Collaborative Research: Towards Further Understanding of Aerosol Pollution Impacts on Tropical Cyclones

各种各样的人类活动导致不同类型的颗粒进入大气。这些粒子，在大气科学界被称为气溶胶，已经被证明会影响云和降水。该项目将研究三种不同的热带气旋，以确定气溶胶是否会影响这些风暴的减弱或增强，以及它是否取决于气溶胶与风暴相互作用的时间和地点。这项研究很重要，因为它将有助于确定气溶胶对热带气旋的影响是否应该作为改善天气和气候模型的优先投资领域。该项目还将通过将一名研究生纳入研究，为培养下一代科学家作出贡献。研究人员计划研究污染气溶胶对热带气旋强度的影响。先前的观测和模拟研究对这些气溶胶是减弱还是加强风暴得出了不同的结论。研究人员假设，一个关键因素是在风暴中引入增强气溶胶的位置。计划中的工作将包括将GEOS-Chem大气化学模型与海洋-陆地-大气模型（OLAM）结合起来，并对三个观测良好的风暴进行大量模拟：西太平洋台风努里（2008年）、飓风桑迪（2012年）和飓风温贝托（2007年）。该提案的主要假设是：1)成熟热带气旋对人为气溶胶的响应取决于热带气旋内气溶胶的分布，更多的气溶胶进入风暴的外雨带区，导致风暴减弱，而更多的气溶胶进入眼壁和内雨带区，导致风暴增强。2)热带扰动或热带风暴中吸收的人为气溶胶有可能导致风暴增强。3)进入正在向冷核系统过渡的热带气旋的污染气溶胶不太可能对风暴强度的变化作出实质性贡献，但可能有助于增强降雨。

A variety of human activities result in the transportation of different types of particles into the atmosphere. These particles, known as aerosols in the atmospheric science community, have been shown to impact clouds and precipitation. This project will study three different tropical cyclones to determine whether aerosols affect the weakening or strengthening of these storms, and whether it depends on when and where the aerosols interact with the storm. The research is important because it will help to determine whether aerosol impacts on tropical cyclones should be included as a priority investment area for improving weather and climate models. The project will also contribute to the training of the next generation of scientists through the inclusion of a graduate student in the research.The researchers plan to address the impact of pollution aerosols on tropical cyclone intensity. Prior observational and modeling studies have come to differing conclusions on whether these aerosols weaken or strengthen a storm. The researchers hypothesize that a key factor is the location in the storm where the enhanced aerosols are introduced. The planned work will consist of joining the GEOS-Chem atmospheric chemistry model to the Ocean-Land-Atmosphere Model (OLAM) and performing a number of simulations on three well-observed storms: western Pacific typhoon Nuri (2008), hurricane Sandy (2012), and hurricane Humberto (2007). The main hypotheses of the proposal are: 1) The response of a mature tropical cyclone to anthropogenic aerosols depends on the distribution of aerosols within the tropical cyclone with more aerosols entering the outer rainband region of the storm contributing to storm weakening whereas more aerosols entering the eyewall and inner rainband region contributing to storm intensification, 2) Anthropogenic aerosols ingested in a tropical disturbance, or a tropical storm, have the potential to contribute to the intensification of a storm, perhaps leading to the formation of a tropical cyclone, 3) Pollution aerosols entering a tropical cyclone undergoing transition to a cold-core system are unlikely to contribute substantially to storm intensity change, but are likely to contribute to enhanced rainfall.