.049 1.603 20 26.58 35.12 22.96 0.098 1.554 30 26.57 35.11 22.96 0. 148 1.504 50 26.55 35.10 22.96 0.246 1.406 75 26.52 35.09 22.96 0.370 1.232 100 25.87 35.15 23.21 0.490 1.162 150 17,24 34.58 25.15 0.680 0.972 200 11.65 34.64 26.39 0.794 0.858 250 10.09 34.72 26.74 0.870 0.782 300 09.40 34.68 26.82 0.937 0.715 400 08.50 34.59 26.90 1.064 0.53S 500 07.86 34.57 26.93 1.185 0.467 600 06.90 34.58 27.12 1.295 0.357 700 06.00 34.54 27.21 1.396 0.256 800 05.30 34.55 27.31 1.437 0.165 1000 04.46 34.57 27.42 1.652 0.000 STATION 14 M/V Hugh M. Smith: Cruise 8, 05°00rN, J58O00'W, Janu- ary 21, 1951. Messenger time: 0845 GCT. scattered clouds, no observation. Sea: 8-12 ft. Wire angle: 15° Weather: Win. 130°, 25 kt. OBSERVED DEPTH T S (T t o2 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (ng at/1) on ?6*50 3 5.09 22.97 4.64 10 >ft,4ft 35.09 22.97 4.56 25 26t 41 3 5 s 1 ? 23*01 4.61 55 26*20 35a 10 23.07 4.58 112 26#11 3 5 • 1. 6 23*14 4.47 214 11.78 ■ J u » h 3 26-36 3 . J.7 319 09.20 34«^7 26*85 1*63 426 08.26 34eftl 26«95 Is 13 530 07.6? 3 ft • 5 q '•02 0s96 633 06.66 36.-56 2 7 s 1 4 0;80 836 05*14 3 4 « 5 3 27*31 1.00 1046 04« 24 34.5ft 27«43 1.40 1046 04-32 34*56 27.42 1252 03*52 34*56 2 7.50 1.78 INTERPOLATED AND CALCULAT] ED DEPTH T S 44 35a 19 23.06 4.77 43 26 .16 35. 17 23.13 4.78 80 25 .83 35. 14 23.21 4.77 147 25 »56 35. 15 23.30 4.74 226 10 .80 34. 78 26.66 2.45 M/V Hug 195 1. Mis sen STATION 57 o M. Smith: Cruise 8, 02 •er time: 1349 GCT. observation. Wind: 120°, 17 kt. 00'N, 162.57'W, February 10, Weather: scattered cloud's, no Sea: 8-12 ft. Wire angle: 45° DEPTH (m) T (°C) OBSERVED s (ml/1) (ug at/1) 04 28068 35.40 22.49 4„54 0„37 12 28.68 35.43 ll0 51 4054 0,36 25 28034 35.51 35.73A' 11, 69 4055 0.37 51 LOo t 3 £r&o 0 9— ■ 4.53 0.52 96 28. 12 35062 22 „ 84 4056 0.54 181 25.79 35.97 23^85 3041 Q„75 2671/ 16.21 35„71 26026 4.03 0.60 359 11„40 34.83 26.59 2.36 2.06 447 08.56 34067 26„95 2.99 l0ll 538 07.50 34059 27o05 2083 2„41 715 05.90 34.51 27.20 2.95 2.53 899 04o90 34D51 27G32 2o93 2.68 1089 04o19 34053 27041 2.87 2.76 I INTERPOLATED AND CALCULATED DEPTH 1 S a- t A D AD 1000 - AD M {°C\ «:°/ooi lgm/1) (dyn. m) {dyn„ m) 00 (28.70) (35.40) 22.49 0o000 1.997 10 28069 35042 Zl0 50 0o054 U943 20 28o40 35.49 22.65 0. 106 1.891 30 28.31 35. 52 22D69 0.158 1.839 50 28.25 35a 54 22c74 0.262 U735 75 28D 19 35o60 22.-80 0o390 1.607 100 28.12 35062 .84 0o517 lo480 150 27Q80 35.69 23^00 0o767 1.230 200 24. 10 36o05 24043 0.980 1.017 250 17a95 35.56 25a73 U129 0o868 300 14a20 35. 11 26„25 10234 0.763 400 09a 75 34072 26.80 1.395 0.602 500 07o90 34c62 27.01 1.519 0.478 600 06o82 34.56 27„ 12 1.629 0.368 700 06.00 34D52 270I9 1.730 0.267 800 05o40 34.51 27.26 1.824 0.173 1000 04.48 34.52 27„38 L997 0.000 1/ Anomalous values 0 2/ Point on T-S curve suggests bottle leaked on way up. There- fore all values at this level except temperature are probably in error„ STATION 81 07°01»S„ M/V Hugh M. Smiths Cruise 80 1„ 19510 Messenger time? 1304 GCTD clouds , cumulus and altocumulus 0 Winds Seas 3»5 ft0 Wire angles no observation 171 54'W,, March Weather 030°. ! broken 14 kt0 OBSERVED DEPTH T S o- t °2 PO4-P im) 1 <°c> 1 /&q) Cg/D Cml/1) Ctig at/1) 00 28o50 35038 22054 4059 0o38 10 28c48 35039 22055 4Q61 0o38 26 28o50 35D41 22„56 4o60 0o48 54 28018 i?o «5 8 22078 4054 0o49 107 28D04 35065 tiZ0 U7 4D57 0Q61 208 23027 36012 24Q72 3054 0o77 314 13o04 35o01 26a41 2047 1075 420 09o44 34o70 26Q83 2036 2025 523 07o79 34057 26099 2061 2o30 629 06o62 34052 27011 2087 2„28 834 05o 14 34o50 27a 29 2o70 2.53 1038 04o30 34a52 27„39 2a79 206l 1241 0.3.48 34Q55 27050 2085 2058 INTERPOLATED AND CALCULATED DEPTH T S 1,008 0,736 400 09,61 34.74 26e 33 1. 156 0.588 500 08,12 34.66 27,01 1.279 0.465 600 07,01 34,5? 27.11 1.389 0,355 700 06,09 34.56 27.21 1.490 0,254 800 05,37 34.56 27.30 1,521 0.163 1000 04,37 34.5S 27.43 1,744 0.000 STATION 89 M/V Hugh M. Smith; Cruise 8, DI°04'N, 17Z°00'.W, March 5, 1951. Messenger time: 0323 GCT. Weather: scattered clouds, cumulus and cirrus, ft. Wire angle: 60 Wind: 040 , 9 kt. Sea: 3-5 OBSERVED DEPTH T S a- t o2 po4- P (m) (c (C) <° 'oo) (g/D (ml/1) (|ig at A) 00 26. 70 35 • 24 23*02 4.81 0.62 09 26. 20 3 5 625 2 3.18 4.83 0.66 18 26< 10 3 3 25< i 95 35 s 26 23o26 4. SO 0.61 67 25. .88 112 25. ,77 35 .30 23*35 4.61 0.66 149 22. ,00 35 .24 24.42 4.81 0.67 191 14. ,00 3 4 .72 2 5.99 3. 14 1.41 238 12, ,34 34 667 26.29 3.00 1.62 302 11. ,07 34 .78 26.61 2.54 1.86 427 09. ,45 34 .70 2 6.83 1*56 2.31 544 07. ,65 34 .59 27-02 1.63 2.61 704 06. > 25 3 4 i,54 27,18 1.86 2.62 INTERPOLATED AND CALCULATI ED DEPTH T s (T t A D A DioOO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26, ?o 35.24 23.02 10 26.20 35.25 23.18 20 26.07 35.25 23.22 30 26.00 35.26 23.25 50 25.91 35.27 23.29 75 2 5.86 35.27 23.30 100 25.80 35.29 23.34 150 21.50 35.21 24.54 200 13.52 34069 26.07 250 12.02 34«69 26.36 300 11.10 34. IP 26.61 400 09.85 34.72 26.78 500 08.25 34o62 26.96 600 07.09 34.56 27.08 700 06.24 34.54 27.13 STATION 90 M/V Hugh M. Smith; Cruise 8, 01°34,N, 172°02'W> March 5, 1951. Messenger time: 1050 GCT. Weather: moderate intermittent rain, no observation. 3-5 ft. Wire angle: 36 Wind: 080 , 10 kt. Sea: OBSERVED DEPTH T S o- t 02 PO4-P (m) (°C) (°/oo) (g/D (ml/1) (fig at/1) 00 26o40 35.22 23.10 4. 36 0.67 12 26.34 35.22 23.11 4.86 0.68 28 26.22 35.21 23.14 4.84 0.61 59 26.13 35.25 23.20 4.73 0.70 118 26.00 35.22 23.22 4.63 0.76 226 11.97 34.80 26.46 2.95 1.71 329 10.38 34.75 26.71 1.77 2.27 448 09.66 34.70 26.80 1.60 2.41 561 07.76 34.59 27.01 2.08 2.53 685 06.60 34.53 27.12 1.66 2.81 934 04.59 34.53 27.37 2.06 2.90 1200 03.58 34.56 27.50 2.20 2.96 1469 02.96 34.61 27.60 2.40 2.90 INTERPOLATED AND CALCULAT] ED DEPTH T s o- t A D A D10OO -AD (m) (°C) (°/oo) (gm/D (dyn. m) (dyn. m) 06 26.40 35.22 23.10 0.000 1.814 10 26.38 35.22 23.10 0.043 1.766 20 26.29 35.22 23.13 0.096 1.718 30 26.22 35.21 23.14 0. 