Geoscience Reference
In-Depth Information
World War II contained strong positive biases away from the North Atlantic sector
prior to the 1930s. Smaller errors are apparent up to 1939. As noted by P. Jones
(
1987
), these maps were prepared by relatively untrained analysts, who tended to
extrapolate into the data-poor Arctic with the concept of an Arctic high pressure cell
still in mind.
While the glacial anticyclone paradigm was seemingly put to rest in papers by
H. Dorsey (
1945
), F. Matthes (
1946
), and Matthes and A. Belmont (
1946
), Hobbs
continued to argue for the Greenland glacial anticyclone for several more years
(Hobbs,
1948
). Even in the early 1950s, some studies depicted cyclone activity as
largely restricted to the periphery of the Arctic Ocean (e.g., Pettersen,
1950
). This
view may have been influenced by Sverdrup's (
1933
) observations during the
Maud
Expedition (1918-1925) of the frequent passage of cyclones along the fringes of
the Arctic Ocean. In a topic chapter on Arctic climate published in 1958, F.K. Hare
makes use of S. Pettersen's (1950) map, which for both winter and summer depicts
most of the Arctic Ocean as a “Quiet Zone of Minimum Cyclonic Activity.” For
summer, Hare provides the following description:
The quiet central zone in summer coincides fairly closely with the permanent
pack ice of the Arctic Sea. Although a few frontal cyclones appear to cross it,
the prevailing state is one of monotonously slack and ill-defined circulation,
appropriate enough to what is certainly the world's largest quasi-homogeneous
surface. Only along the flanks does cyclonic cloud and rainfall become at all
common. (Hare,
1958
, p. 69)
But an epiphany soon followed. The emergence in North America of more modern
views of the Arctic circulation appears in the work of research groups at McGill
University led by Hare (Wilson,
1958
; Hare and Orvig,
1958
) and at the University
of Washington led by R. J. Reed (Keegan,
1958
; Reed and Kunkel,
1960
; Reed,
1962
). These studies showed that while anticyclones are common and often persis-
tent features, they are by no means permanent. It was also realized that cyclones can
be found anywhere in the Arctic and in all seasons.
In the Soviet Union, by contrast, a relatively modern view had already been for-
mulated in 1945 by B. Dzerdzeevskii (
1945
). This study, remarkable both for its
insight and in recognition of what must have been difficult wartime working condi-
tions, was based on data from the icebreaker
Sedov
, the first Soviet drifting ice sta-
tion, NP-1, and other observations. Dzerdzeevskii correctly concluded that cyclone
activity was common over the central Arctic Ocean during summer.
Turning to jet streams, fronts, and airmasses, conceptual models of the general
circulation through the 1950s and 1960s presented in studies such as those by E.
Palmén (
1951
), F. Defant and H. Taba (
1957
) and Palmén and C. Newton (
1969
)
featured a two-front structure associated with the subtropical and polar front jet
streams. This model can be traced back to the pioneering work by Bjerknes, Rossby
and others described earlier. In the 1950s, however, the Canadian Meteorological
Service adopted a three-front, three-jet stream, four-airmass model (Anderson,
