Moisture control of tropical cyclones in high-resolution simulations of paleoclimate and future climate

Abstract

Abstract The intensity of tropical cyclones (TCs) is expected to increase in response to greenhouse warming. However, how future climate change will affect TC frequencies and tracks is still under debate. To further elucidate the underlying sensitivities, we study TCs response to different past and future climate forcings. Using a high-resolution TC-resolving global Earth system model with 1/4o atmosphere and 1/10o ocean resolution we conducted a series of paleo-snapshot and future greenhouse warming simulations targeting the last interglacial (Marine Isotope Stage (MIS) 5e, 125 ka), glacial sub-stage MIS5d (115 ka), present-day (PD), and CO2 doubling (2×CO2) conditions. Our analysis reveals that precessional forcing creates an interhemispheric difference in simulated TC densities, whereas future CO2 forcing impacts both hemispheres in the same direction. In both cases, we find that TC genesis frequency, density, and intensity are primarily controlled by changes in tropospheric thermal and moisture structure, with warmer hemispheres exhibiting a reduction in TC density. Teaser Precessional and CO2 effects on tropical cyclone formation are primarily controlled by moisture-related processes.