The thermodynamic state of the tropical atmosphere plays an important role in the development of tropical cyclone(TC)intensity.This study reports new results that demonstrate a negative association between eastern Pac...The thermodynamic state of the tropical atmosphere plays an important role in the development of tropical cyclone(TC)intensity.This study reports new results that demonstrate a negative association between eastern Pacific TC intensity in offshore regions and dust aerosol optical depth(AOD)for the years 1980–2019.At the same time,a negative response of cloud water in the lower troposphere to dust AOD is reported by analyzing MERRA-2 reanalysis data and GCM simulations from CMIP6.This response can be explained by the dust semi-direct effect,in which dust aerosols absorb solar radiation,promoting the evaporation of clouds.In principle,this aerosol-driven vaporization modification could affect the enthalpy of the air surrounding a TC.Using potential intensity theory,the authors demonstrate that change in TC intensity related to dust AOD conditions is a consequence of the anomalous enthalpy of the air surrounding a TC caused by the dust semi-direct effect.展开更多
基金This work was supported by National Natural Science Foundation of China[grant numbers 41675062 and 41375096]the Research Grants Council of the Hong Kong Special Administrative Region,China[project numbers CityU 11306417 and 11335316].
文摘The thermodynamic state of the tropical atmosphere plays an important role in the development of tropical cyclone(TC)intensity.This study reports new results that demonstrate a negative association between eastern Pacific TC intensity in offshore regions and dust aerosol optical depth(AOD)for the years 1980–2019.At the same time,a negative response of cloud water in the lower troposphere to dust AOD is reported by analyzing MERRA-2 reanalysis data and GCM simulations from CMIP6.This response can be explained by the dust semi-direct effect,in which dust aerosols absorb solar radiation,promoting the evaporation of clouds.In principle,this aerosol-driven vaporization modification could affect the enthalpy of the air surrounding a TC.Using potential intensity theory,the authors demonstrate that change in TC intensity related to dust AOD conditions is a consequence of the anomalous enthalpy of the air surrounding a TC caused by the dust semi-direct effect.
