Testing AMSR-E Snow Retrievals With Cold Lands Processes Experiment Data
Abstract
Snow cover is an important component of the global hydrological cycle. Not only does it constitute a critical seasonal and long-term storage factor but it also affects global climate mass and energy dynamics. Accurate estimation of snow mass is important, therefore, for effective characterization of the hydrological cycle at different space and time scales. Satellite passive microwave observations have been used to estimate global snow depth and snow water equivalent (SWE) since 1979. However, during this time the instruments available have been able to observe snow mass over spatial domains only at regional scales; finer scale observations have not been possible. The Advanced Microwave Scanning Radiometer - EOS launched in 2002 aboard NASA's Aqua platform, has improved spatial resolution capabilities compared with previous passive microwave instruments and, potentially, can be used to estimate snow depth and SWE with increased accuracy at the regional scale. The Cold Lands Processes Experiment (CLPX) provides an opportunity to examine the spatial variability of snow mass and to determine controls on its observability by AMSR-E in complex and simple terrains. This paper investigates the characteristics of AMSR-E retrievals of SWE in the CLPX study domain. Level 2A AMSR-E estimates of SWE at the 25 x 25 km Equal Area Scaleable grid (EASE grid) are used in the study. The three Mesocell Study Areas (MSA), North Park, Fraser and Rabbit Ears Pass, are used as the spatial framework and data from the intensive observing periods during February and March 2003 are used for testing the AMSR-E retrievals. Field measurements of SWE from the ground campaign are compared with AMSR-E estimates. In North Park MSA, extensive SWE field surveys were conducted within the entire 25 x 25 km MSA to enable the characterization of SWE variability at the AMSR-E grid scale. For the other two MSAs, only intensive study area measurements were made and these data cannot be used to represent the average SWE at the AMSR-E scale of observing. The Polarimetric Scanning Radiometer (PSR), a passive microwave radiometer with similar AMSR-E channel frequencies, was flown aboard the NASA P-3 aircraft during the 2003 study periods. Data from this instrument has a spatial resolution varying from 100-500 m (depending on local terrain conditions). These data, calibrated with ground measurements, over all three MSAs, are used to test the AMSR-E retrievals of SWE and to help further improve our understanding and accuracy of estimates of SWE from AMSR-E.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.C42B..03K
- Keywords:
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- 1863 Snow and ice (1827)