and heat exchange values that are computed from the 

 variables. The initial output format consists of a deck 

 of computer cards which are sorted and reprocessed in 

 order to display the values in a geographic format. 

 Each of the variables and heat exchange terms (de- 

 scribed below) is printed in this format after three 

 summaries have been made: 1) long-term mean 

 monthly values computed over the years 1961-71; 2) 

 monthly mean values computed for a given month and 

 year; and 3) deviations of a value for a given month 

 and year from the long-term monthly mean, i.e., anom- 

 aly values. 



Heat Exchange Computations 



For a given area and time period, the equation for 

 the energy exchange at the air-sea interface is Q[ = 

 Qio ~ Qr + Oh + Qc + Qs- Energy exchange calcula- 

 tions presented here do not take into account changes 

 in heat brought about by advection. 



Qi,). the incoming solar radiation corrected for 

 cloud cover (cal/cm-/day), is determined from the fol- 

 lowing equation proposed by Berliand (1960): 



Qio= (Berliand table) {] - aC - hC-) 



where C= cloudiness in tenths; 

 h= 0.38; and 

 a= a function of latitude. 



Berliand's table, which lists values by month and 

 latitude of incoming solar radiation with a clear sky, 

 and values of "a" are given in .Fohnson et al. (1965). 

 Of the incoming radiation corrected for the screen- 

 ing effects of cloud cover, some is reflected at the sea 

 surface. The amount retlected depends on the latitude 

 and time of year and is computed from 



Qr = C^v, • '■ 



where /• = percentage of radiation reflected given in a 

 table by Budyko (1956). The percentage varies from 

 about 6% in low latitudes to more than 209? in high 

 latitudes in winter. In preparing the charts, Qio and Q,. 

 were combined in a single term Qj, the incoming radia- 

 tion corrected for cloud cover and reflection, defined 



by Qi = Qio - Qr. 



Effective back radiation. Qj, (cal/cm7day), is the 

 difference between long-wave radiation from the sea 

 surface and long-wave radiation from the atmosphere. 

 The following semiempirical equation proposed by 



AVERAGE NUMBER OF 



OBSERVATIONS PER MONTH 



DURING SUMMER SEASONS 



1961 -1971 



< 50 

 50-99 

 100-149 

 > 150 



l»0«W I75W I70W 165* 160 W 155 W I50W 145 W 140 W 135 W I30W 125 W 120 W II5W 



Figure lb. — Average number of observations per month during summer seasons for 1961-71. 



3 



