HR: 1340h
AN: C13B-0269    [Abstracts]
TI: Mapping the Distribution of Seasonally Frozen Ground in the Northern Hemisphere
AU: * Zhang, T
EM: tzhang@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado, Boulder, CO 80309-0449 United States
AU: Frauenfeld, O W
EM: oliverf@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado, Boulder, CO 80309-0449 United States
AU: McCreight, J L
EM: mccreigh@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado, Boulder, CO 80309-0449 United States
AU: Barry, R G
EM: rbarry@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado, Boulder, CO 80309-0449 United States
AB: Seasonal freezing and thawing processes of soils have a great impact on surface energy balance, hydrological cycle, carbon exchange, and serious natural hazard at high latitudes. Areal extent of seasonally frozen ground is greater than any other major cryospheric components (such as seasonal snow cover, sea ice, permafrost, ice sheets, and glaciers). However, study on seasonally frozen ground has received little attention. We will give a brief review on study of seasonally frozen ground in the past decades. We will map annual distribution of seasonally frozen ground using annual freezing index of air temperature. Based on annual freezing index, we will estimate the potential maximum freezing depth at each grid pixel and areal extent of seasonally frozen ground in the Northern Hemisphere. We will further investigate inter-annual/inter-decadal variability of areal extent of seasonally frozen ground in the Northern Hemisphere. Annual freezing index of air temperature will be calculated based on daily ERA-40 reanalysis data. Over the contiguous United States, annual freezing index will also be calculated based on gridded daily air temperature using ground-based measurements. Comparison of the results from two data sets will be conducted to evaluate the accuracy of the ERA-40 reanalysis data over the contiguous United States and its applicability in the Northern Hemisphere.
DE: 3322 Land/atmosphere interactions
DE: 3344 Paleoclimatology
DE: 1823 Frozen ground
DE: 1863 Snow and ice (1827)
DE: 1615 Biogeochemical processes (4805)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting