At all stations where 13-bottle 

 casts were used the spacing of the bottles 

 (usually 6) above 300 m. was determined by 

 the characteristic of the bathythermograph 

 (BT) trace. At the 1,200-m. stations the 

 remaining seven bottles were placed at the 

 standard depths of 300, 400, 500, 600, 800, 

 1,000, and 1,200 m. At the stations where 

 13-bottle casts were made to depths of 

 1,400-1,500 meters the intervals between 

 the seven deepest bottles were slightly in- 

 creased. At two-cast stations the first cast 

 was to 600 meters with 13 bottles, the spacing 

 dependent upon the BT trace. The second 

 had 9 bottles placed at approximately 800, 

 1,000, 1,200, 1,400, 1,600, 1,800, 2,000, 

 2, 250, and 2, 500 meters. As the depth of 

 these casts was decreased because of the 

 loss of wire, the intervals were decreased. 



b. Salinity samples were drawn 

 from each Nansen bottle and returned to the 

 POFI laboratory for analysis. To preclude 

 evaporation, each sample was stoppered with 

 a paraffin -impregnated cork in addition to 

 the screw cap. Additional samples were 



drawn at several stations at the northern end 



o , o . 



of the 180 and 165 W. transects and ana- 

 lyzed aboard ship to make certain that the 

 sections extended into the Subarctic water. 

 Additional surface salinity samples were 

 taken at all off station BT's (last column, 

 table 2). 



c. Dissolved oxygen analyses using 

 the Winkler method were made aboard ship 

 on samples from each depth and from all 

 the oceanographic stations. 



d. Inorganic phosphate analyses were 

 also made aboard ship. Subsequent analyses 

 of the resulting data showed that the Automatic 

 Servo-Operated Photometer was malfunctional 

 and the data are not useable. 



e. Bathythermograph lowerings were 

 made twice at each station and at 30-mile in- 

 tervals between stations. On station the first 

 lowering was made on arrival to determine 

 the vertical distribution of temperature which 

 was then used as a guide in spacing the Nansen 

 bottles. The second was made as the cast was 

 being tripped in order to obtain a continuous 

 record of the vertical temperature for use with 

 the reversing thermometer values in construct- 

 ing the temperature-depth curves. The bathy- 

 thermograph log sheets (Log Sheet "B") are 

 summarized in table 2, and figures 2 to 6 are 

 plots from the corrected BT slides. 



f. The thermal element of the ship's 

 recording thermograph failed after 8 days of 

 operation, so a continuous record of the sur- 

 face temperature was obtained only on the run 

 from Pearl Harbor to Midway Island. In the 

 northern part of the area, north of 40 N. , 

 where sharp changes of temperature were en- 

 countered, hourly bucket temperatures were 

 taken in addition to the BT temperatures at 

 30-mile intervals. 



g. No GEK current measurements 

 were taken because of instrument failure. 



h. Secchi disk observations of water 

 transparency and color measurements (Forel 

 scale) were made at 39 stations. The results 

 are listed in table 1. 



i. Bottom profiles were obtained 

 over about 25 percent of the track by means 

 of the EDO echo sounder. The EDO worked 

 only intermittently on the run to Midway, 

 where it was adjusted by technicians from the 

 U. S. Naval Air Station. It was then operated 

 continuously to about station 44 where it failed 

 completely. The resulting data have been for- 

 warded to the U. S. N. Hydrographic Office. 



2. Plankton 



a. Thirty-minute oblique hauls to a 

 depth of 140 meters, employing a 1-meter net 

 of 30XXX grit gauze, were made at 78 of the 

 oceanographic stations. All nets were equip- 

 ped with Atlas flowmeters, which were cali- 

 brated before and after the cruise. 



The cruise plan also called for 

 three -net oblique plankton hauls with basically 

 the same type of nets as those used in the 140 

 m. hauls, to sample plankton from three 

 levels: near the surface, the region of the 

 thermocline (40-95 m. ), and below the thermo- 

 cline (95-440 m. ). Three-net hauls were tried 

 without success at the five daylight stations on 

 the run to Midway and then abandoned. After 

 Midway, the 140 m. oblique hauls were then 

 supplemented with shallow oblique hauls, the 

 depths of which were adjusted so that sampling 

 was completely above the thermocline, or to 

 40 m. if there was no homogeneous surface 

 layer. Fifteen samples from the shallow hauls 

 made on the 172 30'W. transect were frozen 

 for later analysis of fat, glycogen, and protein 

 content. 



