HUGH M. SMITH CRUISE 20 



Summary Cruise Report 



Cruise 20 of the Hugh M. Smith extended from February 25, 1953, 

 to April 4, 1953. The area covered was essentially the same as that of 

 previous survey cruises in the offshore waters of the Hawaiian Islands, 

 except for the extension of the western limit to 16 1 30'W. and the south- 

 ern limit to 17 20'S. In addition there were two exploratory lines of 

 stations up to 29°N. along 155 W. and 158 W. 



Figure II shows the position of the 69 hydrographic stations where 

 water sannples were collected to a depth of 1,000 m. Oblique zooplankton 

 tows were made to a depth of 200 m. on each station except station 34, 

 where a surface tow was made. Other observations were as follows; bathy- 

 thermograph lowerings on each station and one between stations; four 

 daily synoptic weather observations, which were passed on to the U. S. 

 Weather Bureau; and GEK observations at each bathythermograph posi- 

 tion. These latter were made with unfloated electrodes except on 3 3 

 occasions where duplicate GEK runs were made with floated electrodes. 



The hydrographic survey part of the cruise began on March 9, 1953. 

 Station 12 was occupied March 15 so that the region south of 24 N. , the 

 main survey region, was covered in 19 days. 



Meteorological Conditions 



No greatly varying weather conditions were encountered throughout 



the cruise. North of latitude 24 N. the air temperature decreased from 



71 F. to 66.5 F. at stations 6 and 7. The average temperature over the 



whole of the main cruise area was 73 F. Within this area the average air 



o 

 temperature encountered north of the island chain was 72 F. , with extremes 



of 71 F. and 75 F. , and to the south it was 74 F. with extremes of 73 F. 



and 77°F. 



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Winds were predominantly from 080 T. and ranged from 40 to 



130 T. On only ten stations did they have a southerly component. Wind 



speeds were predominantly within a range of 15 to 22 knots. On only six 



stations was it greater than 22 knots, with a maximum of 30 knots. 



Calmer weather (winds less than 15 knots) prevailed during the latter 



part of the cruise, between stations 52 and 61. 



Light rain was encountered on five stations which were scattered 

 throughout the cruise. 



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