143 1.671 50 26.15 35.24 23.19 0.238 1.576 75 26.03 35.23 23.20 0.355 1.459 100 26.02 35.22 23.21 0.473 1.341 150 25.93 35.23 23.25 0.708 1.106 200 14.05 34.72 25.98 0.878 0.936 250 11.48 34.80 26.55 0.969 0.845 300 10.70 34.76 26.66 1.044 0.770 400 10.01 34.72 26.75 1.187 0.627 500 08.71 34.65 26.91 1.318 0.496 600 07.39 34.56 27.04 1.437 0.377 700 06.46 34.52 27.14 1.546 0.263 800 05.53 34.52 27.25 1.644 0.170 1000 04.31 34.54 27.41 1.814 0.000 STATION 91 M/V Hugh M 5, 1951 clouds, cumulus, 100°. 17 kt. Sea: Smith: Cruise 8, OZ^'N, 172U04'W, March Messenger time: 1858 GCT. Weather: broken stratocumulus and cumulonimbus. 5=8 ft. Wire angle: 52° Wind: OBSERVED DEPTH T S o- t o2 PO4-P (m) (°C) (°/oo) (g/1) (ml/1) (l^g at/1) 00 26.50 35.22 23.06 4.77 0.61 09 26e54 35.22 23.05 4.78 0.60 19 26.54 35.22 23.05 4.76 0.56 40 26.52 35.21 23.05 4.76 0.61 77 26.38 35.21 23.09 4.72 0.60 140 25.38 35.16 23.37 4e33 0.67 1921/ 12.03 35.19 26.75 4.64 0.76 251 10.64 34.74 26.65 2.51 1.97 311 10.26 34.74 26.72 1.69 2.23 382 09.7 0 34.70 26.79 1.57 2.44 541 08.09 34.61 26.98 1.91 2.50 736 06.00 34.56 27.23 1.46 2.82 957 04.53 34.53 27.38 1.95 2.88 INTERPOLATED AND CALCULAT] ED DEPTH T S o- t A D A D10OO- A D (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 26.50 35.22 23.06 0.000 1.756 10 26.53 35.21 23.05 0.043 1.708 20 26.53 35.21 23.05 0.097 1.659 30 26.52 35.21 23.05 0.145 1.611 50 26.45 35.21 23.07 0.242 1.514 75 26.38 35.21 23.09 0.362 1.394 100 26.24 35.21 23.14 0.432 1.274 150 24.21 35.13 23.70 0.708 1.048 200 11.70 34.75 26.47 0.355 0.901 250 10.66 34.75 26o66 0.932 0.824 300 10.36 34.74 26.71 1.003 0.753 400 09.52 34.68 26.80 1.141 0.615 500 08.51 34.63 26.93 1.269 0.487 600 07.45 34.59 27.05 1.386 0.370 700 06.38 34.57 27.19 1.492 0.264 800 05.50 34.55 27.28 1.586 0.170 1C00 (04.40) (34.53) 27.39 1.756 0.000 1/ Point on T-S curve suggests bottle leaked on way up. Therefore all values at this level except temperature are probably in error. STATION 92 M/V Hugh M. Smith: 1951, Cruise 03°57'N, 172°02'W, Messenger time: 0434 GCT cumulus, altocumulus and cirrus. Wind: 070 5-8 ft. Wire an.'le: 42° Weather: broken °. 16 kt March 6, clouds, OB SERVED (J t ! DEPTH T1 J. i c | o2 j PO4-P (m) I (°C) (°/oo) | (g/D i (ml/1) (|x{ at/1) 00 27.20 35,13 22.77 4.72 0.30 12 27.15 35*10 2 2 • 7 7 4.7^ 0.49 27 27.02 3^.10 22*81 4.68 0.48 56 26.83 33. 15 -. i I 4.66 0.58 109 2b. 3v 35.2 J. 2 3.03 4.68 0.68 205 j.6. 99 3 h o 71 25*31 2.84 1.29 3 0 3 09.21 34.65 26.iJ3 1.75 2.39 416 08.23 3 4.60 26.95 2.00 2.47 416 08.29 34.60 26.94 524 07.31 3 4.59 27.07 1.23 2.82 643 06a 3 / 34.55 27.17 1.23 3.00 882 0 4 • 8 6 34.56 2 7.3 7 1.85 2.94 1 127 0 3 0 c 9 3 4 .53 2 7.45 2.06 2.94 1407 03.12 3 4*58 27 .56 2.08 2.97 DEPTH (m) I N T E R P O LATED AND CALCULATED 00 10 20 30 5U 75 100 150 ZOO 250 300 400 500 600 700 800 1000 T (°C) 27.20 27.15 27.09 27.00 ^6.90 26.75 2b. 62 26.40 Id. 30 10.41 09.26 03.39 07.51 06.71 05.98 05.30 04.39 (°/oo) 3 5 • j. 3 3 3.10 35.10 35.10 35.13 35.17 35.19 33.21 34. dl 34*72 3 4.b5 34.60 34.59 34.57 34.36 34.56 34.54 ^ llx..*-? ?7«4f) 1 .1M, n.nnn STATION 103 M/V Hugh M. Smith: Cruise 8, 15 10, 1951 cumulus 00'N, 170U52'W, March Weather: dry haze, Messenger time: 0228 GCT Wind: 080°, 9 kt„ Sea: 3-5 ft. Wire angle: 12° OBSERVED DEPTH T S S curve suggests bottle leaked on way up0 Therefore all values at this level except temperature are Drobablv in error,. MID -PACIFIC OCEANOGRAPHY III TRANSEQUATORIAL WATERS AUGUST - OCTOBER 1951 By THOMAS S . AUSTIN PACIFIC OCEANIC FISHERY INVESTIGATIONS HONOLULU, T. H< CONTENTS Page Description of vessel, equipment, and procedures . . . 3 Some results of Hugh M. Smith cruise 11 3 J. G mpG i a.L\l± 6 9oac*««oeoaooosoo«o«o*«ooo««««««««*«* ** Sigma-t, salinity, inorganic phosphate, and oxygen . . , 5 V> ll r i G III. S «o«ooeoo«oooooeooooaaeoa«oooooooaaft«««**tt ® UlS CUSSlOn oeodasoaooa««osoaeoae*ftaa«ot(eaas«ao«ftao«a*««* ^ *■' Acknowledgements „ 0 . . . . „ . , « o » .... <, ........ . 12 J_jitCrcitU.r€r CltGQ Qoo0eoQOoaooooooaaQ9Q«e««Qoao«eo»««o«*«« * -^ X 3.DX6 1 oaoooaeeooaoaoaoeeoogea«ooo«aaoe«aaooo«o«o«aa«o* A -* List of figures . . ..... . ......... . . 17 Tabulated data MID-PACIFIC OCEANOGRAPHY III Introduction This is the third in a series of reports on oceanographic data collected by the Pacific Oceanic Fishery Investigations of the Fish and Wildlife Service„ The first (Cromwell 1951) presented the oceanographic data from Hugh Mc Smith cruise 2, the second (Cromwell 1954), the data from Hugh M0 Smith cruises 5 and 8, and this report will be concerned with Hugh Mc Smith cruise lle The apparently missing numbers in the series of cruises by the Smith have been as = signed to oceanographic cruises in the waters adjacent to the Hawaiian Islands or to fishery research cruises and will be the subject of other reports. These reports, descriptive in nature, are being issued in order that the oceanographic data may;, as quickly as is feasible, be made available to the other POFI investigations and to other organiza- tions interested in the equatorial mid-Pacific area. It is anticipated that, once the series is complete and the data from all the cruises can be studied together, a series of more comprehensive, analytical re- ports will follow0 The objectives of the equatorial oceanographic cruises have been to describe, in as great detail as possible, the major currents and the distribution of physical and chemical properties of the waters of the mid- Pacific, to determine the spatial and tem- poral variations in these phenomena, and finally to provide physical and chemical oceanographic data to which can be related the distri- bution and abundance of marine organisms, especially tuna, near the Equatorc Description of Vessel, Equipment, and Procedures The vessel, equipment, and procedures were described in some detail by Cromwell (1951, ppc 1-3),, The only significant change, which we will