A51P-0302
Impacts of Evaporation of Rainwater on Tropical Cyclone Structure and Intensity
Friday, 18 December 2015
Poster Hall (Moscone South)
Qingqing Li, NUIST Nanjing University of Information Science and Technology, Nanjing, China, Yuqing Wang, University of Hawaii at Manoa, International Pacific Research Center and Department of Meteorology, School of Ocean and Earth Science and Technology, Honolulu, HI, United States and Yihong Duan, CAMS Chinese Academy of Meteorological Sciences, Beijing, China
Abstract:
The impact of evaporation of rainwater on tropical cyclone (TC) intensity and structure is revisited in this study. Evaporative cooling can result in strong downdrafts and produce low–equivalent potential temperature air in the inflow boundary layer, particularly in the region outside the eyewall, significantly suppressing eyewall convection and reducing the final intensity of a TC. Different from earlier findings, results from this study show that outer rainbands still form but are short lived in the absence of evaporation. Evaporation of rainwater is shown to facilitate the formation of outer rainbands indirectly by reducing the cooling due to melting of ice particles outside the inner core, not by the cold-pool dynamics, as previously believed. Only exclusion of evaporation in the eyewall region or the rapid filamentation zone has a very weak effect on the inner-core size change of a TC, whereas how evaporation in the outer core affects the inner-core size depends on how active the inner rainbands are. More (less) active inner rainbands may lead to an increase (a decrease) in the inner-core size.
