Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 25, 2010
Publication Date: September 30, 2010
Citation: Holmes, T.R., Jackson, T.J., Crow, W.T., De Jeu, R. 2010. A multi satellite temperature product for the interpretation of L Band observations [abstract]. 2010 IAHS Remote Sensing and Hydrology Symposium. p. 82. Technical Abstract: It is well known that microwave soil moisture retrieval algorithms must account for the physical temperature of the emitting surface, and many approaches now make use of high frequency temperature estimates, specifically 37 GHz (Ka-band). The two L-band soil moisture missions, Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP), will not include a 37 GHz (Ka-band) microwave radiometer. Therefore, alternative algorithms and data sources must be utilized. The current approach is to use the temperature output from numerical weather prediction (NWP) models. In a recent study, the accuracy of NWP analysis data was analyzed in terms of land surface temperature. Of the sources considered, the Modern Era Retrospective-analysis for Research and Applications (MERRA), was found to have the best performance with an absolute accuracy of 2.0 K (RMS error) in the morning, with a bias removed error of 1.5 K. The relationship between the error in soil temperature data and the requirements of the radiative transfer and soil moisture retrieval algorithm temperature requirements are assessed recently. For a single channel soil moisture retrieval, a 1.5 K error in temperature results in an error of up to 0.03 m3m-3 in soil moisture (at the highest vegetation level within the SMAP requirements). Therefore, the level of accuracy of a single NWP temperature product is not likely to be high enough to achieve the stated goals of 0.04 m3m-3 for the retrieved soil moisture products from SMAP and SMOS. The goal of this study is to combine a single NWP soil temperature product with Ka-band observations from multiple satellites in an attempt to increase the accuracy of the combined product to a level that is suitable with the SMAP and SMOS mission requirements. This combined temperature product will be used to model the effective temperature for SMOS, and can be used to demonstrate the effect on the retrieved soil moisture fields for several SMOS swaths.