describe below, is in the procedure for draw- ing the salinity curves and constructing the cross sections as modi- fied from Montgomery (1954). Some Results of Hugh M„ Smith Cruise 11 Quoting from the cruise plan, the primary mission was "By means of (1) longline, (2) hydrogr aphic, and (31l plankton stations, investigate the abundance of yellowfin tuna with respect to certain physical, chemical, and biological features of equatorial waters away from the influence of emergent land masses, " The results of the longline fishing have been described by Murphy and Shomura (1953); the detailed plankton studies will be re- ported later0 The station pattern for the oceanographic phase of cruise 11 was planned to duplicate the positions of the fishing stations occupied along the southbound leg„ The positions of the fishing and oceanographic stations are shown on figure 1 (all figures are grouped at the end of the text)0 The data for the 22 stations appear in tabular form at the end of this reporta These data, along with those from the bathythermo- graph lowerings, are represented by vertical sections, figures 2, 3, and, 7 to 12. In the vertical sections, the position of each sample is indicated by a dot0 If for some reason (thermometer stuck, Nansen bottle leaked, bottle pretripped, etc„) it can be definitely ascertained that the value for the particular field is in error, it is discarded, the dot is not carried, and the deleted value is indicated by a dash in the tabulated data0 If a particular value is in doubt, but there is no ap- parent reason for its being in error, the dot is shown, the value is carried in the tabulated data and an appropriate footnote appended. Temperature; The temperature sections, figures 2 and 3, have been constructed from bathythermograph observations „ The data for figure 2 were collected during the southbound leg of the cruise (fishing) and those for figure 3 during the northbound leg (oceanogra- phy). The isotherms are plotted at 2-degree (F„) intervals; the maxi- mum depth of penetration is indicated by a dash„ During the southbound leg of the cruise, five BT's were taken at the positions of each fishing station, and one at each 10-mile interval between stations,, The data are plotted at 30-mile intervals in figure 2„ During the return section lowerings were made at 10- mile intervals between 5 S. and 12 N. and at 30=mile intervals from 12 No to 19 Nc All lowerings are plotted in figure 3. The most striking features of the two vertical tempera- ture sections, reading north to south in figures 2 and 3, are (1) the shallow, well developed thermocline in the region of the northern boundary of the Countercurrentj, and (2) the cooling of the surface water in the region of the equatorial divergence „ Typical temperature- depth traces, reconstructed from BT's taken in these regions, are shown on figure 4. 4 In comparing the two sections, the change in the vertical distribution of temperatures during the period between the two sec- tions is evident,, Of particular interest are the changes in slope of the transition layer in the Counter cur rent and the meridional shift in the center of the upwellingc In figure 5„ plots of the 60 , 70 , and 80° F. isotherms for each leg of the cruise, are given to show these changes. The wind data from both the southbound and northbound legs are summarized in figure 6„ The values from which the arrows were plotted are listed in Table I at the end of the reporto Wind speed and direction were recorded at each bathy- thermograph lowering,, These data were averaged for the total lower- ings between each degree of latitude; the speed and direction were averaged separately,, When there was a significant change in either speed or direction within 1 degree of latitude, i^c, 8 - 9 N. , south- bound section, less than the normal spacing of 1° of latitude was used. Resultant winds were not calculated, as the observational accuracy does not warrant this treatment and as the change in either speed or direction within the 60-mile limits was usually within the accuracy of measurement,. The data for each observation (number of observations shown at base of arrows) are available at the POFI, the Scripps Institution of Oceanography, and the U„ S. Navy Hydrographic Office „ During the southbound leg the winds were predominantly from the NE to about 8° N. , at which time they became light and variable and continued so to about 4° N„ From 4 N„ to the southern limit of the section the general direction shifted from southeasterly to easterlyc Along the northbound leg the arrows show predominantly NE to E„ winds 0 Sigma-t, salinity, inorganic phosphate, and oxygen; Montgomery (1954) points out the desirability of presenting the several variables, i0e„, temperature, salinity, phosphate, etc„ , in such a manner that the consistency among the several fields is readily vis- ible,, This can most easily be achieved by selecting a reference variable, and in this report sigma-t was the choice The data for sigma-t at an isopleth interval of 0o 2 g/1, as read from plots relating temperature, salinity, and sigma-t (Cromwell 1954, fig„ 1), were plotted for each station along with the observed values,, The isopleths were then drawn (fig„ 7)„ There was some smoothing, but with no violation of the observed points,, The points for the salinity (0D 2 °/oo isopleth interval) were taken from the T/S curves, and those for phosphate (0o 2 ugat/1 isopleth interval) and oxygen (0. 