Rain retrieval algorithms from satellite-borne microwave radiometers (MWR) utilize lookup tables (LUTs) related between MWR brightness temperatures (Tbs) and rain intensity and databases about precipitation characteristics. Since LUT is generated to simulate Tbs from vertical rain profiles through a radiative transfer model, the accuracy of estimation in precipitation amount depends on the input vertical rain profiles. Some previous studies reported that underestimation of precipitation occurred for generated or reinforced rain systems by orography and over high elevation area. In order to improve the underestimation, orographic precipitation identification was applied to the Global Satellite Mapping of Precipitation (GSMaP) algorithm. Upward wind by topography and moisture convergence at near the surface calculated by a re-analysis data and a digital elevation map were utilized to identify areas in orographic precipitation, and a new LUT based on a warm rain case was constructed and applied to the GSMaP algorithm. In addition to the case, we examined representative vertical profiles in precipitation for above mentioned precipitation characteristics. Compared to the standard GSMaP product, clear improvement can be found for a orographic precipitation case affected by a typhoon in Taiwan.

Date Published: 8 November 2012
PDF: 6 pages
Proc. SPIE 8523, Remote Sensing of the Atmosphere, Clouds, and Precipitation IV, 85230B (8 November 2012); doi: 10.1117/12.977280

Published in SPIE Proceedings Vol. 8523:
Remote Sensing of the Atmosphere, Clouds, and Precipitation IV
Tadahiro Hayasaka; Kenji Nakamura; Eastwood Im, Editor(s)