CAESAR: Characterization of Boundary-Layer Convective Precipitation in Arctic Cold Air Outbreaks

CAESAR：北极冷空气爆发时边界层对流降水的特征

• 批准号: 2317116
• 负责人: Yonggang Wang
• 金额: $ 23.4万
• 依托单位: SUNY College at Oswego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317116&HistoricalAwards=false
• 关键词: CAESAR; Characterization; Boundary; Layer; Convective

Arctic climate is changing at a faster pace than anywhere on Earth. Climate projections indicate that the Arctic will continue to warm, but uncertainties arise due to questions about the future behavior of Arctic clouds. An area of primary uncertainty is the properties of clouds that form during cold-air outbreaks, where very cold airmasses over the Arctic ice move southward over the relatively warm open ocean. This award will help to analyze observational data of these clouds (and precipitation) and the exchange of energy between the ocean and atmosphere during the Cold-Air outbreak Experiment in the Sub-Arctic Region (CAESAR), which will be conducted in Spring 2024 out of northern Scandinavia. The observations collected during CAESAR will be used to better understand the characteristics of the cold-air outbreak system, and the Arctic climate system more broadly, to inform climate models and projections. The project will also help to improve forecasting of weather hazards with significant relevance to naval operations, commercial shipping, and coastal communities. The broader field effort includes significant opportunities for students and early-career scientists, international collaboration, and public outreach. This award will provide opportunities for undergraduate students to be involved in the project. Additionally, materials will be adapted for classroom activities and public outreach activities are planned.The focus of this individual project is on the shallow precipitation systems that form during Arctic cold air outbreaks (CAOs). The researcher will use data collected during CAESAR to document the characteristics of boundary-layer convective (BLC) precipitation. BLC precipitation in the Arctic is inadequately documented and characterized, and poorly predicted. The primary objectives of the project are to document the vertical structure of BLC precipitation systems and to explore the role of BLC precipitation on transitions in mesoscale organization. A large subset of CAESAR observational data will be used alongside high-resolution mesoscale modeling. Specifically, the project tasks are to: 1) Conduct a CAO case study to characterize BLC cloud and precipitation systems, 2) Conduct a composite study to describe the diversity of BLC clouds and precipitation, 3) Perform non-Large Eddy Simulation (LES) runs for selected CAO cases, 4) Perform LES simulations and sensitivity studies to test the hypotheses.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.

北极气候的变化比地球上任何地方都要快。 气候预测表明，北极将继续温暖，但由于对北极云的未来行为的疑问，出现了不确定性。 主要不确定性的区域是在冷空气中爆发过程中形成的云的特性，北极冰上的非常冷的气动在相对温暖的开阔海洋上向南移动。 该奖项将有助于分析这些云（以及降水）的观察数据，以及在北极地区（凯撒）冷空气爆发实验期间海洋和大气之间的能量交换，这将于2024年春季进行。北斯堪的纳维亚半岛。 凯撒期间收集的观察结果将用于更好地了解冷空气爆发系统的特征，以及更广泛的北极气候系统，以告知气候模型和预测。 该项目还将有助于改善与海军行动，商业航运和沿海社区的重要相关性的天气危害的预测。 更广泛的现场努力包括学生和早期职业科学家，国际合作和公共宣传的重要机会。 该奖项将为本科生参与该项目提供机会。 此外，还计划将材料改编成课堂活动和公共外展活动。该单独的项目的重点是在北极冷空气爆发期间形成的浅降水系统（CAOS）。 研究人员将使用凯撒期间收集的数据来记录边界对流（BLC）降水的特征。 北极中的BLC降水量不充分，表征和预测较差。 该项目的主要目标是记录BLC降水系统的垂直结构，并探讨BLC降水在中尺度组织中的过渡中的作用。 大量的凯撒观测数据将与高分辨率的中尺度建模一起使用。 具体而言，项目任务是：1）进行CAO案例研究以表征BLC云和降水系统，2）进行复合研究以描述BLC云和降水的多样性，3）进行非大型涡流模拟（LES）对于选定的CAO病例，4）进行LES模拟和灵敏度研究以检验假设。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来获得支持。