5 ml/1 isopleth interval) were read from the station curves and plotted,, In each case the observed values were also plotted,, Finally, the section plots for each of the three fields, -salinity, phosphate, and oxygen, were in turn placed over the sigma-t profile and isopleths drawn allowing them to run smoothly and as nearly parallel with those of the sigma-t surfaces as possible without violating the observed points (figs,, 8-10)„ Each of the fields was plotted only to a depth of 500 meters, thus permitting greater detail within the transition layer,, The principal feature of the sigma-t profile (fig„ 7), as with the previously described temperature sections, is the well developed gradient which lies at a minimum depth at the northern boundary of the Countercurrent (10 NQ), deepening to the south, with the maximum depth at the southern boundary of the Counter - current (5° N„)„ North of 10° N„ „ i„e. , in the North Equatorial Current, the distribution of the sigma-t surfaces with depth results in a less well defined density gradient,, At the Equator, the equato- rial divergence is reflected in a slight "doming" of the sigma-t surfaces. The salinity maximum at about 150 meters, 2° to 5 S. (fig„ 8), corresponds with that shown by Cromwell (1951, figse 12 and 13), Cromwell (1954, figsc 8, 18, and 30) and by Mao and Yoshida (1953, figc 15)„ In Cromwell's 1954 report, a tongue of high salinity (34.8 °/oo) is continuous from the northern to the southern limits of the sections; in the 1951 report, the bridge is continuous on the sec- tion along 172° W„ longitude but interrupted between about 15° N. and 9° N,, on along the 158th meridian,, Similarly, although the situation is less well defined, in figure 8 of the present report the tongue of high salinity is interrupted between 13° N„ and 8 N0 The deep tongue of low salinity water (34„ 2 °/oo) centered at about 300 m„ , 19 N„ , is rather characteristic of this area in equatorial Pacific. The same may be said for the low salinity waters at the surface between 5° N„ and 12° N„ , the zone of the Equatorial Countercurrent and the high rainfall beltc The values for surface phosphates along the section (figc 9) are somewhat irregular, but there is evident enrichment of the surface layers immediately south of the Equator (0o 6 to 0o 8 ugat/1), with a decrease to 0„ 2 |xg at/1 in the northern half» At about 8 - 9 N„ , the boundary zone between the North Equatorial Current and the Equa- torial Countercurrent, the cooler, nutrient-enriched waters are to be found slightly above 100 meters, but do not reach the surface As was the case with several previous sections in the mid-Pacific equatorial region (Sverdrup et al0 1946, Cromwell 195 U, there is direct evidence of upwelling immediately south of the Equator with the deeper, cooler, nutrient-rich waters replacing those at the surface„ Although a rigorous definition of upwelling is not possible at this time, mention should be made of the present apparent ambi- guity with respect to the term0 Sverdrup et al0 (1946, p0 501) de- scribe upwelling off the coast of California as the replacement of the light surface water by heavier sub-surface waters. At the Equator, the deeper waters are mixed into the surface layers from depths not exceeding ZOO to 300 meters,, Sverdrup and Fleming (1941, p„ 3.17) propose that the replacement of the surface waters should be dif- ferentiated from the increase (or decrease) in slope of the isotherms and isohalines resulting from current transport, and suggest that once a transport has reached a steady state the vertical displacement of the isopleths will stop and "the process cannot be called upwelling0 " This same line of reasoning is undoubtedly applicable when consider- ing the upwelling associated with the equatorial divergence and the in- crease or decrease in slope of the isotherms and isohalines associated with the mid-Pacific zonal circulation (see figD 5). We find both of the above-mentioned phenomena in the meridional section described in this reports Near the Equator there is upwelling associated with a wind-induced divergence,, The deeper waters mix with those at the surface;, resulting in a cooling of these surface waters and an increase in nutrients, such as phosphates, and conditions favorable to increased biological productivity ensue (King 1953, Murphy 1953, Sette MS)„ Throughout the region of the Countercurrent the second phenomenon, that of a vertical displacement of the isopleths associated with zonal flow, is to be found. The sigma-t surfaces (fig0 7) slope markedly, the 24 g/1 surface rising from 525 meters at 5° Nc to 50 meters at 9° NQ The 20 0 ug at/1 phosphate isopleth (fig„ 9) is near 300 meters at 4° N0 , sloping upward to 100 meters at 9 Nc To this situation Dietrich (1935, p. 57) assigns the term "dynamically caused upwelling0 " Even if there is occasional cooling and enrichment of surface waters at the boundary of a zonal current, such as the Equa- torial Countercurrent, it is believed that any use of the term upwelling is confusing,, Although the data on file at POF1 require considerable further study, there is little evidence that there is any mixing of the deeper waters with the surface waters at the northern edge of the Equatorial Countercurrent0 However, one must not overlook possi- bility that a shallow density gradient (fig0 7) coupled with strong winds might result in mixing of surface and deeper waters and produce a transient enrichment of surface waters „ Alsoc horizontal eddies (Cromwell 1951, Mao and Yoshida 1953) may effect a similar condi- tio^ Although deeper waters do not normally reach the surface in this region, the distribution of mass resulting from the zonal currents brings enriched waters into the subsurface euphotic zone. The bio- logical significance of this vertical displacement is not well understood and requires considerable further studyD The principal features of the vertical distribution of oxygen (fig0 10) are the relatively high values at or near the surface (40 0 - 40 5 ml/1) and the oxygen- minimum layer at intermediate depths,, An oxygen-rich layer is encountered at depths below 500 meters (see tabulated station data),, The subsurface layer of higher oxygen concentrations, 50 0 to 50 7 ml/1, centered at 100 meters between 19° N„ and 14° N0 8 may be associated with the intrusion of the northern subtropical water mass, while the inclination of the oxygen isolines in the same latitudes but below 100 meters suggests an association with an intermediate water mass. Comparison at the Equator of figures 7 and 10 suggests the mixing of upwelled waters of relatively low oxygen content with those at the surface. Currents; The dynamic topography is shown on figure 11, the geostrophic current velocities on figure 12. The actual results of the dynamic calculations are plotted in the former in order that the degree of smoothing of the isolines may be observed. The data for the stations at the Equator and at 1°N„ latitude were insufficient for calculations to the 1, 000-decibar surface (see footnote in tabulated data for stations 33 and 34)„ Because of the uncertainty of relative current computation for stations near the Equator, the isovels between 3-1/2 N0 and 3-1/2 S0 have not been included in figure 120 In figure 12, only the major features of the velocity dis- tribution as computed by the dynamic calculations are to be considered reliable,, Internal waves undoubtedly exert a strong, but quantitatively unknown influence. The most striking feature on both figures is the evidence of the Countercurrent flowing strongly to the east between 5 N„ and 10 No „ with the highest velocity of 80 cm, per second near the southern boundary,, This velocity may be somewhat low, as the plotted velocities represent an average between successive stations,. Another easterly flow, but of very small magnitude, is indicated between 17- 1/2° and 19-1/2° N„ The North Equatorial Current exists in a broad band between 10° and 17-1/2° N„ with velocities of 23 cm, /sec. or less,, 8 The Counter cur rent is strongest near its southern edge, with a maximum speed of. 80 cm„ /sec. between 55 and 75 meters. The 10 cm„ /sec. isovei reaches the 700-decibar surface immediately below the band of highest velocity, while at the northern edge the 7 cm0 /sec. level is between 25 and 50 meters with the bottom of the current (0-10 cm„ /sec. ) below the 700-decibar surface0 Consider- ably higher speeds are indicated down to the 700-decibar surface in the South Equatorial Current„ It is difficult to discuss the flow south of 5° Nc , the region of the South Equatorial Current;, with any degree of certainty,, The loss of data from the stations at the Equator and 1° N„ precludes drawing of the dynamic topography through this area. This is un- fortunate, as inspection of figure 12 shows a considerable difference in level across this region0 Figure 12 indicates a moderately strong westerly flow between the southern boundary of the Countercurrent and 3 Nr. and a westerly flow with velocities over 60 cm. /sec. between 3 S. and 5 S0 About all that can be said with certainty is that the South Equatorial Current was present, during the time of the cruise0 Supplementary information on the velocities of the cur- rents may be determined from the drift of the longline gear (Austin MS) used for sampling the fish population (gear described by Niska 1953) and from the drift of the vessel while on oceanographic stations. The former, in view of the relatively small effect of windage on the 8-mile length of the longline, yields a reliable estimate of both speed and direction of the current integrated over the depth of the lines (100 to 300 feet)„ The information from vessel drift is less reliable be- cause of the quantitatively unknown effect of wind and the fact that the determination of drift included running time between fixes0 Of particular interest on figure 2, upper panel, is the westerly set (North Equatorial Current) between 15° N„ and 9° N„ , the easterly set (Equatorial Countercurrent) between 8° - 9 N„ and 5° - 6 N„ , and the westerly set (South Equatorial Current) south of this latitude,, Attention is called to the easterly set (109 T„ ) at the Equator, which is significant when considering the submerged counter- current (the undercurrent) reported by Cromwell et al0 (1954)„ Also the three northernmost stations in the South Equatorial Current, particularly stations 9, 10, and 11 (fig„ 1), exhibit a northerly com- ponent, while those south of the Equator (25-27) show a southerly component (Cromwell 1953)0 When possible to calculate from available navigational data, the direction of drift while on oceanographic stations was determined and entered to the nearest cardinal point in the upper panel of figure 3„ No reliable data were available for 10 Nc nor south of 1° N. latitude0 The easterly drift of the Countercurrent is evident for stations at 6 and 7 N„ latitude,, The results for 8 N„ yielded a set of 270° Tos but if the effect of the wind could be accurately de- termined, it is believed the resultant current set would be to the east. At 5 N,, apparently at the boundary between the South Equatorial Current and the Equatorial Countercurrent, the net drift was zero. As pointed out by Cromwell (1951), information concern- ing the currents may be inferred from the wire angles during an oce- anographic cast0 The average wire angle for all stations in the North Equatorial Current was 23°, the wind speeds on station were 17-19 knots, blowing from the northeast,, In the Countercurrent, with winds from 14 - 19 knots from NE to ENE, the average wire angle was 12 . Considering the westerly moving North Equatorial Current and the easterly Countercurrent, this was as could be expected. Moving south from the southern edge of the Countercurrent (5 N0) into the South Equatorial Current, the wire angle increased from station to station from 20° at 5 N„ to 65 at the Equator, The wind, from E„ to ESE, was between 13 and 16 knots0 Considering that the minimum wire angles were found in the region of the maximum velocity of the South Equatorial Current (the northern edge) and that there was no appreciable change in wind between the northern edge