577A The Signal of Future Tropical Cyclone Intensification in the CloudSat Measurements

Tuesday, 24 January 2017
4E (Washington State Convention Center )
Shun-Nan Wu, Univ. of Miami, Miami, FL; and B. J. Soden

Handout (6.5 MB)

This study examines how the vertical stricture of convective heating influences the evolution of tropical cyclone (TC) intensity using CloudSat Tropical Cyclone (CSTC) dataset. Both theoretical and modeling studies demonstrate that the location of convective heating can play an important role in modulating changes in TC intensity. However, observations of vertical profiles of convective heating are limited. Fortunately, CloudSat measurements profile high-resolution observations of cloud ice and liquid water content that can serve as useful proxies for convective heating. To determine if there are observable signals of future TC intensity change, we construct composites of CloudSat profile for strengthening and weakening TCs. While the difference in total rain rate between strengthening and weakening TCs is small, we find a significant difference in cloud water content between the two composites. In particular, strengthening TCs have higher ice water content than weakening TCs, especially between 6-10 km in vertical and within a 2 km radius of the maximum wind.  This analysis provides observational evidence that even though the total convective heating rates are similar in both strengthening and weakening storms, different locations of convective heating alter the evolution of TC intensity.  Further investigation into the signal in different categories of TC intensity and the time scale of the relation between amount of ice water content and storm intensity will be presented at the conference.
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