properties at standard depths by means of a 

 subroutine furnished by the University of Wash- 

 ington Oceanography Department and based on 

 the interpolation method outlined by Rattray 

 (1962). 



In the region of study, a sharp thermocline 

 generally separates a surface mixed layer from 

 the subsurface waters. Only infrequently do 

 Nansen casts adequately define this configura- 

 tion, with the result that the interpolation pro- 

 gram provides inaccurate values for tempera- 

 ture. BT data were used to correct the tem- 

 perature-depth curve in the thermocline and 

 the isothermal layer. When necessary, a value 

 of temperature was chosen from, the corrected 

 curve at standard depths in the mixed layer and 

 upper thermocline and, with the corresponding 

 salinity value from the T-S curve, was used 

 with the Nansen cast data in the interpolation 

 program. The resulting interpolated values 

 were much nearer the actual oceanographic 

 situation as implied by the BT trace. 



To estimate the validity of values for the 

 surface distribution charts, the surface bucket 

 values of temperature and salinity were com- 

 pared, for each cruise, with values from the 

 surface Nansen bottles. For temperature, var- 

 iation was fairly random so that the mean of 

 the difference between the two values was well 

 within the accuracy of the surface bucket ther- 

 mometer. The root mean square value com- 

 puted from the above differences was less than 

 0.2° C. The bucket salinity values, on the 

 other hand, were consistently larger than the 

 Nansen bottle values, most probably owing to 

 salt contamination at the time of sampling. The 

 mean of the differences was about 0.03 °/oo 

 and the root mean square value was within 

 0.07 °/oo for each cruise. 



PRESENTATION OF DATA 



For each of the three cruises the original as 

 well as derived data and section plots for the 

 properties have been included. 



Tables 1, 2, and 3 contain the oceanographic 

 station data for cruises 4, 5, and 6, respec- 

 tively. In addition to the position, date, and 

 time at each station, weather and sea conditions 

 in standard notation have been included in the 

 heading of each station. The first five columns 

 of each station listing show the observed depth, 

 temperature, salinity, oxygen, and phosphate,£/ 

 respectively; the next two columns contain cal- 

 culated sigma-t and specific volume anomaly 



for the observed data. The next three columns 

 present the interpolated values of temperature 

 and salinity at standard depths and the last 

 three columns contain sigma-t and the specific 

 volume anomaly calculated from the interpo- 

 lated data and the anomaly of dynamic height 

 summed from the surface. The error terms, 

 defined by the Rattray interpolation technique, 

 that exceeded 0.10 for temperature and 0.05 for 

 salinity have been noted below the tabulation 

 for each station. Interpolated and extrapolated 

 values as well as irregularities in the original 

 data are noted in these tables. 



Temperature distribution sections along long. 

 148° W., 151° W., 154° W., and 157° W. based 

 on the 270-m. BT's are included; so are the 

 shorter zonal sections between stations 7 and 

 7A, 25 and 26, and 37 and 40. In addition, sur- 

 face temperature and salinities are presented 

 with each section. All the sections were plotted 

 automatically by the model 566 Calcomp plotter 

 with a program designed at HL. These seven 

 BT sections are shown in figures 2 through 7 

 for cruise 4, figures 8 through 13 for cruise 5, 

 and figures 14 through 19 for cruise 6. 



The surface temperature distributions, based 

 on bucket temperature at each BT cast, are 

 shown in figures 20, 21, and 22 for cruises 4, 

 5, and 6, respectively. 



The surface salinity distributions, based on 

 bucket salinity samples at each BT cast, are 

 shown in figures 23, 24, and 25 for cruises 4, 

 5, and 6, respectively. 



The dynamic topography, relative to 1,200 m. 

 for cruises 4, 5, and 6, is shown in figures 26, 

 27, and 28, respectively. 



ACKNOWLEDGMENTS 



The data for these cruises were processed 

 by HL personnel under the direction of Mary 

 Lynne Godfrey. Betty Ann L. Keala did the 

 computer programing. 



3/ 



— Oxygen and phosphate data are available only 



for cruise 6. The columns in the tables for 



cruises 4 and 5 bear the oxygen and phosphate 



headings only to have a uniform format for this 



series of reports. 



