Monday, 23 January 2012
Assimilation of Remotely Sensed AMSR-E and GlobSnow Snow Data in CaLDAS Land Assimilation System
Hall E (New Orleans Convention Center )
Snow cover and terrestrial snow processes have a crucial influence on heat fluxes between the land and atmosphere because of its high albedo and insulating thermal properties, which impact the energy and water balance on land. The snow water equivalent (SWE) and snow cover fraction (SCF) are of particular importance for accurate representation of sensible and latent heat fluxes in atmospheric model and of water availability in hydrological model. To account for this, an ensemble Kalman filter (EnKF) analysis scheme has been developed to include observed SWE and SCF into the Canadian Land Data Assimilation System (CaLDAS), to be proposed for operational implementation at the Canadian Meteorological Service. The main objective of this study is to include in CaLDAS daily 25-km SWE products from the Advanced Microwave Scanning Radiometer (AMSR-E). The impact of assimilating the daily AMSR-E SWE data for a period from November 2006 to April 2007 has been examined. A comparison with the SWE data derived from the Global Environmental Multiscale (GEM) land surface model has been done for a region over Western Canada (50o - 65o N latitude, 240o - 265o longitude) with 10 km resolution over the study area (forest, tundra and prairie). The error statistics of assimilation results compared with the in situ data over the region indicates good agreement of CaLDAS SWE analyses with observations. An overview of the efficiency of ensemble Kalman filter used within the CaLDAS system will be presented at the conference, as well as a subsequent assimilation study to compare the daily GlobSnow SWE data (25 km resolution), over the Northern hemisphere, for 2007, with the land surface model output. t the conference, as well as a subsequent assimilation study to compare the daily GlobSnow SWE data (25 km resolution), over the Northern hemisphere, for 2007, with the land surface model output.