Spatial Variability of Dropsonde‐Derived Moist Static Energy in North Atlantic Tropical Cyclones

Abstract

The spatial variability of moist static energy (MSE) and its column‐integral (CMSE) around tropical cyclones (TCs) are known to help prognose TC development. Though limited in number and spatial coverage per TC, modeling work suggests that dropsondes, when strategically deployed, can reliably capture radial MSE and CMSE variability. This study uses North Atlantic upper‐level reconnaissance dropsondes from 1996 to 2021 to produce the most extensive observational analysis of MSE structure in TCs to date. MSE and CMSE decrease with distance from the TC center. MSE spatial variability is larger in Category 1 and 2 hurricanes compared to tropical storms, and generally largest after a TC's lifetime maximum intensity. Moisture dominates the MSE spatial variability but temperature contributes in the upper levels near the TC center. While differences in MSE spatial variability between weakening and intensifying TCs are less clear, raw MSE tends to be greater in intensifying TCs at most radii and vertical levels.