Use of Radar Profilers in Multi-Sensor Ground Validation for TRMM and GPM

摘要

Realistic simulation of the hydrologic cycle in global climate models remains a difficult challenge since climate models cannot resolve convective systems. Only satellites can provide global precipitation estimates needed to validate global climate models. The algorithms used to relate precipitation estimates to satellite observables require ground-based observations for development and validation purposes. In this paper we outline how profilers can be used in combination with other ground based instruments to support the retrieval of precipitation estimates from satellites. The profilers provide quantitative information on the vertical structure and temporal variability of reflectivity and precipitation parameters related to drop-size distributions (DSD) that are essential for quantitative precipitation estimation. The profilers are most naturally calibrated by reference to a collocated disdrometer and are in turn useful for providing calibration for scanning radars. The use of profilers for ground validation is illustrated by examples drawn from the Tropical Rainfall Measuring Mission (TRMM) Ground Validation field campaigns and the Global Precipitation (GPM) Front Range Pilot Project conducted in Colorado in 2004.