The Dependence of Moist Vortex Intensification on Convection‐Induced Moisture Distribution and Low‐Level Inflow: Insights for Tropical Cyclone Seed Genesis

Abstract This study proposes a novel idealized experimental design to investigate the process by which convection clusters transition into tropical cyclone seeds (TC seeds), with a particular focus on the role of convection‐induced transverse circulation in the radial–vertical plane. We use cloud‐resolving simulations of convection self‐aggregation to represent various initial states of convective cloud clusters, ranging from scattered to aggregated to systematically quantify the dependence of moist vortex intensification to the coupled structure of moisture, convection, and circulation. We then introduce a uniform Coriolis force to these initial states to simulate and examine the short‐term variations in vortex intensity under the same background vorticity. The centroid of positive vorticity is used to identify both the convergence center of non‐rotating convection clusters and the cyclonic circulation center of the moist vortex to diagnose axisymmetric differences in water vapor distribution, convective core cloud, and transverse circulation among different convection clusters, which is applicable even for weak vortices. In convective clusters with weak an established transverse circulation, the tangential wind of the vortex remains weak and its structure loose. In contrast, when transverse circulation develops, the moist vortex effectively intensifies within 3 days. Moisture distribution determines the occurrence of the convection core clouds, which contribute to the updraft of the transverse circulation. We identify the non‐linear relationship between daily mean low‐level inflow (>2 m/s) and vortex intensification, which indicates the criticality in TC seed genesis. This can be a useful framework to evaluate moist vortex development in different cloud‐resolving models.