of the South Equatorial Current and the Equator, it is possible that the large angles near the Equator were related to the undercurrent re- ported by Cromwell et al„ (1954), South of the Equator (2° S„ ) the angle fell to 10° (wind 08 knots) and increased to 35 at 5 S. (wind 18 knots)0 This latter angle is similar to that at stations with similar winds in the North Equatorial Current. Discussion Sette (MS), in a recent paper discussing the work of the Pacific Oceanic Fishery Investigations, states that the survey data from the east central equatorial Pacific "demonstrate that divergence and upwelling at the Equator enrich the surface waters with inorganic nutrient salts stimulating plankton production. Surface waters con- taining plankton drift northerly to an adjacent convergent zone. By inference this is believed to maintain a concentration of organisms of the trophic level above plankton, mainly small fish and squid, which in turn comprise food for yellowfin tuna, Neothunnus macropterus (Temminck and Schlegel)„ The system is generated and its structure largely governed by the winds,, " 10 Figure 13, in effect, summarizes the data from Hugh M, Smith cruise 11 and lends support to the above quotationc In this figure, surface values for temperature, salinity, oxygen, and phos- phate, the current speed, the zooplankton volumes, and the yellowfin catch have been plotted against latitude (vertical scale ). The first five fields plotted, namely, T„ S, O2, P04, and current speed repre- sent conditions as observed during the period of the cruisec The zoo- plankton, although sampled during the cruise, may be considered as the culmination of a series of events which had their origin during some previous period of upwelling, probably some distance to the east. The charge of nutrients thus brought to the surface was uti- lized by phytoplankton, and indirectly for the succeeding trophic levels, zooplankton, forage fish and squid, and the tuna„ Although we do not know the time required for the con- version of nutrients through the trophic levels to the tuna, the data presented in figure 13 suggest the integrated relationships among the oceanographic and the biological factors. The curves for the various fields (figa 13) nicely define the zones of interest„ Reading from north to south (top to bottom) the North Equatorial Current extends south to about 10° No, the Equatorial Countercurrent between 10 N„ and 5 N„ , and the South Equatorial Current from 5° N. to the southern limit of the section. The equatorial divergence is centered at 1 S. with the zone of convergence between this latitude and the southern boundary of the Countercurrent. Within the Countercurrent the salinity curve shows the typical increase toward the southern edge. The values for surface phosphates, associated with the center of upwelling, are somewhat atypical, with higher than usual values from the southern boundary of the section and lower values between the upwelling and the southern boundary of the Countercurrent. Several reasons for this could be advanced including mixing with surface waters of lower PO4 during the meridional transport (1° to 5 N„), variations in in- tensity of upwelling from cruise to cruise, and a reflection of the biological activity in the waters moving in from the east. The latitudinal variations in the abundance of zooplankton (fig. 13F) lend emphasis to the proposition of enrichment from the equatorial divergence. A more detailed discussion of this relation- ship between the plankton and the fish in this area is to be found in the report by Murphy and Shomura (1953) and in the report by Sette (MS) 11 Acknowledgements A report of this nature results from the combined efforts of many individuals,, Mr, Townsend Cromwell, as field party chief, was largely responsible for the successful completion of the program aboard the vessel„ Mary Lynne Godfrey, E. D„ Stroup, D„ Ching, and others processed the data. Tamotsu Nakata prepared the illus- trations. No sea-going program could be successful without the cooperation of the vessel personnel. Special thanks are due to the master and crew of the M/V Hugh M. Smith. The efforts of the above, and of many others, are grate- fully acknowledged. 12 LITERATURE CITED AUSTIN , T. S. MS Pacific equatorial undercurrent measured by longline drift. CROMWELL, TOWNSEND 1951 Mid-Pacific oceanography, January - March 1950. U.S. Fish and Wildlife Serv. , Spec. Sci. Rep.: Fish„ No. 54, 9 pp0 , 17 figs. , 53 tables. 1953 Circulation in a meridional plane in the central equatorial Pacific, Jour, of Mar„ Res., Vol. 12, No. 2, pp„ 196-213, 9 figs. 1954 Mid-Pacific oceanography II, transequatorial waters, June - August 1950, January - March 1951„ U.S. Fish and Wildlife Serv. , Spec. Sci. Rep.: Fish. No„ 131, 13 pp. , 32 figs. , 1 tableQ , R. B„ MONTGOMERY and E . D. STROUP 1954 Equatorial undercurrent in Pacific Ocean revealed by new methods. Science, Vol0 119, No. 3097, pp. 648-649, 2 figs. DIETRICH , G. 1935 Aufbau und Dynamik des sudlichen Agulhasstromgebietes. Veroff. Inst. Meeresk. Berlin, n. s. geogr. naturw. ser, , pt. 27, 79 pp. KING, JOSEPH E. and JOAN DEMOND 1953 Zooplankton abundance in the central Pacific. U.S. Fish and Wildlife Serv. , Fish. Bull. No. 82 (Vol. 54), pp. 111-144, 11 figs. , 18 tables. MAO, HAN-LEE and K. YOSHIDA 1953 Physical oceanography in the Marshall Islands area. Univ. of Calif „ , Scripps Inst, of Ocean., Ref. 53-27, April 15, 1953. 