The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners.
As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
i
Downscaling advanced microwave scanning radiometer (AMSR-E) soil moisture retrievals using a multiple time-scale exponential rainfall adjustment technique
-
2015
-
Source: J. Geophys. Remote Sens., 4(1), 1-15.
[PDF-1.96 MB]
Details:
-
Journal Title:Journal of Remote Sensing & GIS
-
Personal Author:
-
NOAA Program & Office:
-
Description:Hydrologic response at all resolutions is controlled by physical processes. Accurately capturing the physical process
at a high-resolution is essential for down scaling many satellite observations at coarse resolutions. In this paper, a
four-dimensional process representative soil moisture downscaling model is developed to downscale the Advanced
Microwave Scanning Radiometer-EOS (AMSR-E) 25 km resolution soil moisture product. The model is composed of
the calculation of an antecedent precipitation accumulation (APA) index to capture soil moisture spatial and temporal
variations at the 500 m resolution, and the application of a Geographic Information System (GIS) to simulate physical
processes which can regulate soil moisture changes throughout the watersheds. APA index, as a representation of
the provisional value of soil moisture, is calculated by adopting an exponential formulation to synthesize the effects of
infiltration, soil evaporative efficiency, and vegetation resistance on soil water content following precipitation. Five days
of AMSR-E soil moisture derivatives spanning the start of the monsoon and the duration of the storm are selected for
downscaling. The results show that soil moisture spatial variation is primarily controlled by the distribution of precipitation
and soil properties. Subsequently relative soil moisture, radiation, and vegetation become significant in controlling landsurface
fluxes and thus influence soil moisture variation as time progresses. The downscaled soil moisture data (500
m resolution) are assessed using in-situ soil moisture measurements from the National Oceanic and Atmospheric
Administration (NOAA) Hydrometeorology Testbed (HMT) and the U.S. Department of Agriculture (USDA) Southwest
Watershed Research Center (SWRC) Walnut Gulch Experimental Watershed (WGEW) observing networks. The root
mean square error (RMSE) between the disaggregated and in-situ soil moisture is 0.034 vol./vol. with percent bias
(PBIAS) 0.85%. The overall R2 value is 0.788.
-
Source:J. Geophys. Remote Sens., 4(1), 1-15.
-
DOI:
-
Document Type:
-
Rights Information:CC BY
-
Compliance:Submitted
-
Main Document Checksum:
-
Download URL:
-
File Type:
