Scientific Program Overview (SPO): Cold Air Outbreak Experiment in the Sub-Arctic Region

科学计划概述（SPO）：亚北极地区的冷空气爆发实验

• 批准号: 2016368
• 负责人: Paquita Zuidema
• 金额: $ 2.82万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2016368&HistoricalAwards=false
• 关键词: Scientific; Program; Overview; SPO; Cold

The Arctic is the region on planet Earth warming the most rapidly with rapid sea ice loss and increasing air temperatures reinforcing each other. Changing ice cover posts great uncertainties on Arctic winter weather and significant impacts upon coastal communities and local transportation. In addition, how the high-latitude changes connect to the mid-latitude and the global climate system is another challenging question. One particularly poorly understood weather regime is cold-air outbreaks when cold Arctic air streaming over relatively warm open ocean water. During cold-air outbreaks, relatively warm moist air is transported up in forming lines of clouds. Little is known about the cloud properties and their rain and snowfall amount in relation with the accompanying vertical air movement and sea surface conditions. Cold air outbreaks occasionally spawn into intense circular air movements, “polar lows”. Cold-air outbreaks have significant impacts on the global heat and water transport as well as ocean circulations. Despite their impacts on weather and climate, cold-air outbreaks remain difficult to predict. This awarded project is to plan a dedicated field study, Cold Air Outbreak Experiment in the Sub Arctic Region (CAESAR) that has the goal to gather the necessary measurements to understand the mysterious cloud regime associated with cold-air outbreaks. The planned field campaign will be in collaboration with Scandinavian scientists and provide unique training opportunities to students to be the next generation of atmospheric scientists. The CAESAR field campaign is anticipated in February-March 2022 over the Norwegian Sea, a spot where cold-air outbreaks are prevalent. The NSF/NCAR C-130 aircraft with a suite of radars, Lidars, radiometers, aerosol, cloud, precipitation and trace gas probes will be deployed from northern Sweden or Norway. The goal is to study the structure of marine boundary layer clouds during cold-air outbreaks with a focus on fully sampling microphysical (liquid and ice) properties of cloud particles and the accompanying dynamics. Flight plans are designed to investigate cold-air outbreaks throughout their entire evolution from their initiation over the Arctic sea ice edge to well-developed cloud structures far downstream. The CAESAR measurements will not only afford new insights of development of fine-scale cloud structures but also constrain a hierarchy of numerical models ranging from eddy simulations capable of capturing the nuanced small-scale cloud and dynamical processes to numerical weather and climate models. A dedicated model-observational intercomparison project is planned to improve numerical models particularly their performance in the ‘grey-zone’ where state-of-the-art weather models fail to capture the relevant cloud and dynamical processes.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.

北极是地球上的区域，随着海冰快速损失和空气温度的增加，彼此相互加强。变化的冰盖对北极冬季天气以及对沿海社区和当地运输的重大影响非常不确定性。此外，高纬度变化如何连接到中纬度和全球气候系统是另一个挑战问题。一个特别糟糕的天气制度是冷空气爆发，当冷空气在相对温暖的开阔海水上流动时。在冷空气暴发期间，相对温暖的潮湿空气被形成云层。关于参与垂直空气运动和海面条件的云特性及其降雨和降雪量知之甚少。冷空气暴发有时会产生巨大的圆形空气运动，即“极性低点”。冷空气暴发对全球热量和水运输以及海洋循环产生重大影响。尽管它们对天气和气候产生了影响，但冷空气暴发仍然很难预测。这个奖励的项目是计划在北极地区（凯撒）进行专门的现场研究，冷空气暴发实验，该实验的目标是收集必要的测量值，以了解与冷空气爆发相关的神秘云制度。计划的现场运动将与斯堪的纳维亚科学家合作，并为学生提供独特的培训机会，成为下一代大气科学家。预计凯撒田间运动将于2022年2月3月在挪威海上进行，挪威海洋爆发很普遍。 NSF/NCAR C-130飞机配备了一套雷达，激光射频，辐射仪，气溶胶，云，降水和痕量气探针，将从瑞典北部或挪威部署。目的是研究冷空气暴发期间海洋边界层云的结构，重点是对云颗粒的完全采样微物理（液体和冰）和参与动力学。飞行计划旨在调查整个整个北极海冰边缘的启动，再到遥远的云层结构。凯撒测量结果不仅将提供高规模云结构开发的新见解，而且还限制了数值模型的层次结构，从能够捕获细微的小规模云和动态过程到数值天气和气候模型的涡模拟范围。计划为改善数值模型，特别是在“灰色区”中的表现，在“灰区”中，最先进的天气模型无法捕获相关的云和动态过程。该奖项反映了NSF的法定任务，并通过使用基金会的知识绩效和广泛的criperia来评估，这奖项反映了NSF的法定任务。