13 MONTGOMERY, R„ B„ 1954 Analysis of a Hugh JM_ . Smith oceanographic section from Honolulu southward across the Equator. Accepted for publication in the Jour, of Mar. Res., Vol. 13, No. 1. MURPHY, G. I. and RICHARDS. SHOMURA 1953 Longline fishing for deep-swimming tunas in the central Pacific, 1950-51. U.S. Fish and Wildlife Serv. , Spec. Sci. Rep.: Fish. No. 98, 47 pp. , 15 figs. , 20 tables. NISKA, EDWIN 1953 Construction details of tuna longline gear used by POFI. Comm, Fish. Rev. , Vol. 15, No. 6, pp. 1-6. SETTE, O. E. MS Nourishment of central Pacific stocks of tuna by the equa- torial circulation system. Paper for Eighth Pacific Science Congress, October 1953. SVERDRUP, H. U. and R„ H. FLEMING 1941 The waters off the coast of southern California, March to July, 1937. Bull, of the Scripps Inst, of Ocean. , Vol. 4, No. 10, pp. 261-378, 66 figs. , M. W. JOHNSON, and R. H. FLEMING 1946 The oceans, their physics, chemistry, and general biology (2nd ed. ) . x9 1087 pp, New York: Prentice-Hall, Inc„ 14 Table I (A) (Southbound) Average wind, direction and speed for observations recorded between latitudes listed in column 1 Position (along 150°W« longitude) Average direction T Average speed, knots Number of observations 19°07 18°06 17°00 16°04 15°09 14°15 13°06 12°10 11°13 10°08 9°H 8°17 7°57 7°08 6°00 5°04 4°31 4°00 3°10 2°11 •N •N nsr •N 'N 'N ■N 'N 'N ■ PALMYRA 1 8C»39 5° 5° ■ WASHINGTON 1 90*30 •FANNING 1 I0»37 1 1 I|0»36 I [L ft u5 ~HRISTMAS /Ms ° ° O 3 14 O O 20 21 13 ,. 00 ''0»35 22 IB 2393'' M" 1 0° •JARVI5 1 | 250 »32 260*31 •30 ■ MALDEN 1 27o| • 29 ?Sa| ■ST A tBi/CK I ■ FILIPPO REEF o LONGLINE STATIONS • HYDROGRAPHIC STATIONS IU° IE >5° 160° IE 5° 150° = 14 10° 5° Fig. 1 .-- Track chart, Hugh M. Smith cruise 1 1, August 20 through October 6, 1951. Open circles indicate positions of fishing stations (stations 1-28, August 24 - Sep- tember 25, 1951); solid dots, the positions of the hvdrographic stations (stations 28-50, September 26 - October 4, 1951.) a. Ul g cr. I h- i — i — r n — i — r / v j i i i i i i i_ K F ° N N ■*" 0 T r 5 w- S LI0 S go 40 30 go |0S.0oNr go jo 40 go 6o jo go go |Qo , ,o ,2o |3o |4o |5o |go |70 |go |go LATITUDE Fig. 2.-- Upper panel - direction and speed of longline drift at position of selected fishing stations (1-12, 23-28) shown on figure 1. Center panel - surface temper- atures recorded at position of bathythermograph lowerings during southbound sec- tion (fishing), Hugh M. Smith cruise 11. Lower panel - bathythermograph section, southbound section, Hugh M. Smith cruise 11. Isotherm interval 2.0 F. , depth of lowering indicated by small horizontal dash. The break in the section, between 1° and 2 N. latitudes, represents perid of cruises from 150 W. longitude to Christmas Island and return (stations 12-23, September 4-19, 1951) (fig. 1). UJ o < u. or => "i — i — i — i — i — r [ NO DATA J 1 I I I L_ ~\ — i — i — i — r . ., .. NO » DRIFT IN w— Ue J I I I I 85 80 75 0 100 200 300 400 X t- 0. UJ Q 500 600 700 800 900 5o 4o 30 2o |°s.o°-NI° 2° 3° 4° 5° 6° 7° 8° 9° 10° 11° 12° 13° 14° 15° 16° 17° 18° 19° LATITUDE Fig. 3.-- Upper panel - direction of drift of Hugh M. Smith during period on oceano- graphic stations. Center panel - surface temperatures as measured at each bathy- thermograph lowering. Lower panel - bathythermograph section, northbound sec- tion, Hugh M. Smith cruise 11 (stations 28-50, September 25 - October 4, 1951). Isotherm interval 2, 0° F. , depths of lowering indicated by small horizontal dash. Vertical dashed lines denote homogeneous water with the same temperature as that of the isotherm intersected by the dashed line. TEMPERATURE °F 50 60 70 80 0 200 400 600 800 80 80 80 80 80 80 80 1 1 1 ® SOUTH " EQUATORIAL / SOUTH OF \ \THE EQUATOR^ J 1 1 1 1 t UPWELUNG(r^°U™ , 0°29's EQUATORIAL j 1/ NORTH OF \/ / VTHE EOUATOR| ^^ 2° 10'N^X 1 1 s SOUTH EQUATORIAL 3° 00' N 1 1 1 ' EQUATORIAL COUNTERCURRENjy (MID REGIONU--^^^ ^^ 6 1 1 1] y^"^ y^ s^^^ / / EQUATORIAL / NORTH / r^ / s^ „__ — -^ /countercurrent/ EQUATORIAL/ l l i 1 " 1 1 1 ' (NORTHERN REGION)/ a°57'N / 1 1 1 1 I1 1 7° 00' N \s' 1 1 1 1 1 Fig. 4.-- Typical bathythermograph traces for various rec;ions -ropstd during Hugh M. Srrith cruise 11. \~ UJ UJ u_ I I- 0. UJ CI 100 200 300 400 400 500 600 600 700 800 900 i — r j _L J L FISHING SECTION (SOUTHBOUND) HYDROGRAPHIC SECTION (NORTHBOUND) i i I ~~i — I i I : 5o 40 30 2= |°S-0°NI° 2° 3° 4° 5° 6° 7° 8° 9° 10° II" 12° 13" 14° 15° 16° 17° 18° 19° LATITUDE Fig. 5.-- Comparison of the 60 , 70 , and 80 F. isotheims for southbound (solid line) and nonr r ound sections (broken line). NORTHBOUND SOUTHBOUND cc O 2 O 19° 18° 17° 16° 15° 14° 13° 12° I 1° 10° 9° 8° 7° 6° 5° 4° 3° 2° 1° 0° 1° 2° 3° 4° 5° OCT 4,1951 AUG 22,1951 \7 7 7 SEPT 26 N 000 315 W270- 225 * 045 090 E 135 180 S CO r- O z 0 10 ^20 14 \ % \ 5 ^10 SEPT 4,1951 TO XMAS ISLAND l0 SEPT 21,1951 9 SEPT 26,1951- Fig. 6.-- Wind and direction and speed, Hugh M. Smith cruise 11, northbound and southbound sections. Each arrow represents independent averages of speed and direction for total observations between arrows. The figure at the base of the arrow denotes the number of observations included in the averages. in UJ I 0. 100 200 - 300 400 500 5o 4o 30 2o |os.0o-N|o 2° 3° 4° 5° 6° 7° 8° 9° 10° 11° 12° 13° 14° 15° 16° 17° 18° 19' LATITUDE Fig. 7. -- Sigma-t, Hugh M. Smithcruise 1 1, stations 28-50, 5 S. - 19 N. , 150 W. longitude, September 26 through October 4, 1951. Sigma-t in grams per liter, isopleth interval 0.2 gm. /I. m ir uj 5 0- UJ Q 100 200 300 400 500 5° 4° 3° 2° l°S-0°-NI° 2° 3° 4° 5° 6° 7° 8° 9° 10° 11° 12° 13° 14° 15° 16° 17° 18° 19° LATITUDE Fig. 8. -- Salinity, Hugh M_. Smith cruise 11, stations 28-50, 5°S. - 19° N. , 150° W. longitude, September 26 through October 4, 1951. Salinity in parts per thousand, isopleth interval 0. 2 °/oo. "I t doe l in a: LU 100 200 300 400 - 500 8° 19° LATITUDE Fig. 9.-- Inorganic phosphate, Hugh M. Smith cruise 11, stations 28-50, 5° S. - 19° N. latitude, 1 50° W. longitude, September 26 through October 4, 1951. PO4 in microgram atoms per liter, isopleth intervals 0.2 (j.g at/1. en X I H a. 100 200 300 400 500 "t 1 1 i) 1 VI • • ' T5 J ;i\ :i — j — 1 1 j 1 : 1 3 1 1 1 — r • • • / * \ : a • • v • v • • • ^ • w • • 1 r 5° 4° 3° 2° l°S-0°-Nr 2° 3° 4° 5° 6° 7° 8" 9° 10° 11° 12° 13° 14° 15° 16° 17° 18° 19° LATITUDE Fig. 10.