120° E, 130° 140° 150° 160° 170° 180° 170° 160° 150° I40f |30^ 120^ 1 10° W. 100 ° 



,, METEOROLOGICAL 

 U STUDY REGION 



TWZO REGION 



120° E 130° 140° 150° 160° 170° I80f 170° 160° 150° 140^ I30f 120° 110° W .100° 



Figure 1. — The regions of oceanographic and meteorological observations for the Trade Wind Zone 



Oceanography Pilot Study. 



SOURCES OF DATA 



About 80,000 sets of meteorological obser- 

 vations were used in the preparation of this 

 report. Their principal source was the surface 

 marine observations Card Deck No. 128 of the 

 National Weather Records Center. To those 



data were added the meteorological observa- 

 tions recorded on board the BCF (Bureau of 

 Commercial Fisheries) research vessels Town - 

 send Cromwell and Charles H. Gilbert that were 

 not already a part of the surface marine deck. 



Meteorological data for the central North Pa- 

 cific south of Hawaii are scarce. It is therefore 

 valuable to add to the surface marine observa- 

 tions those made on Johnston Island (lat. 16°45' 

 N., long. 169°30' W.) and on Christmas Island 

 (lat. 1°51' N., long. 157°23' W.). Since both is- 

 lands are atolls, the early morning meteorolog- 

 ical conditions would approximate those over 

 the adjacent ocean. Sea-level observations for 

 Johnston Island were obtained from the National 

 Weather Records Center, Card Deck No. 144. 

 At Christmas Island, meteorological observa- 

 tions were made three times daily for BCF. 

 The IBOOG.m.t. synoptic meteorological obser- 



vations from the two islands (0800 local time, 

 Christmas Island, and 0700 local time, Johnston 

 Island) have been combined with the surface 

 marine data. 



PROCESSING OF DATA 



The meteorological data were initially sorted 

 chronologically by day and by 1° square units of 

 area. When more than one set of observations 

 occurred in a 1° square per day, the meteoro- 

 logical properties, including the wind speeds 

 and the zonal and meridional components of the 

 wind velocity, were averaged. Consequently, 

 only one set of meteorological observations can 

 occur per day in any 1° square. 



Quality control over the large number of data 

 proved to be a major task. I inspected an initial 

 listing of the data and eliminated obviously er- 

 roneous values, determined by comparison with 

 values on record for the same geographic re- 

 gion and within a few days. 



At the time of the initial sorting, I also com- 

 puted derived properties and heat exchange 

 processes. Thus the magnetic tape, which is 

 kept on file to permit a more detailed analysis 



