several summaries are compiled depending on their 

 intended use. For a more detailed description of how 

 the observations are received and processed, see 

 Johnson, Flittner, and Cline (1965). Although specific 

 program details have been changed, the present pro- 

 cessing methods are essentially the same as those de- 

 scribed in that publication. 



Because the data are compiled from merchant and 

 fishing vessel marine weather reports, the spatial and 

 temporal distributions of observations over the ocean 

 are irregular. Observations are most numerous in the 

 major shipping lanes from San Francisco to Hawaii, 

 from San Francisco to Japan, from Panama to San 

 Diego, Los Angeles, and San Francisco, and from 

 Seattle to Japan. Shipping lanes of secondary impor- 

 tance are from San Diego to Hawaii and Panama to 

 Hawaii. 



The average number of marine synoptic observa- 

 tions taken per month over the period 1961-71 by 5° 

 quadrangles for the winter and summer seasons is 

 shown in Figures la and lb, respectively. The density 

 of observations is shown in class intervals of 50 as 

 indicated on the charts. Compilations made for the 



spring and fall seasons show the density distribution 

 for spring similar to that of winter and the density 

 distribution for fall similar to that of summer. 



In all seasons, most observations are taken along 

 the shipping lane between San Francisco and Hawaii 

 and the coastal route from Panama to U.S. west coast 

 ports. The least number of observations are taken 

 northwest of Hawaii and between lat. 25° and 30°N 

 during the summer season. The main difference be- 

 tween the winter and summer distributions is the 

 southward shift of greatest observation density west of 

 long. 145°W from the great circle route to Japan during 

 summer to between lat. 30° and 35°N during winter. 



INITIAL DATA PROCESSING AND CHART 

 PREPARATION 



Marine Environmental Variable and Heat 

 Exchange Summaries 



An intermediate step between reception of the 

 synoptic marine data and preparation of the charts 

 presented in this report is the compilation by 5° quad- 

 rangles of monthly mean marine synoptic variables 



I80®W 175 W 



I70W 165 W 160W 155 W I50W 145 W 140 W r35 W I30W 125 W I20W 



Figure la. — Average number of observations per month during winter seasons for 1961-71. 



9 



