114 MALKUS [chap. 4 



to determine heat, water and momentnm exchanges between sea and air for 

 jDeriods from hours up to yearly averages is, in fact, a major cornerstone upon 

 which the present-day foundations of marine meteorology are built. Further- 

 more, the functional relation that these formulas prescribe between air-sea 

 property difference and wind speed provides a key to the role played by the air 

 circulation features in regulating their own energy sources, and thus lies very 

 close to the heart of planetary circulation dynamics on a wide range of scales. 



4. Climatology of Energy Exchange and the Global Heat and Water Budgets 



In this section, we shall first present mean annual distributions ofQe and Qs, 

 the latent and sensible heat fluxes from sea to air, and then the other heat- 

 balance components (equation (1)) of the ocean surface. The resulting annual 

 heat budget of the ocean forms a foundation for discussing the global heat and 

 water budgets, the climatological picture of exchange and its average seasonal 

 variations in selected regions. We thus develop a quantitative description of the 

 operation of the whole system and the function played by the various parts 

 of the sea and air in its machinery ; the remaining sections will consider the 

 mechanisms of the described energy transactions and their implications to 

 circulation energetics and dynamics. 



A . Mean Annual Distribution of Latent and Sensible Heat Exchange 



The basic materials for this discussion are the recent Russian calculations of 

 Qe and Qs and the other heat-balance components over the oceans (Budyko, 

 1955, 1956; Drozdov, 1953) and their comparison with determinations by 

 Jacobs (1951a), Sverdrup (1957), London (1957), Houghton (1954) and others. 



Annual mean maps of the geographic distribution of Qe and Qs after Budyko 

 are shown in Figs. 7 and 8. Similar maps for each month are available in the 

 Atlas of the Heat Balance (Budyko, 1955) but are not reproduced here. Depart- 

 ures of these mean annual values from those of Jacobs are indicated in Tables 

 III and IV. Table V gives the corresponding values of the Bowen ratio {r = 

 QslQe)- Particularly in the case ofQe {LE where E is evaporation), the departures 

 are gratifyingly small. Fig. 4 compared the globally integrated evaporation 

 figures by all authors available to date. The closeness of all four curves suggests 

 there is little disagreement in determinations of mean annual evaporation and 

 its variation with latitude. 



Since Jacobs and Budyko both used the transfer formula method for their 

 determinations of Qe, with a leading coefficient differing by only a few per cent, 

 the discrepancies in Tables III-V are probably attributable to differences in 

 the climatological mean values of air-sea property difference and wind speed 

 used. Since many years have elapsed between the two sets of evaluations, it is 

 possible that the discrepancies at least partially represent real time changes in 

 the parameters. It is interesting to note that among the greatest departures are 

 the much higher turbulent heat transfers reported by Budyko in the North 



