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

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. 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. 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. This study first evaluates the precipitation and relative humidity retrieval performance. Our preliminary results show that the hurricane precipitation intensity from TMS is underestimated relative to spaceborne radar estimates, and the precipitation intensity varies among the TROPICS constellation satellites (T01, T03, and T06). Our next step is 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.