The tropical cyclone wind field and its variability: perspective from the outside in

The low-level wind field in a tropical cyclone is critical both to the energetics of the system as a whole and to the risk posed to life and property by wind, surge, and rain generated by these storms at landfall. Nonetheless, to date most research has focused principally on processes controlling the peak wind speed, with less attention given to wind field size and structure despite their importance in modulating storm impacts. Here we utilize existing theory for the radial structure of absolute angular momentum valid in distinct thermodynamic regimes to develop a novel physical model for the complete radial structure of the tropical cyclone wind field. This simple model is compared to multiple observational databases and shown to be capable of reproducing the characteristic radial structure of the tropical cyclone in nature as well as its dominant modes of space-time variability. The model offers theoretical and conceptual insight into the nature of the tropical cyclone wind field, including the oft-conflated terms “size" and “structure" and their variability.