Modulation of High-Latitude Tropical Cyclone Recurvature by Solar Radiation

Abstract

In this study, idealized simulations are conducted to investigate potential influences of solar radiation on the tropical cyclone (TC) recurvature at higher latitudes. Results indicate that TC track is sensitive to the seasonal variation of radiative forcing at higher latitudes. In the absence of a background flow, TCs at higher latitudes tend to recurve (remain northwestward) in the cold (warm) season. This feature is an additional aspect of the so-called intrinsic recurvature property of TC movement at high latitude. Physically, the greater meridional gradient of temperature in the cold season due to solar radiative forcing would induce a larger thermal wind, which affects the upper-level anticyclonic circulation and associated outflow. The structure changes of TC, mainly at upper-levels, modulate the steering flow for TC, leading to a higher probability of TCs at higher latitudes to recurve in the cold season than in the warm season.