Physical and Optical Properties of Snow Covering Arctic Tundra
on Svalbard and Its Impact on Biota
Sebastian Gerland 1, Jan-Gunner Winther1, Jon Brre rbk2, Nils Are ritsland2, Al-
berto Blanco3, and Boris Ivanov4
Snow thickness, duration of snow coverage, and amount of soil covering ice are crucial for the
development of biota in the Arctic tundra environment. The snow thickness and optical properties
control the amount of Photosynthetic Active Radiation (PAR) that is available for vegetation. A
late snow cover may prevent birds from nesting on the ground. Furthermore, ice at the snow/soil
interface can be an obstacle for grazing of Svalbard reindeer and affect the microfauna popula-
tion.
Snow and ice thickness, physical and optical properties of snow covering Arctic tundra were
measured near Ny-lesund in the Kongsfjord area on the Brgger peninsula on Svalbard in
spring 1997. Ny-lesund is located at 79N latitude; however, due to the North Atlantic Current,
the regional climate is relatively mild. The initial maximum thickness of snow in the observed ar-
eas varied from 0.4 to 0.9 m. The snow around Ny-lesund began to disappear by the beginning
of June, with the entire snowpack melting within 23 weeks. At the bottom of the snowpack, we
found a 5- to 10-cm-thick ice layer covering the soil. Radiation and reflectance parameters (spec-
tral albedo, attenuation of PAR, and global radiation) were obtained as well as physical properties
of snow (e.g., temperature and density) over six weeks from early May to late June. Electrolytic
conductivity measurements on melted snow samples from snow pits showed different conductivi-
ty for different stratigraphic sections of the snowpack in early June. Later on, these contrasts dis-
appeared as internal ice layers melted and the snowpack underwent percolation. The albedo max-
imum before melt onset exceeded 0.9 (visible wavelength range), whereas in the later phase of
melting, snow surfaces exhibited significantly lower albedo due to metamorphosis, thinning, and
blackening by soil-particle contamination. However, even an apparently "clean" snow surface
had about 30% lower albedo in mid-June than in mid-May. We measured furthermore that PAR
radiation penetrates deeper into the snowpack after the onset of snowmelt than before. Conse-
quently, the radiation available for warming of the deeper part of the snowpack and for vegeta-
tion at the soil surface increases with time and the melting process might be accelerated.
1 Norwegian Polar Institute, 9005 Troms, Norway
2 Norwegian Polar Institute, P.O. Box 5072, 0301 Oslo, Norway
3 Department of Geophysics, University of Helsinki, P.O. Box 4, 00014 Helsinki, Finland
4 Arctic and Antarctic Research Institute Bering-38, 199397 St. Petersburg, Russia
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