6.1
Global distribution of extremely intense storms between 36 S and 36 N using evidence from the TRMM radar
David P. Yorty, University of Utah, Salt Lake City, UT; and E. J. Zipser and S. W. Nesbitt
The Precipitation Radar (PR) on the Tropical Rain Measuring Mission (TRMM) satellite has been operating successfully for more than 3 years, sampling all locations between 36 S and 36 N. Many of these regions are remote or inaccessible, for which the TRMM PR has provided the first opportunity to describe storms, and compare their structure quantitatively with those elsewhere. We have assembled a database of more than 4 million precipitation features defined by the PR, ranging from dimensions of a few km to hundreds of km. For each feature, we have catalogued the highest equivalent reflectivity factor near the surface, and at various heights, as well as the heights reached by the 20, 30, and 40 dBZe contours. Using these statistics as proxies for convective intensity, loosely related to size and vertical speed of the updraft, we are in a position to ask where the most intense storms on earth are found. With some interesting exceptions, the locations are consistent with those found using ice scattering signatures or lightning flash rates as proxies. In near-equatorial latitudes, Africa has a higher frequency of intense storms than South America or the "Maritime Continent". Intense storms over oceans are rare except near mid-latitude continents. Some desert regions have surprisingly high incidence of intense storms. The highest concentrations of intense storms are found in mid-latitude continents near or downwind of mountain ranges, but not over high terrain itself.
Session 6, Tropical Rainfall Measuring Mission (TRMM)
Saturday, 21 July 2001, 8:30 AM-12:30 PM
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