Status of Global High Resolution Precipitation Estimation from Remotely Sensed Information

Featuring Ali Behrangi, Ph.D.
NASA Jet Propulsion Laboratory
California Institute of Technology

Location:  Engineering Hall 2430 Colloquia Room
Free and open to the public

Abstract:
The rising popularity of distributed hydrologic modeling and recent enhancements of atmospheric models’ resolution have contributed to the increasing demands for accurate and consistent high resolution precipitation data. At global scale, insufficient ground observations have made satellite-based precipitation estimates the only available source for wide coverage data. Clearly, continuing improvement of satellite estimates of the amount, spatial, and temporal distribution of precipitation is a vital to a wide range of applications at different scales ranging from global-climate modeling down to local-weather, flashflood prediction. Combining more accurate passive microwave (PMW) and more frequent infrared (IR) estimates of precipitation is an active area of research in satellite precipitation retrieval. The anticipated launching of NASA’s GPM and the increasing number of spectral bands in recent and near future  Geostationary platforms (e.g., SEVIRI on MSG and ABI on GOES-R) will provide greater opportunities for investigating new approaches to combine multi-source information towards improved consistency, accuracy, coverage, and timeliness of high resolution precipitation. In this talk a brief review of current precipitation estimation products will be provided. In a comparative frame work and through a pixel-/cloud-patch based approach the role of multi-spectral data for rain area delineation and rain rate estimation is discussed. In continue a method for rain estimation using forward Adjusted-advection of PMW rain estimates is proposed. The method uses a cloud tracking algorithm and allows for real time integration of the more accurate precipitation estimates, obtained from PMW sensors, into the short-term cloud evolution process, which can be inferred from frequent geostationary images. Finally, hydrologic and environmental applications of satellite based precipitation estimation will be discussed.

About the Speaker:
Ali Behrangi received B.S. and M.S. degrees in civil and environmental engineering from Sharif University of Technology in Iran. He received his doctoral degree from the University of California, Irvine, in 2009, under the advisement of Soroosh Sorooshian, Ph.D., distinguished professor of civil and environmental engineering and Earth system science and director of the Center for Hydrometeorology and Remote Sensing. He is currently a Caltech postdoctoral scholar at NASA JPL. His research interests include the development of satellite-based multi-sensor/ multi-spectral precipitation estimation algorithms particularly for hydrologic applications that require high time and space resolution. Behrangi is the recipient of several awards, including the NASA Earth and Space Science Fellowship (NESSF, 2008-2009).