HR: 14:00h
AN: H33C-03    [Abstracts]
TI: Validation of Retrieved Soil Moisture From AMSR-E Brightness Temperatures Over the SMEX02 Domain
AU: * Laymon, C
EM: charles.laymon@msfc.nasa.gov
AF: Global Hydrology and Climate Center, 320 Sparkman Dr., Huntsville, AL 35805 United States
AU: Crosson, W
EM: bill.crosson@msfc.nasa.gov
AF: Global Hydrology and Climate Center, 320 Sparkman Dr., Huntsville, AL 35805 United States
AU: Limaye, A
EM: ashutosh.limaye@msfc.nasa.gov
AF: Global Hydrology and Climate Center, 320 Sparkman Dr., Huntsville, AL 35805 United States
AB: A coupled hydrologic/radiobrightness model (H/RM) is utilized to estimate brightness temperatures at C and X bands and associated soil moisture for validation of soil moisture retrieved from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). This study is focused on the SMEX02 study area in central Iowa. The oversampling of the AMSR-E instrument is exploited in an optimization algorithm to deconvolve the brightness temperature observations for each EASEgrid cell. In so doing, the influence from adjacent grid cells is much less than with conventional spatial analysis schemes. The high spatial and temporal resolution of H/RM modeling relative to AMSR-E observations permits a statistical assessment of subgrid-scale characteristics. These results are combined with a sensitivity study of parameters used in the radiobrightness model to derive error statistics for the AMSR-E retrievals. In addition, we examine other sources of operational validation errors, such as, a) the errors associated with using limited gravimetric soil moisture data or point-scale measurements of soil moisture from network stations to estimate footprint-scale mean soil moisture, b) the errors associated with asynchronous sampling times, and c) the relationship between surface moisture (~1 cm) and profile moisture. These analyses are necessary to characterize the accuracy of the AMSR data products at EASE-grid scale. Although AMSR-E C band brightness temperatures are contaminated with radio frequency interference over the continental U.S., H/RM-estimated C and X band brightness temperatures are examined comparatively to reevaluate the value of C band retrievals elsewhere.
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2005 Joint Assembly