ARCTIC METEOROLOGY 
original daily charts. There were little data in high 
latitudes to restrict most of the original analysts, who 
seem to have had a fairly uniform tendency toward 
overemphasis of arctic anticyclones. 
Petterssen [14] has good sea-level and upper-air pres- 
sure charts for January and July, but meteorologists 
must refer back to Sverdrup [19] for realistic seasonal 
pressure patterns, unless the new charts by Dzerdzeev- 
skii [6] become more readily accessible. Dzerdzeevskii 
analyzed the data obtained by the Russian Polar Ex- 
pedition, 1937-88, and included the results of previous 
studies in a new investigation of circulation patterns 
in the central Arctic. He shows that intense cyclonic 
and frontal activity was encountered near the Pole, and 
that the coldest air came from the American Arctic. 
His monthly average sea-level pressure charts are gen- 
erally similar to those of Baur and Sverdrup, but fail 
to account completely for the midwinter secondary 
minimum in pressure over northern arctic America. 
In 1949 an important study of the upper air over 
northern Canada was published by Henry and Arm- 
strong of the Canadian Meteorological Service [7]. Using 
the data collected from the new aerological stations set 
up in the Canadian Arctic under the joint United 
States-Canadian program, the authors have carried 
out an exhaustive climatological analysis. Isotherms 
and contours are shown in map form for the 850-, 700-, 
500-, and 300-mb surfaces for January, April, July, and 
October. The maps cover the greater part of Canada, 
including the Archipelago. Tabulated upper-air data 
are given for all stations, not only for the average year, 
but for each individual year of the record. Finally, 
there is an excellent discussion of the mean circulation 
over the Canadian Arctic. The work represents the 
most ambitious attempt yet published to clarify our 
picture of the circulation on the American side of the 
Arctic. 
OPPOSED CONCEPTS OF ARCTIC 
CIRCULATION PATTERNS 
It is difficult to believe that cooperating groups of 
modern scientists, such as meteorologists and explorer- 
geographers, could have sharply contrasting concepts 
of the Arctic, yet that rather surprising contention has 
been repeatedly expressed by Professor Hobbs. His 
restatement in 1948 of this viewpoint [10] was based 
on concepts of the atmospheric circulation patterns over 
two different arctic regions. Meteorologists have rarely 
published refutations of his contentions, but since his 
unacceptable theories have received wide publicity it 
now seems highly desirable to compare the meteor- 
ologists’ concept of the Arctic with that ascribed to 
them by his analysis of supposedly contrasting con- 
cepts. The arctic data used by meteorologists and 
climatologists have been gleaned from expedition re- 
ports wherever required to supplement those from fixed 
stations. No conflict exists and no contrast can be 
found between explorers and meteorologists in this 
matter, despite Hobbs’s statements to the contrary. 
While it has often been impossible to incorporate the 
roving explorer’s data into current weather maps, these 
943 
hard-won data have always been considered in thorough 
investigations of regional characteristics. Indeed, dur- 
ing the last two decades and even today, a major pro- 
portion of all field journeys into the Arctic and the 
Antarctic have had meteorological objectives. 
Characteristics of the Central Arctic Basin. Since 
meteorologists and other scientists familiar with the 
atmospheric circulation of the Northern Hemisphere 
know that the contimental interior regions of Canada 
and Siberia supply the polar air for the intense fronto- 
genetic zones off the east coasts of North America and 
Asia, with Greenland’‘and the arctic ice fields acting 
as secondary source regions because of the lesser con- 
trasts at high latitudes, there is no clear reason for 
Hobbs’s reference to Bjerknes [10], ‘‘... the hypothesis 
of the North Polar Front, or polar anticyclone, above 
the Arctic Basin was, at the time of its promulgation, 
contrary to all that had then been learned concerning 
its climate....’’ Over western Europe, Bjerknes’ polar 
“high” is rarely an anticyclonic cell from the North 
Pole, but is more likely to be developed from an anti- 
cyclonic circulation m maritime polar air over the 
North Atlantic Ocean or in an extreme westward flow 
of continental polar air from Eurasia. 
A remark that Nansen was able to confirm the Helm- 
holtz theory would appear to be counter to all of 
Hobbs’s elaboration on mean annual air pressure as 
observed by explorers in and about the Central Arctic 
Basin [10], but that is not imtended nor is any such 
implication required to aid in the elimination of imagi- 
nary controversies between explorers and meteor- 
ologists. While meteorologists prefer to deal with 
average pressures on a monthly, semimonthly, ten-day, 
or five-day basis when analyzing atmospheric circula- 
tion patterns, they are quite ready to accept Hobbs’s 
emphasis on the fact that the “normal” pressure isobar 
of ‘1013 millibars surrounds the Central Polar basin” 
[10]. Thereby he has shown it to be the area of relatively 
high pressure that Helmholtz anticipated, and with 
which meteorologists are familiar. This is true because 
what is “normal” pressure for the temperate zone is 
relatively “high” pressure north of the almost globe- 
circling belts of lower pressure associated with the 
Aleutian and Icelandic centers of cyclonic activity im 
winter, and with their related but westward displaced 
centers over northern Siberia and Canada in summer. 
On profiles of Northern Hemisphere pressure the 
latitude of minimum pressure averages about 62°N 
when taken on an annual basis. Much of the winter 
contribution to the higher pressure north of 60°N comes 
from the North American anticyclone in the Yukon 
territory, and from part of the Siberian anticyclone. 
Only in early autumn, in late spring, and in summer, 
when the Arctic Basin is colder than continental areas, 
is there a relatively strong arctic anticyclone with pres- 
sures consistently higher than over polar continental 
areas. In summer the North Pole itself is more often in 
a weak trough or ridge situation between ‘‘lows’’ over 
northern Baffin Bay and the Laptey-Kara Sea areas, 
or between “highs” cresting over the Spitsbergen- 
