Mesoscale Dynamics and Mixed-phase Microphysics in Arctic Cold Air Outbreaks

北极气候变化的速度比地球上任何地方都快。气候预测表明，北极将继续变暖，但由于对北极云未来行为的质疑，出现了不确定性。一个主要的不确定性领域是在冷空气爆发期间形成的云层的特性，在冷空气爆发期间，北极冰层上的非常冷的气团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(和降水)的观测数据，以及将于2024年春季在斯堪的纳维亚半岛北部进行的次北极地区冷空气爆发实验期间海洋和大气之间的能量交换。凯撒期间收集的观测结果将用于更好地了解冷空气爆发系统和更广泛的北极气候系统的特征，以便为气候模型和预测提供信息。该项目还将有助于改进对天气灾害的预报，对海军行动、商业航运和沿海社区具有重要意义。更广泛的领域努力包括为学生和职业早期科学家提供重要机会、国际合作和公共宣传。该奖项的一个独特方面是指导NCAR大气研究和科学重大机会(SOARS)计划的一名学生，该计划是一个从本科生到研究生的桥梁计划，旨在扩大历史上代表性不足的社区在大气和相关科学方面的参与。该项目将侧重于精确分辨的降水垂直断面和来自机载多普勒雷达的运动学数据，以及现场云和降水探测器，从而为凯撒的总体目标作出贡献。该奖项的科学目标是：1)描述冷空气爆发(CAO)中海洋边界层对流的垂直结构和环流，以阐明云过程在CAO云系和极地低的中尺度组织中的作用；2)记录水流星的大小和相位分布，以阐明初级和次级冰过程对降水产生和云动力学的作用。该团队将负责安装和试飞Ka波段降水雷达(KPR)，开发改进的怀俄明州云雷达(WCR)水流星垂直速度剖面数据集，开发QA/QC D和处理后的KPR反射率和多普勒速度数据集，开发WCR双多普勒速度合成数据集，提供从WCR和其他传感器反演冰水含量(IWC)和其他云和降水产品，以及提供来自nezorov探测器的现场液态水含量(LWC)/IWC。该项目的主要资金来自物理和动态气象计划，部分资金来自北极自然科学计划。为凯撒部署观测资源由大气研究和教育设施项目提供资金。这一奖励反映了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。

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 in an effort to better understand the characteristics of the cold-air outbreak system, and the Arctic climate system more broadly, in order 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. A unique aspect of this award is the mentorship of a student in the NCAR Significant Opportunities in Atmospheric Research and Science (SOARS) program, which is an undergraduate-to-graduate bridge program designed to broaden participation of historically underrepresented communities in atmospheric and related science. This project will contribute to the overall CAESAR goals by focusing on the finely resolved vertical transects of precipitation and kinematic data from airborne Doppler radars, and in situ cloud and precipitation probes. The scientific objectives of this award are to: 1) to characterize the vertical structure and circulations of Marine Boundary Layer (MBL) convection in cold-air outbreaks (CAOs), in order to elucidate the role of cloud processes in the mesoscale organization of the CAO cloud regime, and in polar lows; and 2) to document the size and phase distribution of hydrometeors, in order to elucidate the roles of primary and secondary ice processes on precipitation generation and cloud dynamics. The team will be responsible for installing and test-flying the Ka-band Precipitation Radar (KPR), developing an improved Wyoming Cloud Radar (WCR) hydrometeor vertical velocity profile dataset, developing the QA/QC’d and processed KPR reflectivity and Doppler velocity dataset, developing the WCR dual-Doppler velocity synthesis dataset, providing the retrieval of Ice Water Content (IWC) and other cloud and precipitation products from WCR and other sensors, and providing in-situ Liquid Water Content (LWC)/IWC from the Nevzorov probe.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.