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

大气气溶胶，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产生深远影响。由于对复杂的气溶胶特性、气溶胶-云相互作用以及气溶胶在空间和时间上的变化缺乏了解，气候评估和预测中存在很大的不确定性。该项目旨在研究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特性。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。该研究项目将提供机会，通过让代表性不足的少数民族学生参与研究，并将研究结果纳入加州大学洛杉矶分校和加州理工学院的课堂，将研究与教育结合起来。该研究的总体目标是描述各种类型气溶胶的垂直分布特征，并研究其对对流云的影响，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建模，关键的科学问题是：（1）不同气溶胶类型的垂直分布的具体特征及其季节和区域变化是什么？(2)各种气溶胶类型的垂直分布如何影响对流云的微观和宏观物理特性以及相关的降水？为了回答这些问题，将进行三项具体任务：（1）检查不同地区和季节各种气溶胶类型垂直分布的具体和独特特征;（2）调查各种气溶胶类型垂直分布与对流云和相关降水之间的关系;（3）解开不同气溶胶效应（即，微物理效应和辐射效应）以及气象影响，并使用过程水平模式评估气溶胶垂直分布对对流云和降水在季节时间尺度上的影响。观测分析的结果将用于评估和约束模型模拟，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NSF的法定使命，并被认为值得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。

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.