Millimeter Wave Moisture Sounder Feasibility Study: The Effect of Cloud and Precipitation on Moisture Retrievals

A simulation model applicable to the design specification of a millimeter wave moisture sounder is described. The algorithm is capable of treating the response of a multifrequency radiometer to realistic variations in vertical profiles of atmospheric temperature and moisture, surface emissivity, cloud and precipitation. Analyses were performed to investigate the sensitivity of proposed moisture sounder channels to changes in the vertical distribution of atmospheric water vapor and the presence of cloud and rain. Preliminary studies based on statistical inversion methods demonstrate moisture retrieval capabilities in clear, cloudy, and precipitating cases. Results indicate that cloud and precipitation will most likely degrade moisture sounder performance. Investigation of moisture retrieval methodologies which explicitly treat cloud effects is recommended. Keywords: Atmospheric precipitation; Satellite meteorology; Computer codes; Multiple scattering; Radiative transfer; Clouds.