Suppression of cold air outbreaks over the interior of North America in a warmer climate

IF 4.8 2区 地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES
Kara Hartig, Eli Tziperman
{"title":"Suppression of cold air outbreaks over the interior of North America in a warmer climate","authors":"Kara Hartig, Eli Tziperman","doi":"10.1175/jcli-d-23-0477.1","DOIUrl":null,"url":null,"abstract":"Abstract In spite of the mean warming trend over the last few decades and its amplification in the Arctic, some studies have found no robust decline or even a slight increase in wintertime cold air outbreaks over North America. But fossil evidence from warmer paleoclimate periods indicates that the interior of North America never dropped below freezing even in the depths of winter, which implies that the maintenance of cold air outbreaks is unlikely to continue indefinitely with future warming. To identify key mechanisms affecting cold air outbreaks and understand how and why they will change in a warmer climate, we examine the development of North American cold air outbreaks in both a pre-industrial and a roughly 8×CO2 scenario using the Community Earth System Model, CESM2. We observe a sharp drop-off in the wintertime temperature distribution at the freezing temperature, suppressing below-freezing conditions in the warmer climate and above-freezing conditions in the pre-industrial case. The disappearance of Arctic sea ice and loss of the near-surface temperature inversion dramatically decrease the availability of below-freezing air in source regions. Using an air parcel trajectory analysis, we demonstrate a remarkable similarity in both the dynamics and diabatic effects acting on cold air masses in the two climate scenarios. Diabatic temperature evolution along cold air outbreak trajectories is a competition between cooling from longwave radiation and warming from boundary layer mixing. Surprisingly, while both diabatic effects strengthen in the warmer climate, the balance remains the same, with a net cooling of about −6 K over 10 days.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"149 1","pages":""},"PeriodicalIF":4.8000,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Climate","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/jcli-d-23-0477.1","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
引用次数: 0

Abstract

Abstract In spite of the mean warming trend over the last few decades and its amplification in the Arctic, some studies have found no robust decline or even a slight increase in wintertime cold air outbreaks over North America. But fossil evidence from warmer paleoclimate periods indicates that the interior of North America never dropped below freezing even in the depths of winter, which implies that the maintenance of cold air outbreaks is unlikely to continue indefinitely with future warming. To identify key mechanisms affecting cold air outbreaks and understand how and why they will change in a warmer climate, we examine the development of North American cold air outbreaks in both a pre-industrial and a roughly 8×CO2 scenario using the Community Earth System Model, CESM2. We observe a sharp drop-off in the wintertime temperature distribution at the freezing temperature, suppressing below-freezing conditions in the warmer climate and above-freezing conditions in the pre-industrial case. The disappearance of Arctic sea ice and loss of the near-surface temperature inversion dramatically decrease the availability of below-freezing air in source regions. Using an air parcel trajectory analysis, we demonstrate a remarkable similarity in both the dynamics and diabatic effects acting on cold air masses in the two climate scenarios. Diabatic temperature evolution along cold air outbreak trajectories is a competition between cooling from longwave radiation and warming from boundary layer mixing. Surprisingly, while both diabatic effects strengthen in the warmer climate, the balance remains the same, with a net cooling of about −6 K over 10 days.
在气候变暖的情况下抑制冷空气在北美内陆爆发
摘要 尽管在过去几十年里平均气温呈上升趋势并在北极地区有所扩大,但一些研究发现北美地区冬季冷空气爆发并没有明显减少,甚至略有增加。但来自较暖古气候时期的化石证据表明,即使在深冬时节,北美洲内陆地区的气温也从未降至零度以下,这意味着随着未来气候变暖,冷空气爆发现象不太可能无限期地持续下去。为了确定影响冷空气爆发的关键机制,并了解在气候变暖的情况下冷空气爆发将如何以及为何发生变化,我们利用群落地球系统模型 CESM2 研究了工业化前和大约 8×CO2 情景下北美冷空气爆发的发展情况。我们观察到冬季气温分布在冰点温度时急剧下降,在气候变暖的情况下抑制了冰点以下的情况,而在工业化前的情况下则抑制了冰点以上的情况。北极海冰的消失和近地面温度反转的消失极大地减少了冰点以下空气在源区的可用性。通过空气包裹轨迹分析,我们证明了在两种气候情景下,冷空气团的动力学和二重效应具有显著的相似性。沿冷空气爆发轨迹的二重温度演变是长波辐射降温和边界层混合升温之间的竞争。令人惊讶的是,虽然在较暖的气候条件下这两种减热效应都会增强,但平衡却保持不变,10 天内净降温约 -6 K。
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
Journal of Climate
Journal of Climate 地学-气象与大气科学
CiteScore
9.30
自引率
14.30%
发文量
490
审稿时长
7.5 months
期刊介绍: The Journal of Climate (JCLI) (ISSN: 0894-8755; eISSN: 1520-0442) publishes research that advances basic understanding of the dynamics and physics of the climate system on large spatial scales, including variability of the atmosphere, oceans, land surface, and cryosphere; past, present, and projected future changes in the climate system; and climate simulation and prediction.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信