Comparison of microwave brightness temperatures and radar reflectivity measurements

摘要

Satellite-sensor based microwave brightness temperatures are compared with radar based reflectivities for a 3D raining cloud. The brightness temperatures are computed using a radiative transfer model based on the discrete-ordinates method. The synthetic reflectivities are generated from a 3D physically based radar simulation. Comparisons between the brightness temperature and reflectivity fields at matched resolutions appear to be well correlated and may indicate that reflectivity measurements could be combined with brightness temperature observations in order to estimate rainrates. Results of a simulation examining the relationship between surface rainfall rate, reflectivity, and brightness temperature measurements are reported. The stochastic framework of this study allows the variance of remotely sensed quantities to be described in terms of variations that might occur in realistic precipitation events, and provides a framework for calibrating satellite-based rainfall estimation methods using radar measured reflectivities.