摘要：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. 摘要 热带地区大气的热力学状态对台风的发展起着重要作用.本项研究结果表明, 东太平洋台风强度与沙尘AOD之间存在一定的负相关.同时, MERRA-2再分析数据和CMIP6的GCM模拟的分析结果, 都表明了低层大气中云对沙尘AOD的负响应.沙尘颗粒物的准直接辐射效应可以解释上述响应:沙尘颗粒物吸收太阳辐射, 并用此热量促进云层蒸发.理论上, 这种气溶胶驱动的汽化作用会影响台风周围空气的焓.根据台风的潜在强度理论, 与沙尘相关的台风强度变化, 实则是沙尘的准直接辐射效应引起的台风周围空气焓值变化的结果.
