One of the most important outcomes of the winter climate of the Arctic
Slope is the creation of a snow cover. This snow cover protects and
insulates the ground and low-lying plants, reduces desiccation, and
maintains ground temperatures that range from 5 to 30C higher than air
temperatures. Active-layer thickness and spring snowmelt run-off, often
the peak discharge of the year, all depend on the amount and distribution
of the snow. In addition, the formation of a snow cover protects the frag-
ile tundra from disturbance by human activity such as seismic explora-
It has become increasingly apparent that biological processes with cli-
matic significance do not completely cease during the cold season. For
example, microbial decomposition and CO2 production continue well
after the cold season has started (Clein and Schimel 1995, Fahnestock et
al. 1998, Zimov et al. 1993).
One of the most obvious Arctic climate feedbacks results from the differ-
ing albedoes of snow-covered vs. bare tundra. The timing of snowfall
events and the subsequent redistribution and weathering of snow by the
wind determines the small-scale "patchiness" observed during the thaw.
This mosaic of bare and snow-covered tundra has a significant effect on
local radiation budgets (Dingman et al. 1980, Kane et al. 1991, Liston
The cold season has a large impact on humans living and working on the
Arctic Slope. As the surface freezes and the snow cover develops, over-
land transportation becomes easier and less destructive because the tun-
dra is covered.
As is the case with much of Alaska, Arctic Slope communities and facilities
with a significant period of climate record are located either on the coast (e.g.
Barrow, Prudhoe Bay, and Wainwright), on islands (e.g. Barter Island), or in
immediate proximity to rivers (e.g., Atqasak, Umiat, and Nuiqsit). The National
Weather Service operates only five permanent weather stations on the Arctic
Slope, four of which are located within a few kilometers of the coast. Analysis of
these records tends to bias the result, rather than giving a picture of Arctic Slope
climate as a whole. This bias is compounded by the ubiquitous near-surface tem-
perature inversions commonly found at high latitudes during the Arctic winter.
The accompanying thermal stability strongly inhibits vertical mixing of momen-
tum and makes possible an extremely variable local microclimate that can bias
the climate record. This, in combination with terrain influences, can produce
local conditions, particularly wind direction, that are in direct opposition to large-
scale patterns (e.g., Haugen et al. 1976, Schwerdfeger 1973).