LARGE-SCALE ASPECTS OF ENERGY TRANSFORMATION OVER THE OCEANS 
By WOODROW C. JACOBS 
Headquarters, Air Weather Service, Washington, D. C. 
INTRODUCTION 
There has been a recent and encouraging re-em- 
phasis on investigations which involve some phase of 
the terrestrial heat budget, and the steadily accumu- 
lating number of investigations on the subject has 
brought proof that many meteorological and clima- 
tological problems can be wholly or partially solved 
through a consideration of energy transformation 
processes. In nearly all cases the purpose of the in- 
Quiries has been to ascertain the order of magnitude 
of one or more of the following components of the 
heat budget: 
1. Radiative balance between the sun, earth, space, 
clouds, and atmosphere. This includes separate con- 
siderations of the solar constant and of the reflection, 
scattering, absorption, and emission of radiant en- 
ergy by the earth’s surface, clouds, and turbid (moist) 
atmosphere. 5 
2. Exchange of sensible heat between the surface 
and the atmosphere. 
3. Heat used for evaporation (or melting). 
4. Heat realized through condensation 
freezing). 
5. Heat produced through dissipation of kinetic 
and gravitational potential energy in the atmosphere 
(and ocean). 
6. Transport of heat by ocean currents. 
7. Lateral and vertical transport of real heat and 
latent heat (as water vapor) by the atmosphere. 
8. Transfer of heat through conduction in the 
earth’s surface (or through vertical mixing and layer 
transmission in the case of water bodies). 
9. Changes in the internal energy of the atmos- 
phere and of the surface layers of land and oceans. 
Unfortunately, all of these factors in the energy 
budget of the earth and atmosphere are highly in- 
terdependent, a fact which renders their numerical 
computation exceedingly laborious. This is especially 
true if, instead of applying to average conditions, 
the evaluations are carried out for particular large- 
scale situations. It is because of this complexity that 
most of the general solutions to the large-scale prob- 
lems which have been presented to date are greatly 
simplified and apply to average annual conditions 
and most often to global zones rather than to specific 
geographic areas. Nevertheless, a knowledge of the 
basic causes of space and time variations in tempera- 
ture, humidity, pressure, winds, precipitation, and 
nearly everything else that contributes to the sum 
total of both weather and climate is obviously of 
fundamental importance in meteorology. Hence it is 
imperative that some consideration be given to the 
heat energy necessary to these conditions, its sources, 
(or 
when and where it is delivered, and how it is dis- 
tributed. 
Because additional details on energy transforma- 
tion processes are covered elsewhere in this volume, 
the following discussion is limited to several narrow 
but important phases of the problem. The field of 
application covers only the ocean areas of the globe. 
The discussion is further restricted to cover only the 
large-scale and more or less long-term (average) as- 
pects of the convective transfer of energy between sea 
surface and atmosphere. Space does not permit con- 
sideration of the radiative flux of heat energy be- 
tween sea and atmosphere, nor are the short-term or 
“synoptic”? aspects covered except as they are men- 
tioned among the recommendations for future re- 
search. 
Classical meteorological literature is replete with 
references to the profound effect of the oceans on 
world weather and climate. The moderating influence 
of oceans on the climates at high latitudes and par- 
ticularly on the west coasts of continents has long 
been recognized, but steps to evaluate the “effects” 
have consisted largely of attempts to compare or 
classify the local climates on the basis of “‘maritime- 
ness” or ‘“‘continentality.”’ Not until recently have 
serious efforts been made to evaluate the sea surface 
as a heat and moisture source and to demonstrate 
the role of the oceans in supplying energy for initi- 
ating and maintaining the general circulation of the 
atmosphere. When it is considered that the oceans 
comprise seventy-one per cent of the earth’s surface— 
the surface from which the atmosphere receives by 
conduction and radiation all but a small fraction of 
its total heat energy—and that the oceans are the 
prime source of moisture for all atmospheric proc- 
esses induced by water vapor, it is not unreasonable 
to expect that a solution to the problem of ocean- 
atmosphere energy relationships will carry the 
meteorologist a long way toward achieving a full 
understanding of the terrestrial energy budget. Un- 
fortunately, the investigators who have dealt with the 
large-scale aspects of the problem are few in number, 
and the meager results of their studies have been 
presented in something less than a dozen brief papers. 
For this reason the author hopes he will be forgiven 
if in the following discussion he appears to make ex- 
cessive reference to some of his own work along this 
line. 
RATE OF EXCHANGE OF SENSIBLE 
HEAT BETWEEN SEA SURFACE 
AND ATMOSPHERE 
Most of the earlier attempts to evaluate the rate 
at which sensible heat is conducted to the atmosphere 
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