Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022
The annual minimum Antarctic sea ice extent (SIE) in February 2022 hits a record low in the satellite era, with less than 2 million square kilometres observed on 25 February 2022, contrasting with the slightly positive trend in the Antarctic SIE prior to 2014. However, the preceding Amundsen Sea Low...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/acc9d6 |
| _version_ | 1827869816586764288 |
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| author | Shaoyin Wang Jiping Liu Xiao Cheng Dongxia Yang Tobias Kerzenmacher Xinqing Li Yongyun Hu Peter Braesicke |
| author_facet | Shaoyin Wang Jiping Liu Xiao Cheng Dongxia Yang Tobias Kerzenmacher Xinqing Li Yongyun Hu Peter Braesicke |
| author_sort | Shaoyin Wang |
| collection | DOAJ |
| description | The annual minimum Antarctic sea ice extent (SIE) in February 2022 hits a record low in the satellite era, with less than 2 million square kilometres observed on 25 February 2022, contrasting with the slightly positive trend in the Antarctic SIE prior to 2014. However, the preceding Amundsen Sea Low (ASL) in austral spring 2021 was the deepest since 1950. According to a linear regression model, the very low ASL contributed about 60% to the record low SIE in 2022. This study further investigates the underlying mechanism. The investigation of the lagged impact of the ASL on Antarctic SIE is based on observational data and state-of-the-art simulations. We found that (a) the deepened ASL associated with strengthened southerly winds accelerates the sea ice export away from the western Antarctic continent in spring, leading to the expansion of coastal polynyas (open water areas); (b) through the positive ice-ocean albedo feedback, the lack of the sea ice off the coastline enhances solar heating in the upper ocean and further sea ice melting in summer can occur. Specifically, in spring 2021, the deepest ASL is accompanied by a large sea-ice area flux of about 17.6 × 10 ^3 km ^2 across 70° S over the Ross Sea in October and November, contributing to a significant increase in net surface radiation of 20–30 W m ^−2 and upper ocean warming of about 0.5 K in summer. Therefore, the deepened ASL in spring 2021 plays a crucial role for the record low Antarctic SIE in February 2022. In addition, it is found that both the La Niña conditions and the strong stratospheric polar vortex contributed significantly to the very strong ASL in 2021. Currently, nearly 2/3 of Earth system models in the Coupled Model Intercomparison Project Phase 6 have difficulties capturing the relationship between the ASL and the Antarctic SIE. |
| first_indexed | 2024-03-12T15:50:26Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:50:26Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-f9acf226c359459ea44fd1fe8b46976e2023-08-09T15:16:30ZengIOP PublishingEnvironmental Research Letters1748-93262023-01-0118505400210.1088/1748-9326/acc9d6Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022Shaoyin Wang0Jiping Liu1Xiao Cheng2Dongxia Yang3Tobias Kerzenmacher4https://orcid.org/0000-0001-8413-0539Xinqing Li5Yongyun Hu6Peter Braesicke7School of Geospatial Engineering and Science, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) , Zhuhai, People’s Republic of China; Key Laboratory of Comprehensive Observation of Polar Environment (Sun Yat-sen University), Ministry of Education , Zhuhai, People’s Republic of China; University Corporation for Polar Research , Zhuhai, People’s Republic of ChinaDepartment of Atmospheric and Environmental Sciences, State University of New York at Albany , Albany, NY, United States of AmericaSchool of Geospatial Engineering and Science, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) , Zhuhai, People’s Republic of China; Key Laboratory of Comprehensive Observation of Polar Environment (Sun Yat-sen University), Ministry of Education , Zhuhai, People’s Republic of China; University Corporation for Polar Research , Zhuhai, People’s Republic of ChinaARC Centre of Excellence for Climate Extremes, University of Melbourne , Melbourne, VIC, Australia; Analycia Pty. Ltd, Melbourne, VIC, AustraliaKarlsruhe Institute of Technology, Institute of Meteorology and Climate Research , Karlsruhe, GermanySchool of Geospatial Engineering and Science, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) , Zhuhai, People’s Republic of China; University Corporation for Polar Research , Zhuhai, People’s Republic of ChinaDepartment of Atmospheric and Oceanic Sciences, School of Physics, Peking University , Beijing, People’s Republic of ChinaKarlsruhe Institute of Technology, Institute of Meteorology and Climate Research , Karlsruhe, GermanyThe annual minimum Antarctic sea ice extent (SIE) in February 2022 hits a record low in the satellite era, with less than 2 million square kilometres observed on 25 February 2022, contrasting with the slightly positive trend in the Antarctic SIE prior to 2014. However, the preceding Amundsen Sea Low (ASL) in austral spring 2021 was the deepest since 1950. According to a linear regression model, the very low ASL contributed about 60% to the record low SIE in 2022. This study further investigates the underlying mechanism. The investigation of the lagged impact of the ASL on Antarctic SIE is based on observational data and state-of-the-art simulations. We found that (a) the deepened ASL associated with strengthened southerly winds accelerates the sea ice export away from the western Antarctic continent in spring, leading to the expansion of coastal polynyas (open water areas); (b) through the positive ice-ocean albedo feedback, the lack of the sea ice off the coastline enhances solar heating in the upper ocean and further sea ice melting in summer can occur. Specifically, in spring 2021, the deepest ASL is accompanied by a large sea-ice area flux of about 17.6 × 10 ^3 km ^2 across 70° S over the Ross Sea in October and November, contributing to a significant increase in net surface radiation of 20–30 W m ^−2 and upper ocean warming of about 0.5 K in summer. Therefore, the deepened ASL in spring 2021 plays a crucial role for the record low Antarctic SIE in February 2022. In addition, it is found that both the La Niña conditions and the strong stratospheric polar vortex contributed significantly to the very strong ASL in 2021. Currently, nearly 2/3 of Earth system models in the Coupled Model Intercomparison Project Phase 6 have difficulties capturing the relationship between the ASL and the Antarctic SIE.https://doi.org/10.1088/1748-9326/acc9d6Antarctic sea iceAmundsen sea lowwind-driven ice driftice-ocean albedo feedbackCMIP6 |
| spellingShingle | Shaoyin Wang Jiping Liu Xiao Cheng Dongxia Yang Tobias Kerzenmacher Xinqing Li Yongyun Hu Peter Braesicke Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 Environmental Research Letters Antarctic sea ice Amundsen sea low wind-driven ice drift ice-ocean albedo feedback CMIP6 |
| title | Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 |
| title_full | Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 |
| title_fullStr | Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 |
| title_full_unstemmed | Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 |
| title_short | Contribution of the deepened Amundsen sea low to the record low Antarctic sea ice extent in February 2022 |
| title_sort | contribution of the deepened amundsen sea low to the record low antarctic sea ice extent in february 2022 |
| topic | Antarctic sea ice Amundsen sea low wind-driven ice drift ice-ocean albedo feedback CMIP6 |
| url | https://doi.org/10.1088/1748-9326/acc9d6 |
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