Investigating the Evolution of TC Precipitation Structure and Storm Intensification in Relation to Environmental Humidity Fields

Tropical cyclone (TC) is one of the biggest threats to life and property around the world, which causes many life-threatening natural hazards, including storm surge, flooding, extreme winds, tornadoes and lighting. While the forecast of TC tracks has been significantly improved in the past several decades, the TC intensity forecast is still a great challenge for most operational numerical weather prediction centers. Environmental humidity has long been considered as an important factor affecting TC’s intensification process. Composite studies using analyses data sets and satellite observations have shown that rapid intensification (RI) of TCs is associated with higher environmental RH in the lower and middle troposphere than non-RI events. Although these previous studies highlighted the importance of the dry air intrusion in the hurricane development process, it remains unclear “whether the dry air acts to potentially weaken TCs through modification of precipitation structure or overall convective activity” (Braun et al., 2012). NASA’s Time-Resolved Observations of Precipitation Structure and Storm Intensity with a Constellation of Smallsats (TROPICS) mission provides both the precipitation and relative humidity measurements via the TROPICS Microwave Sounder (TMS) observations. We plan to use the TROPICS constellation observations to disentangle the dry air intrusion’s influence on the TC’s precipitation structure variation and convective activity evolution over the lifetime of storms.