Millimeter-wave measurement of frozen hydrometeors during the 2003 Wakasa bay field experiment

Snowfall is an important component of the Earth´s precipitation and hydrological cycle. Remote measurements of frozen hydrometeor properties have been limited because coincident measurements of microphysical and electromagnetic properties of snowfall have not been available. Snowfall measurement from space has been suggested as a solution to overcome this limitation. The precipitating clouds contain a sufficient density of ice water equivalent from snow crystals, graupel, or both, when brightness temperature is at 85 GHz. The NOAA Advanced Microwave Sounding Unit (AMSU) has been used to derive snowfall over land using millimeter-wave radiometry. This study analyzes the millimeter-wave radiometric measurements of frozen hydrometeors during the field experiment that was held in Wakasa bay of Japan in January 29, 2003. It was found that a lognormal distribution represents the snow PSD during the field experiments. The MM5 cloud simulation is employed to provide temperature and humidity profiles for the radiative transfer calculations. This study seeks to derive characteristics of snow whose electromagnetic properties are consistent with microwave brightness temperature at several frequencies provided by the MIR sensors and the radar reflectivity measured by PR-2 (Precipitation Radar) and ACR (Airborne Cloud Radar).