-- Dissolved oxygen, Hugh M. Smith cruise 11, stations 28-50, 5° S. - 19° N. latitude, 150° W. longitude, September 26 through October 4, 1951. Oxygen in milliliters per liter; isopleth intervals 0. 5 ml. /I. in a 1.9 - 1 1 ! 1 - 1 1 1 I 1 1 1 1 1 \ 1 1 1 1 I i i 1 1 8 1 7 ^ /■' 1.6 1.5 1 4 ^ 1.3 1.2 1 1 ^-20°"""""" __ X ' ^j^— -""" 1 0 1 1 1 1 q ^^^. _j^— - -" 8 . JOO— _ 7 . — — . — ■ — 6 , 400— - III -— . .5 4 , . — 700 — • - 2 1 II iii ! 1 1 1 1 5» 40 3° 2° |°s-0°-N 1° 5° 6" 7° 8° 9° 10° II" 12° 13° 14° 15° 16° 17° 18° 19° LATITUDE Fig. 11.-- Smooth profiles of the isobaric surfaces relative to the 1, 000-decibar surface, Hugh M. Smith cruise 11, stations 28-50, 5° S. - 19° N. latitude, 150° W. longitude, September 26 through October 4, 1951. (r 5 x 0- UJ o 0 100 200 300 400 500 600 700 I I 1 L I I I I I L 5° 4° 3° 2° l°S-0°-NI° 2° 3° 4° 5° 6° 7° 8° 9° 10° 11° 12° 13° 14° 15° 16° 17° 18° 19° LATITUDE Fig. 12.-- Vertical section, geostrophic currents, Hugh M. Smith cruise 11, based on the smooth profiles (fig. 11). Current speed indicated in centimeters per second. * o z o Ix. X U m §8 kJ I H < .Q O X. u 0 O n Z H g 5 o • ? o < o -^ Q. >* 0) O o ■ O " "2 o x E 2 o 0 s XI n ■0 c d c ri Ph X a. rt *j Ml O B 3 X! o 0 n X B 0 3 n r. > • aaniiivi 3 _ — c IT) Remarks- about the oceanography data Weather was recorded according to the ww code as it appears in The US W B- Circular M, Instructions to Ma-r ne Meteorological Observers, Wind velocity was measured using an anemometer located 30 m. above the sea surface. In the tabulated data, the horizontal line(s) between depths separates the two or more casts necessary during the particular station. Whenever there is no doubt concerning data being in error (Nansen bottle pretnp, bottle leakage, etc. ), these data are not carried in the tabulations and a footnote is appended If values are doubtful, but there is no positive evidence of an error, the data are carried with appropriate footnotes. STATION 28 M/V Hugh Mo Smith: Cruise 11, 04°57'S, 150°04'W, September 25, 1951. Messenger time: 1818 OCT. Weather; 02, cloud coverage 4. Wind; 110°, 18 kt. Sea: 1-3 ft„ Wire angle: 35°. Depth of water: no data OBSERVED DEPTH 1 T S a t 02 PO4-P (m) ! (°C) (°/oo) (g/D (ml A) (|j.g at/1) CO 27.10 35.55 23.. 13 4. 55 09 27. 10 35.57 23. 14 4.56 21 27. 10 35.59 23. 15 4. 56 44 27c 10 35.57 23. 14 4.50 86 27. 11 35.59 23. 15 4.56 164 21.93 35.60 24.71 4. 56 237 13.37 35.02 26.35 1.87 312 10.92 1/ 1 / 386 09.70 34.71 26.79 1.75 459 08.84 34.64 26.88 1.30 597 07.26 34.61 27. 10 1.93 749 06.03 34.53 27.20 2. 16 921 05. 12 34.54 27.32 2.48 | INTERPOLATED AND CALCULATED i DEPTH T S 0- t AD AD 1000- AD (m) f°C) fc/oo) (gm/1) (dyn. m) (dyn. m) 00 27. 10 35.55 23. 13 0.000 1.799 10 27. 10 35.57 23. 14 0.048 1.751 20 27. 10 35.59 23. 15 0.095 1.704 30 27. 10 35.59 23. 15 0. 142 1.657 50 27. 10 35. 57 23. 14 0.237 1.562 75 27„ 10 35.58 23. 14 0.357 1.442 100 27.08 35.59 23. 16 0.476 1.323 150 23.32 35.61 24.32 0.687 1. 112 200 18.83 35.48 25.45 0.842 0.957 250 12.74 34.98 26.45 0.945 0.854 300 11. 17 34.83 26.63 1.023 0.776 400 09.53 34.70 26.82 1. 151 0.648 500 08.30 34.63 26.96 1.278 0.521 600 07.20 34.61 27. 11 1.391 0.408 700 06.38 34.55 27. 17 1.494 0.305 800 05.74 34.54 27.24 1.592 0.207 1000 04.87 (34.54) 27. 35 1.799 0.000 1/ Unreasonable chemical values suggest Nansen bottle leakage. STATION 29 04°00,S, 150°00'W, M/V Hugh M. Smith: Cruise 11, September 26, 1951. Messenger time: 0916 GCT. Weather: 02, cloud coverage 0. "Wine: 090 , 8 kt. Sea: no data. 02, cloud coverage 0 < 1 ft. Wire angle: 25 . Depth of water OBSERVED DEPTH T S 5i 2 7*16 1.55 353 05. 25 34. »54 27.30 1*96 1066 04. 11 1/ 1/ 126A 03. 66 34« .55 27*43 2. 32 INTERPOLATED AND CALCULATED DEPTH T s 0- t A D A D10OO -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 27*30 35*60 2 3 e 1 0 C#000 1.687 10 27.25 35.61 23*12 0.048 1.639 20 27.20 3 5.60 2 3.13 0.095 1.592 30 27.17 35.59 23.13 0.143 1.544 50 27.16 35.58 2 3 c 1 3 0.23S 1 .449 75 27.12 3 5.59 23.14 0.358 1.329 100 26.93 35.61 2 3.22 0.476 1.211 150 20.25 35.55 2 5 c 1 3 0*675 1.012 200 11.96 34.95 26.58 0.786 0.901 250 11.42 34o37 26.61 0*361 0.626 300 11.10 34.32 26*63 0.935 0.752 400 10.28 34.79 26.76 1.079 0*608 500 02.61 34.68 26.95 1.209 0.473 600 07.16 34.60 27.10 1*322 0.365 700 06.29 34.56 27.19 1.424 0.263 800 05.60 34.54 27.26 1.519 0.168 1000 04.5 0 34.62 2 7*45 1*687 0*000 _1/ Unreasonable chemical values suggest Nansen bottle leakage, Z_l Phosphate sample useless due to addition of wrong reagents. M/V Kuq STATION 31 M. Smith: Cruise 11. 02°00'S, 150°0Z,W, September 27, 1951. Weather: 02 Messenger time: 0241 GCT. cloud coverage 2. Wind: 120 , 9 kt. Sea: < 1 ft. Wire angle: 08 . Depth of water: no data OBSERVED DEPTH T S 24 0.34 0.39 0.46 1.07 1.11 [NTERPOLATED AND CALCULAT] ED DEPTH T S cr t A D A Di000 -AD (m) (°C) (°/oo) (gm/1) (dyn. m) (dyn. m) 00 27.20 3b. 21 '1 • ' H~>T 10 27.03 35.17 2 2 a ~: ft 20 26.82 35.17 2 2 • 9 2 30 26.56 35.L9 2 3.02 50 26»17 35.20 2 3 • 1 5 75 25.70 35.20 23.30 100 25*20 35.20 23.45 150 15.87 3 5.26 ^5,28 200 13,70 35.0.4 26.30 1/ Values below 233 meters discarded, depths uncertain. Suspect pretripping; 2/ Suspected wrong break. STATION 34 M/V Hugh. M. Smith; Cruise 11, 01°Q2'N, 150°01'W, September 28, 1951. Messenger time: first cast, 0744 GCT; second cast, 0811 GCT; third cast, 0845 GCTo Weather: 02, cloud coverage not recorded. Wind: 090°, 16 kt. Sea: 1-3 ft. Wire angle: first o cast, 57 ; second cast of water: no data , 57°; third cast, 64 . Depth OBSERVED DEPTH (m) T (°C) S (°/oo) & 4.43 0.45 74 27.30 34.95 2 2.61 4.47 0.48 141 24.97 35.12 23.46 4.01 0.69 202 12.34 3 4.35 26.43 1.54 1.92 267 11.34 34.35 26.52 1.53 1.98 331 11.13 34.79 26.61 1.13 2.24 395 10.42 34.73 26.69 1.83 2.07 522 03.44 3 4.63 2 6.93 1.04 2.5 3 653 06.74 1/ 1/ 1/ 817 05.32 34.70 27.42 1.76 2.23 INTERPOLATED AND CALCULAT] ED DEPTH T S