Transient simulation of the spatiotemporal evolution of tropical cyclone genesis potential during the Holocene

Tropical cyclones (TCs) are among the most destructive weather systems, yet their long-term variability under different climate forcings remains poorly constrained due to limited observational records. This study investigates the spatiotemporal evolution of TC genesis (TCG) potential during the Holocene using a transient simulation forced solely by orbital variations. Two widely used genesis potential indices (GPIs) are analyzed to diagnose large-scale environmental conditions favorable for TC formation. Empirical orthogonal function analysis reveals coherent leading modes in both GPIs, characterized by a poleward shift of TCG potential in the Northern Hemisphere and an equatorward shift in the Southern Hemisphere during the early Holocene, followed by a gradual reversal afterwards. These changes closely track orbitally driven seasonal insolation variations. Further analyses show that the evolution of GPIs is governed by thermodynamic and dynamic factors that co-vary in response to orbital forcing through mechanisms such as Intertropical Convergence Zone migration, monsoon strengthening, and changes in meridional temperature gradients. Unlike future greenhouse gas–induced warming, in which thermodynamic and dynamic responses tend to diverge, Holocene orbital forcing induces physically consistent changes in both indices. These findings highlight that orbital-scale variations provide valuable analogs for understanding the large-scale environmental controls on TC activity in a warming climate. 热带气旋是破坏性极强的天气系统, 但其长期变化受限于观测资料而认识不足.基于仅受轨道参数变化驱动的全新世瞬变模拟, 本研究分析了热带气旋生成潜势指数(GPI)的时空演变特征.结果表明, 两种GPI的主模态具有一致变化:全新世北半球GPI逐渐向低纬移动,南半球向赤道外移动, 这与轨道尺度季节性太阳辐射变化密切相关.热力和动力因子在轨道强迫下协同演变, 通过ITCZ迁移,季风增强和经向温度梯度变化共同调制热带气旋生成环境.