CAESAR: Characterizing and Understanding Atmospheric Boundary Layer Fluxes, Structure and Cloud Property Evolution in Arctic Cold Air Outbreaks

CAESAR：描述和理解北极冷空气爆发时的大气边界层通量、结构和云特性演化

• 批准号: 2151075
• 负责人: Zhien Wang
• 金额: $ 84.84万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2151075&HistoricalAwards=false
• 关键词: CAESAR; Characterizing; Understanding; Atmospheric; Boundary

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 provide 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 specific project includes a training component for senior level undergraduate students on field methods and observations that will parallel the planning and execution of the CAESAR campaign.This goal of this project is to use multiple remote sensor and in-situ measurements to (1) characterize Marine Boundary Layer (MBL) fluxes, structure and cloud properties and (2) understand the process controlling the evolution of MBL fluxes, structures and cloud properties during cold-air outbreaks (CAOs). The research team will deploy the Multi-function Airborne Raman Lidar (MARLi) and the nadir-only Airborne Doppler Lidar (ADL) to provide profiles of water vapor, temperature, air vertical velocity, and aerosol/cloud structure below the NSF/NCAR C-130 research aircraft to document MBL thermodynamic and dynamic structures, mixing across the MBL top, and cloud phase and property distributions. Analysis of MARLi and ADL data, combined with other observations and modeling during CAESAR, will allow the team to focus on understanding of how upstream boundary layer stratification and wind, MBL rolls and small-scale vertical motions, and surface fluxes and Atmospheric Boundary Layer (ABL) top entrainment/mixing controls MBL development and evolution during CAOs. In addition, these measurements will address the question of how aerosol, MBL processes, and cloud dynamics (stratiform and convective clouds) impact mixed-phase cloud properties, especially liquid-ice mass partitioning.Primary funding for this project comes from the Physical and Dynamic Meteorology program with partial funding from the Arctic Natural Sciences program. The deployment of observational assets for CAESAR is being funded by the Facilities for Atmospheric Research and Education program.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。 该奖项将有助于提供这些云（以及降水）的观察数据，以及在亚北极地区（凯撒）的冷空气爆发实验期间（凯撒）在海洋和大气之间的能量交换，该实验将于2024年春季在斯堪的纳维亚半岛北部进行。 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。 This specific project includes a training component for senior level undergraduate students on field methods and observations that will parallel the planning and execution of the CAESAR campaign.This goal of this project is to use multiple remote sensor and in-situ measurements to (1) characterize Marine Boundary Layer (MBL) fluxes, structure and cloud properties and (2) understand the process controlling the evolution of MBL fluxes, structures and cloud properties during cold-air outbreaks （CAO）。 研究小组将部署多功能空气载拉曼激光雷达（MARLI）和仅纳迪尔空降的多普勒激光雷达（ADL），以提供水蒸气，温度，空气垂直速度以及在NSF/NCAR C-130研究飞机下的含量，空气垂直速度以及在NSF/NCAR C-130研究飞机下进行MMBL热点和动态群体，并在分布。 对玛丽和ADL数据的分析，结合了凯撒期间的其他观察结果和建模，将使团队能够专注于了解上游边界层分层和风，MBL滚动和小规模的垂直运动以及表面通量以及大气边界层（ABL）顶部夹带/混合/混合控制MBL在CAOS期间的发展和进化。 此外，这些测量结果将解决气溶胶，MBL过程和云动力学（层状和对流云）如何影响混合相云特性，尤其是液体冰质量分配。该项目的主要资金来自北极自然科学计划的部分资金，来自物理和动态气象学计划。 凯撒观察资产的部署由大气研究和教育计划的设施提供资金。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。