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distribution and characteristics of the polar marine climate have recently been
described in more detail by Ballinger et al. (
2013
).
Some investigators cite areas such as the Bering Strait and the coasts of the
Beaufort and Chukchi Seas as having maritime climates although winter tempera-
tures are much lower. Climatic conditions for Barrow, Alaska, have been discussed
extensively (e.g., Moritz,
1979
; Dingman et al.,
1980
; Shulski and Wendler,
2007
).
During the snow-free season along such coastal areas, there is often a rapid increase
of temperatures inland. This is seen clearly in the July mean field of surface air tem-
perature (
Figure 2.21
). Recall from
Chapter 4
that this coastal temperature gradient
extends through a considerable depth of the lower troposphere and defines the sum-
mer Arctic frontal zones.
8.3.2
Examples - Svalbard and Barrow
Following from this discussion, a good example of a maritime Arctic climate is
Isfjord Radio (Svalbard) (
Figure 8.9
). Note first the sharply higher winter air tem-
peratures as compared to Resolute Bay, the polar desert site (
Figure 8.6
). The max-
imum summer temperature, however, is similar at about 5°C. The sites also differ
strongly in terms of precipitation. Compared to the summer maximum at Resolute
Bay, Isfjord exhibits a distinct autumn/winter precipitation maximum and late
spring/early summer minimum. There is also a more even seasonal distribution of
cloud cover, ranging from about 60 percent in winter to 80 percent in August and
September. This manifests the Atlantic cyclone influences.
The precipitation regime is broadly similar to that of Iceland, well to the south.
During autumn/winter, the North Atlantic storm track is strong. Coupled with the
availability of abundant oceanic moisture sources and relatively high evaporation
rates, precipitation is high. Serreze and Etringer (
2003
) estimate that in the vicinity
of Iceland, about half of the mean January precipitation is contributed by the large-
scale vapor flux convergence and half by surface evaporation.
Figure 6.9
indicates that January mean P-ET in the Svalbard area, representative
of winter months, is quite small (0-10 mm). As the change in atmospheric water
vapor storage is also small at this time, P-ET is essentially the vapor flux conver-
gence (see
Chapter 6
for discussion of the aerological moisture budget). Because
the winter vapor flux convergence is so small in the vicinity of Svalbard, this indi-
cates that - compared to the Iceland region - correspondingly more of the winter
precipitation is derived from surface evaporation.
Extensive cloud cover, open water, latent heat release, and poleward heat fluxes
associated with frequent cyclone activity combine to keep winter surface tempera-
tures remarkably high given the latitude (roughly 80°N). The North Atlantic storm
track is weaker in summer. Because of the weaker temperature contrasts between the
ocean and lower atmosphere, surface evaporation declines. Precipitation-generating
mechanisms are therefore weaker than in winter. However, cloud cover is still exten-
sive, which moderates the surface air temperature. The June peak value in average
downward solar radiation (about 200 W m
−2
) is much lower than that for Resolute
