HR: 11:50h
AN: C12A-07    [Abstracts]
TI: Snowpack Radiative Heating: Influence on Tibetan Plateau Climate
AU: Zender, C S
EM: zender@uci.edu
AF: Earth System Science Department, University of California-Irvine, Croul Hall, Irvine, CA 92697-3100 United States
AU: * Flanner, M G
EM: mflanner@uci.edu
AF: Earth System Science Department, University of California-Irvine, Croul Hall, Irvine, CA 92697-3100 United States
AB: While solar absorption decays exponentially with depth in snowpacks, most climate models constrain all snowpack absorption to occur uniformly in the top-most snow layer. We show that 20-45 % of solar absorption by deep snowpacks occurs more than 2 cm beneath the surface, depending on snow grain size. Vertically-resolved snowpack heating induces daytime sub-surface temperature maxima and snow melt. Slight reductions in snow mass trigger strong snow-albedo feedback on the Tibetan Plateau, a unique region subject to intense winter insolation. Vertical redistribution of energy within the snow reduces winter snow mass on the Tibetan Plateau by ~80 % in one GCM, and significantly increases 2-meter air temperature. These changes significantly reduce model-measurement discrepancies of Tibetan Plateau climate and demonstrate the important role of snow-albedo feedback at regional scales. We also examine the impact of improved snowpack radiative treatment on seasonal soil moisture biases using AMSR-E data.
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 0798 Modeling
DE: 9320 Asia
SC: Cryosphere [C]
MN: Fall Meeting 2005