Comparison of satellite-derived MSU brightness temperatures and conventionally-derived fields

Abstract

A statistical analysis is performed on a six-month global data set consisting of satellite-derived channel 3 Microwave Sounding Unit (MSU) brightness-temperatures from the Marshall Space Flight Center and various conventionally-derived fields obtained from the National Meteorological Center Global Data Assimilation System (GDAS) to quantify the potential usefulness of MSU analyses in the nowcasting and forecasting of baroclinic waves especially over data sparse regions. High positive spatial and temporal correlations are obtained between the MSU and the 400-100 mb thickness over all wavelengths in the data. Slightly lesser positive correlations are found between the MSU and the 200-mb temperature. The MSU-500-mb and MSU-50-mb height correlations indicate a scale dependence in the hydrostatic spreading of thickness anomalies in the vertical. Most significantly, relatively high negative MSU-500-mb height correlations for the short (less than synoptic scale) wavelength portion of the data suggest that upper-level thermal anomalies are reflected downwards and that the MSU can be used to track mid-level synoptic-scale baroclinic waves. This conclusion is also suggested in MSU-500-mb vorticity and MSU-dynamic tropopause correlations. A MSU collection and analysis procedure is also described that demonstrates the practicality and usefulness of generating MSU analyses from locally obtained polar-orbiter data.