Impact of Surface-Cloud Coupling on Aerosol-Radiation- Cloud-Interactions for Boundary-layer Clouds over Land and Oceans

该项目寻求资金，以调查从地球表面加热的影响，在运输微小颗粒（也称为气溶胶）和水蒸气在大气中向上形成云和降水，以及气溶胶和云如何影响表面加热通过阻挡阳光或表面冷却通过阻止表面热量释放-这个过程被称为辐射。气溶胶主要存在于距地球表面约1英里的大气层中，也称为行星边界层（PBL）。PBL的气象和大气环境对我们的生活至关重要。气溶胶/云与地球表面之间的相互作用是天气预报和气候研究中最不确定的因素之一。该项目旨在提高对陆地和海洋相互作用的一些基本过程的理解。通过在地面-云耦合的背景下研究边界层云和气溶胶输送的发展，该项目将有助于促进我们对极端天气，气候变化和空气污染的理解，这些都对社会至关重要。该研究项目将培养年轻科学家成为下一代科学家和教育家，以了解和解决天气预报面临的问题。拟议研究的首要问题是气溶胶-辐射相互作用（ARI）和气溶胶-云相互作用（ACI）如何受到云与地面或大陆云和海洋云的PBL之间的耦合的影响。由于云和地面之间的耦合预计将在调节ARI和ACI方面发挥重要作用，因此该项目将整理出由云-PBL-地面耦合决定的边界层过程。本研究将检验以下假设：（1）吸收性气溶胶抑制边界层的热通量和卷吸过程，抑制对流的发生和大陆积云的发展;（2）在解耦条件下，到达海洋云层的地面云凝结核比例较低，导致ACI明显减弱，对降水的影响减弱，而耦合条件的情况则相反。利用综合的实地观测，本项目将研究ARI和ACI对不同地面-云耦合状态下热通量垂直分布、卷吸和对流启动的影响。该项目还将探索云与地面之间的解耦如何调节气溶胶垂直传输，以及云的微观和宏观物理特性如何对耦合状态做出响应。这些任务还将有助于量化ACI和ARI的单独和联合影响的程度。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来支持。

The project seeks funding to investigate impacts of heating from the earth’s surface in transporting tiny particles (also called aerosols) and water vapor in the atmosphere upward to form clouds and precipitation as well as how aerosols and clouds affect the surface heating by blocking sunlight or the surface cooling by blocking the surface heat release---the process is called radiation. Aerosols are found mostly in the air layer of about 1 mile above the earth surface, which is also called the planetary boundary layer (PBL). Meteorology and the atmospheric environment in the PBL are of utmost importance to our lives. Interactions between aerosols/clouds and the earth’s surface are among the most uncertain factors in weather forecasting and climate studies. This project aims to improve understanding of some fundamental processes governing the interactions over both land and oceans. By examining the development of boundary-layer clouds and aerosol transport in the context of the surface-cloud coupling, this project will help advance our understanding of extreme weather, climate change, and air pollution, which are critical to the society. The research project will train young scientists to become the future generation of scientists and educators to understand and resolve problems facing weather forecasts.The overarching question of the proposed study is how aerosol-radiation interactions (ARI) and aerosol-cloud interactions (ACI) are affected by the coupling between clouds and the surface or the PBL for both continental and marine clouds. Because the coupling between clouds and the surface is expected to play an important role in regulating ARI and ACI, the project will sort out the boundary-layer processes dictated by the cloud-PBL-surface coupling. The study will test the hypotheses: (1) absorbing aerosols inhibit heat fluxes and the entrainment process of the PBL, suppressing convection initiation, and the development of continental cumulus clouds; (2) the fraction of surface cloud condensation nuclei reaching the marine cloud layer is lower under the decoupled condition, leading to markedly weaker ACI with weakened impacts on precipitation, whereas the opposite is the case for the coupled condition. Using comprehensive field observations, this project will investigate the impacts of ARI and ACI on the vertical distribution of heat fluxes, entrainment, and convection initiation for different surface-cloud coupling states. The project will also explore how the decoupling between clouds and the surface regulates aerosol vertical transport and how cloud micro- and macro-physical properties respond to the coupling state. These tasks will also help quantify the magnitudes of both individual and joint effects of ACI and ARI.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.