Open AccessUnderstanding three‐dimensional effects in polarized observations with the ground‐based ADMIRARI radiometer during the CHUVA campaign
Author(s) -
Battaglia Alessandro,
Saavedra Pablo,
Morales Carlos Augusto,
Simmer Clemens
Publication year - 2011
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jd015335
Subject(s) - radiometer , radiative transfer , remote sensing , brightness temperature , microwave radiometer , atmospheric radiative transfer codes , environmental science , microwave , physics , brightness , meteorology , optics , geology , quantum mechanics
Measurements of down‐welling microwave radiation from raining clouds performed with the Advanced Microwave Radiometer for Rain Identification (ADMIRARI) radiometer at 10.7–21–36.5 GHz during the Global Precipitation Measurement Ground Validation “Cloud processes of the main precipitation systems in Brazil: A contribution to cloud resolving modeling and to the Global Precipitation Measurement” (CHUVA) campaign held in Brazil in March 2010 represent a unique test bed for understanding three‐dimensional (3D) effects in microwave radiative transfer processes. While the necessity of accounting for geometric effects is trivial given the slant observation geometry (ADMIRARI was pointing at a fixed 30° elevation angle), the polarization signal (i.e., the difference between the vertical and horizontal brightness temperatures) shows ubiquitousness of positive values both at 21.0 and 36.5 GHz in coincidence with high brightness temperatures. This signature is a genuine and unique microwave signature of radiation side leakage which cannot be explained in a 1D radiative transfer frame but necessitates the inclusion of three‐dimensional scattering effects. We demonstrate these effects and interdependencies by analyzing two campaign case studies and by exploiting a sophisticated 3D radiative transfer suited for dichroic media like precipitating clouds.