Aerosol Influences on Ice Formation in Arctic Cold Air Outbreak Clouds during Cold-Air outbreak Experiment in the Sub-Arctic Region (CAESAR)

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，但由于对北极云层未来行为的质疑，不确定性也随之增加。 一个主要的不确定性领域是在冷空气爆发期间形成的云的性质，在那里，北极冰层上的非常冷的空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）的观测数据以及在次北极地区冷空气爆发实验（CAESAR）期间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方进行。 CAESAR期间收集的观测数据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，以便为气候模型和预测提供信息。 该项目还将有助于改善对与海军行动、商业航运和沿海社区有重大关系的天气灾害的预报。 更广泛的实地工作包括为学生和早期职业科学家，国际合作和公共宣传的重要机会。 该项目的一个关键补充是将早期职业研究人员纳入飞行科学家的角色，为他们提供宝贵的培训机会。 该奖项旨在限制与冷空气爆发（CAO）云系统相关的主要冰成核粒子（INP）来源和浓度，从而支持对微物理过程演变及其在协作云建模模拟中的描述的理解。 数据将用于回答有关INP的来源，主要成核模式以及冰川作用如何发生的问题。 将使用配备MSP-4240气溶胶浓缩器的科罗拉多圣大学（CSU）连续流扩散室（CFDC）进行实时INP测量。 此外，将收集过滤器样品，用于使用CSU冰谱仪离线测量浸没冷冻INP浓度。 该项目的主要资金来自物理和动力气象学计划，部分资金来自北极自然科学计划。 CAESAR观测资产的部署由大气研究和教育设施计划资助。该奖项反映了NSF的法定使命，并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，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 key addition from this project is in the inclusion of early-career researchers in the role of flight scientist, providing them with an valuable training opportunity. This award will seek to constrain primary ice nucleating particle (INP) sources and concentrations associated with cold air outbreak (CAO) cloud systems, thereby supporting the understanding of the evolution of microphysical processes and their description in collaborative cloud modeling simulations. Data will be used to answer questions about the source of the INP, the primary nucleation mode, and how glaciation occurs. Real-time INP measurements will be made using the Colorado St. Univ. (CSU) Continuous Flow Diffusion Chamber (CFDC) augmented with an MSP-4240 aerosol concentrator. In addition, filter samples will be collected for offline measurements of immersion freezing INP concentrations with the CSU ice spectrometer. 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.