962 
markable excursion which maintained stations on both 
flanks as well as in mid-ice (Hismitte) for a calendar 
year. The Wegener results provide by far the most 
important evidences yet at hand concerning the icecap 
climate. In the same year an official British party es- 
tablished an icecap station on the east slope, rather 
to the south of the Wegener station. Thereafter there 
was a period of inactivity until the United States es- 
tablished stations during 1944. In 1949 a well-equipped 
French party led by P. E. Victor reoccupied the 
Eismitte site, resuming the Wegener observations on 
an enlarged scale. The station is still in operation (June, 
1950) and efforts are being made to keep it open for 
another year. 
As a result of these studies the consensus of meteorol- 
ogists is that the glacial anticyclone is in large measure 
based on a confusion of fact with deduction. To sum- 
marise the present position: v 
1. The radial wind system, the basis for Hobbs’s 
views, is more complex than early accounts allowed. 
Stations established on the slopes [40, 41] reveal that 
the surface wind most commonly flows downslope, but 
by no means invariably so. At the Hismitte station, 
where, according to Hobbs, the wind should have been 
light, variable, or easterly, the winds were actually 
strong [65]. All stations showed periods of upslope flow, 
and considerable variability was general. The Univer- 
sity of Michigan station on the west slope indicated 
that the outblowing winds might extend to 4 km 
(18,000 ft) or above [40, Part I]. 
The general view today is that the radial wind system 
is a katabatic circulation; the cooled air flows down 
the slope under gravity, eventually reaching sea level 
along the numerous fjords with which the coast 
abounds. General subsidence in the central regions of 
Greenland must occur to feed the katabatic flow. In 
this sense the term ‘“anticyclone” is faintly justified, 
since anticyclones are regions of subsiding air. In every 
other sense, however, the term is a complete misnomer. 
Several writers have expressed the opinion that the 
katabatic winds blow only during periods of feeble 
general circulation over the icecap. Dorsey [11], who 
operated the U. 8S. Icecap station during 1944, states 
that the katabatic winds are absent if there is an ap- 
preciable upslope component in the regional circulation. 
Much the same conclusion is drawn by Mirrlees [41]. 
Both these writers produce evidence that exceptionally 
strong flow down the east slope occurs in the rear 
quadrants of cyclones in the vicinity of Denmark Strait 
or Iceland; in other words, excessively strong ‘‘strophs” 
of icecap air require the joint action of the katabatic 
flow and a parallel regional flow. 
2. The alimentation of the cap by hoarfrost has 
been similarly disputed. Matthes [89], in a closely 
argued critique of Hobbs’s views, points out that the 
air subsiding into the central regions of the Greenland 
“anticyclone” can contain only negligible amounts of 
moisture; furthermore, it must have been rendered 
relatively drier by the adiabatic warming postulated 
by Hobbs. 
The condensation of rime (liquid cloud or cloud 
POLAR METEOROLOGY 
droplets frozen onto solid surfaces) is a well-known 
phenomenon in moist air masses. Mount Washington 
Observatory affords numerous striking and photogenic 
examples every winter. It is very possible that rime 
accretion is appreciable on the lower slopes of the 
Greenland cap. Hobbs, however, has specifically ruled 
that moist maritime air does not penetrate more than 
a few miles inland, and rime cannot possibly form from 
the subsiding air of the icecap. 
On the other hand, there is abundant evidence that 
there is frequent heavy snow on the icecap. Georgi 
[13, pp. 52-87], observer at Hismitte, was almost over- 
whelmed by the heavy snow of August 1930, when he 
established the station; Courtauld, hero of the cele- 
brated six-month vigil on the icecap of the British 
Arctic Air Route Expedition, was actually buried, and 
had to be rescued through the ventilating shaft of his 
quarters [41]. Moreover the periods of snow fell during 
spells of upslope winds, and were preceded by cloud 
sequences similar to those observed at lower levels dur- 
ing frontal passages. It is impossible to believe that 
experienced observers like Georgi and Courtauld could 
have confused snow and hoarfrost. 
Most of these observers concluded that cyclones 
could and did cross the icecap, and that the snow was 
normal cyclonic snow. Dorsey [11], however, felt that 
it was unrealistic to talk of sea-level pressure systems 
crossing a 10,000-ft barrier; he suggested, with con- 
vineing evidence, that it is the higher-level perturba- 
tion that overlies a surface cyclone that crosses the 
icecap. This is the mechanism, for example, by which 
Pacific cyclones appear to enter central North America 
across the Western Cordillera. Dorsey argued that it 
was the height of the barrier that blocked the free 
movement of cyclones, and not the presence of a fixed 
anticyclone. A similar blocking action is exerted by 
many mountain systems such as the Alps, the Pyrenees, 
and the Caucasus. 
An inspection of the remarkable observational dia- 
gram drawn up by Georgi [24] makes it impossible to 
doubt the force of these objections. The record shows 
the rapid fluctuations of pressure, temperature, and 
wind velocity typical of a disturbed cyclonic climate. 
To quote Georgi [13, p. 19]: “... the wind régime over 
the icecap is much more complicated than the simple 
model of the glacial anticyclone allows.” To a reader 
of Georgi’s diary this seems a conservative comment. 
3. Dorsey [11] has also pointed out the basic fallacy 
in Hobbs’s argument that the Greenland cap is the 
source of the cold waves which touch off the Northern 
Hemisphere’s chief cyclonic storms. It is true, he ad- 
mits, that the icecap air is the coldest in the hemisphere 
on a year-round basis. Potentially, however, it is much 
warmer than the air over, for example, Arctic Canada, 
and it loses its coldness when it descends to sea level. 
Actually, icecap air enters the circulation of the Atlantic 
very much warmer than the typical continental polar 
air masses of Canadian provenance. 
In sum, then, the idealised model of a glacial anti- 
cyclone appears quite inadequate to account for the 
observed facts; the theory has elements of the truth, 
