HR: 1340h
AN: GC23A-0972    [Abstracts]
TI: Impact of Surface Air Temperature and Snow Cover Depth on the Upper Soil Temperature Variations in Russia
AU: * Sherstyukov, A B
EM: boris@meteo.ru
AF: All-Russian Research Institute of Hydrometeorological Information - World Data Center, 6 Koroleva Street, Obninsk, 249020, Russian Federation
AU: Sherstyukov, B G
EM: boris@meteo.ru
AF: All-Russian Research Institute of Hydrometeorological Information - World Data Center, 6 Koroleva Street, Obninsk, 249020, Russian Federation
AU: Groisman, P Y
AF: University Corp. for Atmospheric Research, NCDC, Federal Building, 151 Patton Avenue, Asheville, NC 28801, United States
AB: A study of the impact of climate changes during for the last four decades on soil temperatures at depths up to 3.2 meters has been conducted for the territory of Russia. For the 1965-2004 period, we compiled and analyzed data from all Russian meteorological stations with long-term soil temperature observations at depths 80, 160 and 320 cm. Traditionally, these stations also observe a complete set of standard meteorological variables (that include surface air temperature and extensive monitoring of snow cover characteristics). This allowed us to investigate the impact of surface air temperatures and snow depth variations on soil temperatures in the upper soil layer, to quantify it using statistical analyses of multi-dimensional 40-year-long time series at 164 locations throughout the country, and assess the representativeness of the obtained results. Three-dimensional spatial distributions of regression and correlation coefficients were mapped for warm and cold seasons separately as well as for the entire year, and thereafter analyzed. In the permafrost zone we found special features in these fields that distinctively separate the permafrost zone from the remaining territory. In this zone, soil temperatures are practically uncorrelated with surface air temperatures and variations of the snow depth controls soil temperature variations (with R² up to 0.5) Quantitative estimates of the contribution of mid-annual air temperature and snow cover depth in the long-term changes of mid-annual soil temperatures across the Russia territory were received. We found that the prevailing influence on soil temperature variations in the European part was surface air temperatures and in the Asian part of Russia was snow cover depth. Furthermore, increase of the winter snow depth in the permafrost zone (by preserving the heat accumulated in the warm season) promotes annual soil temperature increase and therefore may foster the further permafrost degradation associated with ongoing regional warming.
DE: 0702 Permafrost (0475)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting