HR: 14:30h
AN: H13J-04    [Abstracts]
TI: Long-Term Evaluation of the AMSR-E Soil Moisture Product Over the Walnut Gulch Watershed, AZ
AU: * Bolten, J D
EM: jbolten@geol.sc.edu
AF: USDA ARS Hydrology and Remote Sensing Laboratory, Rm 104 Bldg 007 BARC-West, Beltsville, MD 20705 United States
AU: Jackson, T J
EM: tjackson@hydrolab.arsusda.gov
AF: USDA ARS Hydrology and Remote Sensing Laboratory, Rm 104 Bldg 007 BARC-West, Beltsville, MD 20705 United States
AU: Lakshmi, V
EM: vlakshmi@geol.sc.edu
AF: Department of Geological Sciences, University of South Carolina, 712 S. Main Street EWS 617 , Columbia, SC 29205 United States
AU: Cosh, M H
EM: mcosh@hydrolab.arsusda.gov
AF: USDA ARS Hydrology and Remote Sensing Laboratory, Rm 104 Bldg 007 BARC-West, Beltsville, MD 20705 United States
AU: Drusch, M
EM: m.drusch@ecmwf.int
AF: European Centre for Medium-range Weather Forcasts, Shinfield Park, Reading, RG2 9AX United Kingdom
AB: The Advanced Microwave Scanning Radiometer -Earth Observing System (AMSR-E) was launched aboard NASA's Aqua satellite on May 4th, 2002. Quantitative estimates of soil moisture using the AMSR-E provided data have required routine radiometric data calibration and validation using comparisons of satellite observations, extended targets and field campaigns. The currently applied NASA EOS Aqua ASMR-E soil moisture algorithm is based on a change detection approach using polarization ratios (PR) of the calibrated AMSR-E channel brightness temperatures. To date, the accuracy of the soil moisture algorithm has been investigated on short time scales during field campaigns such as the Soil Moisture Experiments in 2004 (SMEX04). Results have indicated self-consistency and calibration stability of the observed brightness temperatures; however the performance of the moisture retrieval algorithm has been poor. The primary objective of this study is to evaluate the quality of the current version of the AMSR-E soil moisture product for a three year period over the Walnut Gulch Experimental Watershed (150 km2) near Tombstone, AZ; the northern study area of SMEX04. This watershed is equipped with hourly and daily recording of precipitation, soil moisture and temperature via a network of raingages and a USDA-NRCS Soil Climate Analysis Network (SCAN) site. Surface wetting and drying are easily distinguished in this area due to the moderately-vegetated terrain and seasonally intense precipitation events. Validation of AMSR-E derived soil moisture is performed from June 2002 to June 2005 using watershed averages of precipitation, and soil moisture and temperature data from the SCAN site supported by a surface soil moisture network. Long-term assessment of soil moisture algorithm performance is investigated by comparing temporal variations of moisture estimates with seasonal changes and precipitation events. Further comparisons are made with a standard soil dataset from the European Centre for Medium-Range Weather Forecasts. The results of this research will contribute to a better characterization of the low biases and discrepancies currently observed in the AMSR-E soil moisture product.
DE: 1846 Model calibration (3333)
DE: 1855 Remote sensing (1640)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: Fall Meeting 2005