Attributing near-surface atmospheric trends in the Fram Strait region to regional sea ice conditions

IF 4.4 2区地球科学 Q1 GEOGRAPHY, PHYSICAL

Cryosphere Pub Date : 2023-08-03 DOI:10.5194/tc-17-3115-2023

A. Schmitt, C. Lüpkes

{"title":"Attributing near-surface atmospheric trends in the Fram Strait region to regional sea ice conditions","authors":"A. Schmitt, C. Lüpkes","doi":"10.5194/tc-17-3115-2023","DOIUrl":null,"url":null,"abstract":"Abstract. Arctic sea ice has declined in all seasons accompanied by rapid atmospheric warming. Here, the focus lies on the\nwider Fram Strait region where the connection between trends in observed near-surface variables (temperature, humidity, wind speed) and local sea ice conditions are analyzed. Reanalysis data from ERA5 and MERRA-2 and Special Sensor Microwave/Imager ARTIST Sea Ice (SSM/I-ASI) sea ice concentrations for the winters of 1992 to 2022 are used for the analyses. Two focus regions are identified for which trends are largest. In the western Nansen Basin (WNB), sea ice cover decreased by −10 % per decade with especially large open water areas in 2022, and temperature and humidity increased by up to 3.7 K and 0.29 g kg−1 per decade, respectively. In the Greenland sea region (GRL), trends were slightly smaller, with −4.7 % per decade for sea ice and up to 1.3 K and 0.15 g kg−1 per decade for temperature and humidity. Trends for wind speed were mostly not significant. As a next step, two typical flow directions for this region were studied: cold-air outbreaks with northerly winds originating from ice covered areas (off-ice flow) and warm-air intrusions with southerly winds from open ocean regions (on-ice flow). To identify possible relationships between sea ice changes and atmospheric trends, correlation maps were calculated, and the results for off- and on-ice flow were compared. Up to two thirds of the observed temperature and humidity variability in both regions are related to upstream sea ice variability and an influence of sea ice cover is still present up to 500 km downstream of the ice edge. In the marginal sea ice zone the impact of a decreasing sea ice cover in this region is largest for off-ice flow conditions during cold-air outbreaks.\n","PeriodicalId":56315,"journal":{"name":"Cryosphere","volume":" ","pages":""},"PeriodicalIF":4.4000,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cryosphere","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/tc-17-3115-2023","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}

引用次数: 1

Abstract

Abstract. Arctic sea ice has declined in all seasons accompanied by rapid atmospheric warming. Here, the focus lies on the wider Fram Strait region where the connection between trends in observed near-surface variables (temperature, humidity, wind speed) and local sea ice conditions are analyzed. Reanalysis data from ERA5 and MERRA-2 and Special Sensor Microwave/Imager ARTIST Sea Ice (SSM/I-ASI) sea ice concentrations for the winters of 1992 to 2022 are used for the analyses. Two focus regions are identified for which trends are largest. In the western Nansen Basin (WNB), sea ice cover decreased by −10 % per decade with especially large open water areas in 2022, and temperature and humidity increased by up to 3.7 K and 0.29 g kg−1 per decade, respectively. In the Greenland sea region (GRL), trends were slightly smaller, with −4.7 % per decade for sea ice and up to 1.3 K and 0.15 g kg−1 per decade for temperature and humidity. Trends for wind speed were mostly not significant. As a next step, two typical flow directions for this region were studied: cold-air outbreaks with northerly winds originating from ice covered areas (off-ice flow) and warm-air intrusions with southerly winds from open ocean regions (on-ice flow). To identify possible relationships between sea ice changes and atmospheric trends, correlation maps were calculated, and the results for off- and on-ice flow were compared. Up to two thirds of the observed temperature and humidity variability in both regions are related to upstream sea ice variability and an influence of sea ice cover is still present up to 500 km downstream of the ice edge. In the marginal sea ice zone the impact of a decreasing sea ice cover in this region is largest for off-ice flow conditions during cold-air outbreaks.

查看原文本刊更多论文

将海峡地区近地面大气趋势归因于区域海冰状况

摘要随着大气快速变暖，北极海冰在所有季节都在减少。在这里，重点放在弗拉姆海峡沿岸地区，在那里分析了观测到的近地表变量（温度、湿度、风速）的趋势与当地海冰条件之间的联系。分析使用了1992年至2022年冬季ERA5和MERRA-2以及特殊传感器微波/成像仪ARTIST海冰（SSM/I-ASI）海冰浓度的再分析数据。确定了两个趋势最大的重点区域。在南森盆地西部（WNB），海冰覆盖减少了−10 % 2022年，开放水域面积特别大，温度和湿度每十年增加3.7 K和0.29 g 千克−每十年一次。在格陵兰海域（GRL），趋势略小，为−4.7 % 海冰为每十年，最高可达1.3 K和0.15 g kg−温度和湿度为每十年1次。风速的趋势大多不显著。作为下一步，研究了该地区的两个典型流动方向：来自冰层覆盖地区的带有北风的冷空气爆发（冰外流动）和来自公海地区的带有南风的暖空气入侵（冰上流动）。为了确定海冰变化和大气趋势之间的可能关系，计算了相关图，并对冰下和冰上流动的结果进行了比较。在这两个地区观测到的温度和湿度变化中，多达三分之二与上游海冰变化有关，海冰覆盖的影响仍然存在，高达500 冰缘下游km处。在边缘海冰区，该地区海冰覆盖减少对冷空气爆发期间冰外流动条件的影响最大。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Cryosphere GEOGRAPHY, PHYSICAL-GEOSCIENCES, MULTIDISCIPLINARY

CiteScore

8.70

自引率

17.30%

发文量

240

审稿时长

4-8 weeks

期刊介绍： The Cryosphere (TC) is a not-for-profit international scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of frozen water and ground on Earth and on other planetary bodies. The main subject areas are the following: ice sheets and glaciers; planetary ice bodies; permafrost and seasonally frozen ground; seasonal snow cover; sea ice; river and lake ice; remote sensing, numerical modelling, in situ and laboratory studies of the above and including studies of the interaction of the cryosphere with the rest of the climate system.