Examining tropical cyclone thermodynamic structure with TROPICS observations

Abstract This study examines the three-dimensional thermodynamic structure of a rapidly intensifying tropical cyclone (TC) through the utilization of synthetic retrievals based off of the specifications of NASA’s Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission. Proxy TROPICS vertical profiles of temperature and water vapor mixing ratio generated from the Hurricane Nature Run (HNR1; Nolan et al. 2013) are utilized to analyze the TC structure over a 10-day period that includes the HNR1 TC’s rapid intensification (RI) from a tropical storm to a major hurricane. Analyses are performed to assess how accurately TROPICS may be able to determine thermodynamic profiles both within the storm and in the environment by validating against the HNR1 model data. It is found that the TROPICS retrievals compare favorably with the HNR1 data at most heights and times with errors consistently less than the proposed mission requirements (2 K for temperature; 25% for humidity). In addition, the retrievals show the ability to qualitatively track extensive dry air that is present in the vicinity of the TC. Although a substantial dry bias is present within the storm region of the TC (between 0 – 200 km from the surface center) in the 350–550 mb layer in the TROPICS retrievals, this bias is reduced when the retrievals associated with precipitating grid points are removed from the analyses. However, despite this filtering, a significant bias remains, which suggests that the TROPICS retrievals will likely lose accuracy in regions of stronger scattering.