950 
off from the subpolar cyclonic disturbances at such 
times and has a preponderance of fine weather. On the 
other hand, the meridional flow patterns of low index 
may be similar to an accentuated pattern of the April 
type, with intense low-latitude storms recurving into 
arctic areas. Much of the cold season storminess affect- 
ing northern arctic America is associated with this 
type of development which will occasionally equal or 
exceed the intensity of the autumn-type circulation 
anomaly. 
Spring Variations. The continuation of winter cold 
in the Arctic, while the continents are warming, results 
in exceptionally favorable conditions for anticyclonic 
developments over high-latitude arctic regions. April’s 
average circulation pattern is typical of the best spring 
weather, but anomalies in the general circulation may 
cause the April pattern to appear in March and again 
in May, with an April pattern resemblmg January’s 
strong circulation. An April anomaly of the above type 
does not seriously affect arctic America, except rarely 
when an Atlantic storm makes the polar circuit and 
approaches the Canadian Archipelago from the north- 
west. Variations of the winter low-index type are the 
more frequent and more serious circulation anomalies 
affecting arctic areas especially in early spring. 
ARCTIC METEOROLOGICAL PROBLEMS 
Observational Data. Because our knowledge is 
severely limited as to the relationship between the 
arctic tropospheric and stratospheric circulations them- 
selves, and because our understanding of the more 
general relationship between the arctic and the hemis- 
pheric circulation is by no means complete, it is difficult 
to visualize or suggest what might eventually constitute 
a representative coverage of arctic meteorological data. 
The problem of observational coverage was easier to 
resolve in 1945 when the synoptic reporting network 
for the North American Arctic was entirely inadequate. 
Since then the situation in that area has been greatly 
improved by the establishment of the new stations and 
by the weather reconnaissance described in the third 
section of this article. 
At this time the existing arctic weather station net- 
work (and the availability of data from these stations) 
is probably adequate for the preparation of routine 
synoptic analyses. However, the existing situation is 
not entirely satisfactory with respect to the availability 
of upper-air research data from the Eurasian Arctic. 
To solve this problem it will be necessary to achieve a 
higher degree of cooperation than apparently exists in 
the international exchange of current arctic meteorologi- 
cal data. Granting the relative adequacy of arctic 
tropospheric data, trends in current and planned 
meteorological research indicate that arctic soundings 
to altitudes well above 120,000 ft will be desirable when 
similar data from mid-latitude soundings to the ozono- 
sphere are available. These high-level observational 
data will be required in connection with the continua- 
tion and expansion of studies on the general atmospheric 
circulation, on its large-scale short- and long-period 
POLAR METEOROLOGY 
fluctuations, and on the possible linkage between solar 
activity and tropospheric meteorological phenomena. 
Synoptic Studies. Because of the short period for 
which relatively adequate data have been available, 
there are several aspects of arctic synoptic meteorology 
which have not received thorough consideration. Valu- 
able contributions to existing information should result 
from studies on the connections and interactions be- 
tween the state of the general circulation and semi- 
permanent systems, such as, the Aleutian low, Icelandic 
low, Siberian high, polar high, and North American 
high. 
There can be little doubt as to the desirability of 
undertaking further studies on the general circulation 
as regards that of the Arctic in relation to the tropo- 
spheric jet stream of middle latitudes. 
It also is suggested that another worth-while objec- 
tive for future investigations would be the compara- 
tively unknown nature and extent of control imposed on 
the arctic circulation by contrasts between continental 
and oceanic regions in the Arctic and in adjacent tem- 
perate areas. 
Basic Research. Investigations of a more fundamen- 
tal nature than the suggested and expected investiga- 
tions of synoptic relationships between arctic flow 
patterns and the hemispheric circulation will be under- 
taken because of the simple fact that the Arctic must 
necessarily be involved in much basic research on the 
dynamics of the earth’s atmosphere. An associated 
product of such studies will be the accomplishment of 
essential research on the interactions between arctic 
and middle-latitude regions with respect to transfer 
of mass, momentum, angular momentum or vorticity, 
entropy, heat content and moisture content, and the 
propagation of horizontal oscillations or perturbations 
between different latitudinal zones. Attainment of these 
research objectives would concurrently require solutions 
to the problem of heat balance and exchange by various 
causes, such as radiation, conduction, convection, ad- 
vection, and latent heat changes. 
REFERENCES 
1. Baur, F., ‘‘Das Klima der bisher erforschten Teile der 
Arktis.” Arktis, 2:77-89, 110-120 (1929). 
2. ByseRKNES, V., and others, Physikalische Hydrodynamtk. 
Berlin, J. Springer, 1933. (See Chaps. 14 and 15) 
3. Bronrman, L., On the Top of the World. London, Gollanez 
1938. (See pp. 244, 255) 
4. Byers, H., and Starr, V., ‘The Circulation of the At- 
mosphere in High Latitudes during Winter.’’ Mon. Wea. 
Rev. Wash., Supp. No. 47 (1941). 
5. Dorsey, H. G., Jr., “Some Meteorological Aspects of the 
Greenland Ice Cap.” J. Meteor., 2:135-142 (1945). 
6. DzervzErysxi, B. L., Tsirkuliatsionnye skhemy v troposfere 
Tsentral’noi Arktiki. Moskva, 
Nauk (SSSR), 1945. 
7. Henry, T. J. G., and Armsrrone, G. R., Aerological Data 
for Northern Canada, 271 pp. Dept. of Transport, Meteor. 
Div., Toronto, May 1949. 
8. Hosss, W. H., “Characteristics of the Inland-Ice of the 
Arctic Regions.’”? Proc. Amer. phil. Soc., 49:57-129 (1910). 
9. —— “The Greenland Glacial Anticyclone.” J. Meteor., 
2 :143-153 (1945). 
Izdatel’stvo Akademii _ 
= | ee eee 
