THE PHYSICAL BASIS FOR THE GENERAL CIRCULATION 
By VICTOR P. STARR 
Massachusetts Institute of Technology 
Since time immemorial man has inescapably observed 
the atmosphere in which he lives and has his being. 
It would therefore seem reasonable to expect that at 
the present date the science of meteorology should be 
one of the most advanced fields of human endeavor. 
Yet, if a distinction is made between the mere collec- 
tion of descriptive facts of observation on the one hand 
and interpretative work which aims to give a rational 
intellectual understanding of phenomena on the other, 
it must be confessed that our knowledge concerning 
the large-scale motions of the atmosphere is restricted 
mostly to the former category of information. Thus, 
for example, no one has as yet given a satisfactory 
rational explanation for one of the most outstanding 
features of the general circulation, namely the large 
belts of westerly winds in the temperate latitudes of 
each hemisphere. However, it must be recognized that 
it is only in the last few decades that anything ap- 
proaching sufficiently complete global observations for 
the checking of hypotheses regarding the general circu- 
lation has become available, so that progress’ at a 
more accelerated pace should now be forthcoming. 
The physiognomy of present-day meteorology bears 
much of the imprint imparted to it by the (so to speak) 
accidental way in which synoptic reporting networks 
developed and grew. In fairly recent times it was quite 
an achievement for a meteorologist to have at his 
command a network of reports large enough to depict 
an entire cyclone. The immediate temptation was then 
to treat this feature as an independent entity and to 
separate it artificially from its meteorological environ- 
ment in seeking a rational explanation for it. The 
cyclone thus became a phenomenon that existed inde- 
pendently. More extensive observations now available 
point to the inadequacy of this tacit assumption. The 
cyclone constitutes a cogwheel in a larger mechanism 
and probably can be understood only in relation to 
and not independent of its atmospheric context. 
A criticism which is the same in principle can be 
leveled against many other efforts to explain synoptic 
structures. Indeed meteorology is replete with attempts 
to formulate ad hoc explanations for individual details 
of the general circulation without due cognizance of 
their role as functioning parts of a global scheme. 
In the more recent literature there are signs that we 
are outgrowing this restricted point of view; there are 
indications which emphasize the essential oneness of 
the atmosphere which must be studied as an internally 
integrated and coordinated unit. The general circula- 
tion presents a puzzle to be solved. We must learn 
how the various parts fit together into a whole if we are 
to understand it. With the hemispherical data now be- 
coming available and the clues already at our disposal 
the avenue to sound progress is wide open and, at 
least as far as the writer is concerned, quite inviting. 
It is therefore in the spirit of appraising our knowl- 
edge from the larger point of view that this commentary 
is written. Admittedly and intentionally the treatment 
reflects the writer’s viewpoint gained through a number 
of years of concentration on the subject under con- 
sideration. As a candid personal sidelight it should be 
mentioned, however, that much of the material is in 
a sense a relatively recent culmination of the writer’s 
striving toward a more unified and coherent conception 
of the global circulation. Nor is there currently any 
sign that this process has reached a state of final crys- 
tallization. This paper is therefore in the nature of an 
individualistic progress report designed to portray and 
to share with others a certain outlook and approach 
in the hope that really substantial and enduring prog- 
ress may eventually be attained thereby. Within the 
space of these pages we cannot hope to give anything 
approaching an exhaustive exposition of various topics. 
For this reason only certain basically important high- 
lights will be elaborated, and we shall rely upon the 
reader’s competence to interpolate various items of 
information which are generally available in the litera- 
ture. Furthermore, the selection of the subjects touched 
upon is not one dictated by an aim at logical com- 
pleteness, but rather is limited to those aspects which 
in the writer’s mind are most likely to be conducive to 
further results at the present stage of development of 
the science. 
As an outstanding problem of paramount importance 
for human activities, it is rather astonishing that the 
global circulation of the atmosphere has not up to the 
present time received more consideration from physical 
scientists generally. This situation is probably due in 
part to the lack of proper observational information so 
necessary for the successful prosecution of research 
concerning the subject. The gaps in at least our gross 
factual information are currently being removed rather 
rapidly, with the consequence that questions regarding 
the proper interpretation of the data begin to be the 
major issues. We might, with benefit in this connection, 
digress for a moment and compare the development of 
meteorology with that of another physical science, 
namely astronomy. No one can dispute the claims that 
Galileo and Newton created a new and orderly con- 
ception of the solar system. This achievement was 
necessarily preceded not only by the laborious accumu- 
lation of observational knowledge by Tycho Brahe and 
others but also by the proper interpretation of these 
data by Kepler who, it might be said, defined in pre- 
cise terms the dynamic puzzle to be resolved. In me- 
teorology we find ourselves in what might be called 
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