Collaborative Research: A Synergistic Study of Aerosol Vertical Distributions and their Effects on Convective Clouds and Precipitation

大气中的气溶胶，如化石燃料、木材和其他燃料不完全燃烧产生的细颗粒，可以改变云的形成和降水。因此，它们对地球的天气和气候系统有着深远的影响。由于对复杂的气溶胶特性、气溶胶与云的相互作用以及气溶胶在空间和时间上的变化缺乏了解，导致气候评估和预估存在很大的不确定性。该项目旨在调查气溶胶如何垂直变化，以及气溶胶如何影响大面积云的发展和性质。该项目的研究结果有望提高我们对气溶胶-云相互作用的认识，并解决气候变化研究中的不确定性问题。该研究项目将提供整合研究和教育的机会，让代表性不足的少数民族学生参与研究，并将研究成果纳入加州大学洛杉矶分校和加州理工学院的课堂。本研究的总体目标是通过结合基于最先进的卫星数据和现场测量的数据分析，以及气溶胶感知和云分辨WRF模型，来表征各种气溶胶的垂直分布，并研究它们对对流云和降水的影响。关键的科学问题是：(1)不同气溶胶类型垂直分布的具体特征和季节和区域变化是什么？(2)不同气溶胶类型的垂直分布如何影响对流云和降水的微观和宏观物理性质？为了回答这些问题，我们将进行三项具体工作：(1)研究不同地区和季节不同类型气溶胶垂直分布的具体和独特特征；(2)研究不同气溶胶类型的垂直分布与对流云和相关降水的关系；(3)厘清不同气溶胶效应（即微物理效应和辐射效应）和气象影响，并利用过程水平模式在季节时间尺度上评估气溶胶垂直分布对对流云和降水的影响。观测分析的结果将用于评估和约束模式模拟，以减少与气溶胶-云-降水相互作用相关的不确定性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Atmospheric aerosols, such as fine particles from the incomplete combustion of fossil fuels, wood and other fuels, can modify cloud formations and precipitation. Thus, they have profound impacts on the Earth’s weather and climate systems. The lack of understanding of complex aerosol properties, aerosol-cloud interactions, and aerosol variations in space and time contributes to large uncertainties in the climate assessment and projection. The project aims to investigate how aerosols vary vertically and how aerosols influence cloud development and properties over a large area. Findings of this project are expected to advance our knowledge on aerosol-cloud interactions and address uncertainties in climate change studies. This research project will provide opportunities to integrate research and education by involving underrepresented minority students to conduct the research and incorporating the outcomes from this research into classes at University of California at Los Angeles and California Institute of Technology.The overarching objective of this research is to characterize the vertical distributions of various types of aerosols and to study their impacts on convective clouds and precipitation through a combination of data analysis based on state-of-the-art satellite data and in situ measurements, as well as aerosol-aware and cloud-resolving WRF modeling. The key scientific questions are (1) what are the specific characteristics and seasonal and regional variations of the vertical distribution of different aerosol types? (2) how do the vertical distributions of various aerosol types affect the micro- and macro-physical properties of convective clouds and the associated precipitation? Three specific tasks will be performed to answer these questions: (1) to examine the specific and unique characteristics of the vertical distributions of various aerosol types in different regions and seasons; (2) to investigate the relationships between vertical distributions of various aerosol types and convective clouds and associated precipitation; (3) to disentangle different aerosol effects (i.e., microphysical effect and radiative effect) as well as meteorological influence, and assess effects of aerosol vertical distributions on convective clouds and precipitation on the seasonal timescale using process-level models. Results from observational analyses will be used to evaluate and constrain model simulations to reduce the uncertainties associated with aerosol-cloud-precipitation interactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.