This proposal is for continuation as a team member of Aqua AMSR-E for the derived soil moisture product algorithm refinement, maintenance, and science applications. The proposal is a combination of the types listed in Sections 3.1 and 3.2 of the NRA. Since the original ATBD algorithm development there have been significant revisions to the soil moisture algorithm, driven largely by the need to avoid radio frequency interference (RFI) in the 6.9 GHz channels of AMSR-E. The current algorithm uses the 10.7 GHz and higher frequency channels to estimate soil moisture, with corrections for perturbing factors (vegetation and surface roughness). The soil moisture product using this algorithm has been evaluated in field campaigns as well as in model assimilation studies. In this proposal we intend to continue to upgrade this algorithm by estimating and removing biases in the product and reducing its sensitivity to seasonal variability in vegetation. We also intend to produce a retrospective surface emissivity product at the AMSR-E frequencies. The algorithms for deriving surface emissivity and soil moisture will be applied to retrospective Nimbus-7 SMMR data as well as to AMSR-E to provide a long term climatological record of these quantities. This requires accurate cross-calibration of the sensors. These products will be evaluated for their potential to become Earth System Data Records (ESDRs) due to their key role in detecting and understanding change in the Earth system. The products will form a unified and coherent set of observations, optimized to meet specific requirements of hydrology and climate, and for addressing applications questions related to drought and flood forecasting. The data records are critical to assessing variability and long-term trends in surface moisture, and provide input and validation means to modeling efforts. These measurements will be continued during the NPOESS era at such time as a follow-on passive microwave sensor to AMSR-E may be flown, and the methods applied here will ensure continuity in product quality and validation across platforms from Aqua to NPOESS and beyond.
