Retrieval of slant water path, liquid water and rain events using the cloudy sky ratio from K-band brightness temperature measurements

Abstract

The Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign was conducted to improve understanding and modeling of the Madden-Julian oscillation (MJO). Observations during DYNAMO focused on atmospheric parameters important for understanding MJO initiation, including vertical moisture profiles, cloud structure, precipitation processes and the planetary boundary layer. These observations were performed using a variety of in-situ and remote sensing instruments, including the S-PolKa radar deployed by the National Center for Atmospheric Research (NCAR) and the collocated University of Miami (UM) microwave radiometer operating at 23.8 and 30.0 GHz. These instruments sampled approximately the same volumes of the atmosphere. A second microwave radiometer was deployed by the Atmospheric Radiation Measurement (ARM) Program approximately 8.5 km from the UM radiometer. These observations provided an opportunity to retrieve slant water path (SWP) and slant liquid water (SLW) from ground-based microwave radiometer measurements over a range of azimuth and elevation angles during both clear sky and cloudy conditions. The retrieved SWP and SLW will be compared to those from S-PolKa radar measurements. The goal of this study is to develop an algorithm to retrieve water vapor and liquid water from ground-based radiometer measurements.