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，以调查来自地球表面的加热在向上输送微小颗粒(也称为气溶胶)和大气中的水蒸气以形成云和降水的影响，以及气溶胶和云如何通过阻挡阳光来影响表面加热或通过阻止表面热释放来影响表面冷却-这个过程被称为辐射。气溶胶主要存在于地球表面上方约1英里的空气层中，也被称为行星边界层(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。该项目旨在增进对管理陆地和海洋相互作用的一些基本过程的了解。通过研究地面-云耦合背景下边界层云和气溶胶输送的发展，这个项目将有助于增进我们对极端天气、气候变化和空气污染的理解，这些对社会来说是至关重要的。该研究项目将培养年轻科学家成为未来一代的科学家和教育工作者，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，该项目将对云-PBL-地面耦合所决定的边界层过程进行分类。研究将检验假设：(1)吸收气溶胶抑制热通量和PBL的夹带过程，抑制对流的启动和大陆积云的发展；(2)在解耦条件下，地面云凝结核到达海洋云层的比例较低，导致ACI明显减弱，对降水的影响减弱，而耦合条件则相反。利用综合的野外观测，本项目将研究ARI和ACI对不同地云耦合状态下热通量的垂直分布、夹带和对流启动的影响。该项目还将探讨云和地面之间的脱钩如何调节气溶胶垂直输送，以及云的微观和宏观物理性质如何对耦合状态作出反应。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。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.