HR: 1330h
AN: C42A-1008    [PDF]
TI: The Impact of Snow-up Timing on Arctic Winter Soil Temperatures
AU: * Sturm, M
EM: msturm@crrel.usace.army.mil
AF: USA-Cold Regions Research Engineering Laboratory-Alaska, P.O. Box 35170, Ft. Wainwright, AK 99703 United States
AB: For ecosystems that are snow-covered during a significant part of the year, variations in the nature and timing of snow pack development can produce large year-to-year differences in the thermal regime of the soil. Here we use continuous snow-ground interface temperature measurements from two consecutive winters taken across a variety of vegetation types on the Seward Peninsula, Alaska, to quantify these differences. The first winter (2000-2001) had an above-average snow pack that was largely in place by November. The second winter had a below-average snow pack that did not develop until January. Interface temperatures the second winter averaged 10 to 20$\deg$C lower than the first despite similar air temperature regimes. Moreover, distinct differences in soil thermal regime that developed as a function of different vegetation types the first winter were largely absent in the second. The measurements also show that with increasing canopy height and stem diameter, the thermal regime of the soil is spatially more heterogeneous. The results suggest that larger changes in winter soil thermal regime can be induced through changes in the timing of the development of the winter snow pack than can be induced through step changes in winter air temperature.
DE: 0330 Geochemical cycles
DE: 0400 Biogeosciences
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2003 Fall Meeting