On the relationship between tropical cyclone intensity and characteristics of the tropopause in the North Atlantic based on COSMIC-2 observations

This study investigates the mutual connections between tropical cyclone (TC) intensification and tropopause characteristics during TCs using high-resolution GPS radio occultation observations from 2020 to 2025 from the Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) in the North Atlantic basin. The mean tropopause height and temperature show no discernible difference across different TC intensity bins. In contrast, the convective outflow height (COH) demonstrates a remarkable increase with TC intensity. The composite analysis identifies distinct thermodynamic signatures in the TC inner-core region, characterized by elevated COH. The correlation of COH with TC intensity is significant during the rapid intensification (RI) and weakening stages; and the lead–lag correlation between COH and TC intensity during the RI stage reveals that COH precedes the changes in TC intensity during RI events. The results suggest that monitoring tropopause characteristics could provide valuable indicators for forecasting TC intensity changes. 本研究利用2020年至2025年COSMIC-2在北太平洋的高分辨率GPS无线电掩星观测资料, 探讨了对流层顶特征与热带气旋强度和强度变化之间的联系.研究发现, 对流层顶平均高度和温度在不同热带气旋强度区间未表现出显著差异;相比之下, 对流出流层高度则随热带气旋强度增强呈现明显上升趋势.合成分析表明, 在热带气旋内核区域对流出流层高度会显著高于环境场.在热带气旋快速增强与减弱阶段, 对流出流层高度与热带气旋强度呈显著相关性.通过对流出流层高度与热带气旋强度的超前-滞后相关分析显示, 在热带气旋快速增强阶段, 对流出流层高度的变化早于热带气旋强度的变化.以上结果表明, 监测对流层顶特征将有助于预测热带气旋强度变化.