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Rain drop size distribution variability and impact on X‐band polarimetric radar retrieval: Results from the AMMA campaign in Benin
Author(s) -
Gosset Marielle,
Zahiri EricPascal,
Moumouni Sounmaila
Publication year - 2010
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.556
Subject(s) - disdrometer , polarimetry , rain gauge , environmental science , radar , meteorology , attenuation , remote sensing , storm , rain rate , weather radar , monsoon , geography , precipitation , computer science , physics , scattering , telecommunications , optics
During the African Monsoon Multidisciplinary Analysis (AMMA) field campaign, polarimetric weather radars, a rain‐gauge network and disdrometers were available to analyse the convective systems and the rainfall in Benin. In this paper a three‐year dataset of drop size distributions is used to compute theoretical relationships between X‐band polarimetric variables and the rain rate, adjusted for the region of interest. The variability of these relationships from storm to storm and between rain types is studied. With an X‐band polarimetric radar the rain rate can be retrieved from the differential specific phase shift K DP , the specific attenuation A H , the reflectivity Z or differential reflectivity Z DR corrected for attenuation, or a combination of these variables. The set of coefficients needed to run the rain retrieval or the attenuation correction schemes under the conditions found in Benin are computed. The rain retrieval schemes are compared on the basis of simulations. The retrievals based on one single propagative variable like K DP or A H perform well. Preliminary results from direct comparisons between X‐band polarimetric radar estimates and rain‐gauges are consistent with the disdrometer‐based analysis. Copyright © 2010 Royal Meteorological Society