RAPID: What Caused the Record Warmth and Loss of Antarctic Sea ice in the Austral Summer of 2022, and will Sea Ice Remain Low Over 2022-2024?

RAPID：是什么导致 2022 年南半球夏季南极海冰出现创纪录的变暖和损失？2022-2024 年海冰是否会保持较低水平？

• 批准号: 2233016
• 负责人: Edward Blanchard-Wrigglesworth
• 金额: $ 8.42万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2233016&HistoricalAwards=false
• 关键词: RAPID; What; Caused; Record; Warmth

In the austral winter of 2021/2022 a drastic decline in Antarctic sea ice extent has taken place, and February 2022 marked the lowest sea ice extent on record since satellite sea ice observations began in 1979. Combined with the loss of sea ice, the most extreme heat wave ever observed took place over East Antarctica in March 2022 as temperatures climbed over +40°C from climatology. Extreme events have an oversized footprint in socioeconomic impacts, but also serve as litmus tests for climate predictions. This project will use novel tools to diagnose the factors that led to the record low Antarctic sea ice extent and heat wave focusing on the impact of winds and ocean temperatures. Currently (June 2022) Antarctic sea ice extent remains at record low levels for the time of year, raising the prospect of a long-lasting period of low sea ice extent, yet annual forecasts of Antarctic sea ice do not yet exist. To address this issue, this project will also create exploratory annual sea ice forecasts for the 2022-2024 period. The extreme changes observed in Antarctic sea ice extent and air temperature have questioned our current understanding of Antarctic climate variability. Motivated by the timing of these events and our recent development of novel analysis tools, this project will address the following research questions:(R1) Can local winds account for the observed 2021/2022 sea ice loss, or are remote sea surface temperature (SST) anomalies a necessary ingredient?(R2) Are sea ice conditions over 2022-2024 likely to remain anomalously low?(R3) Can a state-of-the-art climate model simulate a heat wave of comparable magnitude to that observed if it follows the observed circulation that led to the heat wave?The main approach will be to use a nudging technique with a climate model, in which one or several variables in a climate model are nudged toward observed values. The project authors used this tool to attribute Antarctic sea ice variability and trends over 1979-2018 to winds and SST anomalies. This project will apply this tool to the period 2019-2022 to address R1 and R3 by running two different model experiments over this time period in which the winds over Antarctica and SSTs in the Southern Ocean are nudged toward observed values. In addition, we will diagnose the relevant modes of atmospheric variability over 2019-2022 that are known to influence Antarctic sea ice to gain further insight into the 2022 loss of sea ice extent. To address R2, we plan to extend the model simulations but without nudging, using the model as a forecast model (as its 2022 initial conditions will be taken from the end of the nudged simulations and capture important aspects of the observed state). We expect that if current upper ocean heat content is anomalously high, low sea ice extent conditions may continue over 2022-2024, as happened over 2017-2019 following the previous record low of sea ice extent in 2016/2017. To further address R3, we will compare observations and model simulations using novel atmospheric heat transport calculations developed by the project team.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.

在2021/2022年澳大利亚冬季，南极海冰范围发生了急剧下降，2022年2月标志着自1979年卫星海冰观测开始以来，海冰的最低水平是记录的。结合了海冰的丧失，有史以来观察到的最极端的热量波浪在2022年3月在2022年在2022年在2022年的加速度 +40°Clasticy cligation +40°cligation cligation cligation cligation +40°c campation。极端事件在社会经济影响方面具有超大的占地面积，但也可以作为气候预测的石蕊测试。该项目将使用新颖的工具来诊断导致低南极海冰范围的创纪录的因素，而热浪则集中在风和海洋温度的影响上。目前（2022年6月）南极海冰范围在一年中的时间保持较低的水平，这增加了持续持续的低海冰范围的前景，但对南极海冰的年度预测尚不存在。为了解决这个问题，该项目还将在2022 - 2024年期间创建探索性的年度海冰森林。在南极海冰范围和空气温度下观察到的极端变化质疑了我们目前对南极气候变异性的理解。由于这些事件的时间安排和我们最近开发的新型分析工具的动机，该项目将解决以下研究问题：（R1）当地风能解释观察到的2021/2022海冰损失，或者远程海面温度（SST）异常是必要的诱导吗？观察到的幅度是否遵循导致热浪的观察到的循环？主要的方法是使用具有气候模型的淡淡技术，其中气候模型中的一个或几个变量被轻推针对观察值。该项目作者使用此工具将南极海冰的可变性和1979 - 2018年的趋势归因于风和SST异常。该项目将在2019 - 2022年期间应用该工具，以通过在此期间运行两个不同的模型实验来解决R1和R3，在此期间，南极和南大洋中SST的风被倾向于观察到的值。此外，我们将诊断2019 - 2022年间大气变异性的相关模式，这些模式会影响南极海冰，以进一步深入了解2022年海冰范围丧失。为了解决R2，我们计划扩展模型仿真，但在不私人的情况下，使用模型作为预测模型（因为它的2022初始条件将从裸模拟的末尾进行，并捕获观察到的状态的重要方面）。我们预计，如果当前海洋热含量是异常的，那么在2017 - 2019年间，在2017 - 2019年以前的海冰范围低时，海冰范围可能会持续到2022 - 2024年。为了进一步解决R3，我们将使用项目团队开发的新型大气热传输计算进行比较观察和模型模拟。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审查标准，认为值得通过评估来获得支持。

项目成果

SIPN South: six years of coordinated seasonal Antarctic sea ice predictions

• DOI: 10.3389/fmars.2023.1148899
• 发表时间: 2023-05
• 作者: F. Massonnet;S. Barreira;A. Barthélemy;R. Bilbao;E. Blanchard‐Wrigglesworth;E. Blockley;D. Bromwich;M. Bushuk;Xiaoran Dong;H. Goessling;W. Hobbs;D. Iovino;Woo-Sung Lee;Cuihua Li;W. Meier;W. Merryfield;E. Moreno‐Chamarro;Y. Morioka;Xuewei Li;B. Niraula;A. Petty;A. Sanna;Mariana Scilingo;Qi Shu;M. Sigmond;Nico Sun;S. Tietsche;Xingren Wu;Qinghua Yang;X. Yuan

The Largest Ever Recorded Heatwave—Characteristics and Attribution of the Antarctic Heatwave of March 2022

有记录以来最大的热浪——2022 年 3 月南极热浪的特征和归因

• DOI: 10.1029/2023gl104910
• 发表时间: 2023
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Blanchard‐Wrigglesworth, Edward;Cox, Tyler;Espinosa, Zachary I.;Donohoe, Aaron
• 通讯作者: Donohoe, Aaron

Winds and Meltwater Together Lead to Southern Ocean Surface Cooling and Sea Ice Expansion

风和融水共同导致南大洋表面冷却和海冰膨胀

• DOI: 10.1029/2023gl105948
• 发表时间: 2023
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Roach, Lettie A.;Mankoff, Kenneth D.;Romanou, Anastasia;Blanchard‐Wrigglesworth, Edward;Haine, Thomas W. N.;Schmidt, Gavin. A.
• 通讯作者: Schmidt, Gavin. A.