Asymmetry of the Distribution of Vertical Velocities of the Extratropical Atmosphere in Theory, Models and Reanalysis

IF 3 3区 地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES Journal of the Atmospheric Sciences Pub Date : 2024-01-08 DOI:10.1175/jas-d-23-0128.1
M. Kohl, P. O’Gorman
{"title":"Asymmetry of the Distribution of Vertical Velocities of the Extratropical Atmosphere in Theory, Models and Reanalysis","authors":"M. Kohl, P. O’Gorman","doi":"10.1175/jas-d-23-0128.1","DOIUrl":null,"url":null,"abstract":"\nThe vertical velocity distribution in the atmosphere is asymmetric with stronger upward than downward motion. This asymmetry has important implications for the distribution of precipitation and its extremes and for an effective static stability that has been used to represent the effects of latent heating on extratropical eddies. Idealized GCM simulations show that the asymmetry increases as the climate warms, but current moist dynamical theories based around small amplitude modes greatly overestimate the increase in asymmetry with warming found in the simulations. Here, we first analyze the changes in asymmetry with warming using numerical inversions of a moist quasigeostrophic omega equation applied to output from the idealized GCM. The inversions show that increases in the asymmetry with warming in the GCM simulations are primarily related to decreases in moist static stability on the left-hand side of the moist omega equation, whereas the dynamical forcing on the right-hand side of the omega equation is unskewed and contributes little to the asymmetry of the vertical velocity distribution. By contrast, increases in asymmetry with warming for small amplitude modes are related to changes in both moist static stability and dynamical forcing leading to enhanced asymmetry in warm climates. We distill these insights into a toy model of the moist omega equation that is solved for a given moist static stability and wavenumber of the dynamical forcing. In comparison to modal theory, the toy model better reproduces the slow increase of the asymmetry with climate warming in the idealized GCM simulations and over the seasonal cycle from winter to summer in reanalysis.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":null,"pages":null},"PeriodicalIF":3.0000,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Atmospheric Sciences","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/jas-d-23-0128.1","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
引用次数: 0

Abstract

The vertical velocity distribution in the atmosphere is asymmetric with stronger upward than downward motion. This asymmetry has important implications for the distribution of precipitation and its extremes and for an effective static stability that has been used to represent the effects of latent heating on extratropical eddies. Idealized GCM simulations show that the asymmetry increases as the climate warms, but current moist dynamical theories based around small amplitude modes greatly overestimate the increase in asymmetry with warming found in the simulations. Here, we first analyze the changes in asymmetry with warming using numerical inversions of a moist quasigeostrophic omega equation applied to output from the idealized GCM. The inversions show that increases in the asymmetry with warming in the GCM simulations are primarily related to decreases in moist static stability on the left-hand side of the moist omega equation, whereas the dynamical forcing on the right-hand side of the omega equation is unskewed and contributes little to the asymmetry of the vertical velocity distribution. By contrast, increases in asymmetry with warming for small amplitude modes are related to changes in both moist static stability and dynamical forcing leading to enhanced asymmetry in warm climates. We distill these insights into a toy model of the moist omega equation that is solved for a given moist static stability and wavenumber of the dynamical forcing. In comparison to modal theory, the toy model better reproduces the slow increase of the asymmetry with climate warming in the idealized GCM simulations and over the seasonal cycle from winter to summer in reanalysis.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
理论、模式和再分析中热带外大气垂直速度分布的不对称性
大气中的垂直速度分布是不对称的,向上运动强于向下运动。这种不对称对降水及其极端降水的分布和有效静态稳定性有重要影响,而有效静态稳定性被用来表示潜热对热带外漩涡的影响。理想化的 GCM 模拟显示,不对称会随着气候变暖而增加,但目前以小振幅模式为基础的湿动力学理论大大高估了模拟中发现的不对称随气候变暖而增加的情况。在这里,我们首先利用对理想化 GCM 输出结果进行的湿润类逆变欧米茄方程数值反演,分析了不对称随气候变暖而发生的变化。反演结果表明,在 GCM 模拟中,随气候变暖而增加的不对称性主要与潮湿欧米茄方程左侧潮湿静力稳定性的降低有关,而欧米茄方程右侧的动力强迫是不偏斜的,对垂直速度分布的不对称性影响很小。相反,随着气候变暖,小振幅模式的不对称性增加,这与潮湿静力稳定性和动力强迫的变化有关,导致温暖气候下不对称性增强。我们将这些见解提炼成一个湿润欧米茄方程的玩具模型,该模型可根据给定的湿润静态稳定性和动力强迫的波数求解。与模态理论相比,玩具模型更好地再现了理想化 GCM 模拟中气候变暖以及再分析中从冬季到夏季的季节周期中不对称现象的缓慢增加。
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 去求助
来源期刊
Journal of the Atmospheric Sciences
Journal of the Atmospheric Sciences 地学-气象与大气科学
CiteScore
0.20
自引率
22.60%
发文量
196
审稿时长
3-6 weeks
期刊介绍: The Journal of the Atmospheric Sciences (JAS) publishes basic research related to the physics, dynamics, and chemistry of the atmosphere of Earth and other planets, with emphasis on the quantitative and deductive aspects of the subject. The links provide detailed information for readers, authors, reviewers, and those who wish to submit a manuscript for consideration.
期刊最新文献
Dynamic and Thermodynamic Environmental Modulation of Tropical Congestus and Cumulonimbus in Maritime Tropical Regions Evaluation of the aggregation efficiency modeling at colder atmospheric temperatures in comparison to satellite observations Monsoonal MCS Initiation, Rainfall, and Diurnal Gravity Waves over the Bay of Bengal: Observation and a Linear Model Eye Formation and energetics in a dry model of hurricane-like vortices The Role of Turbulence in an Intense Tropical Cyclone: Momentum Diffusion, Eddy Viscosities, and Mixing Lengths
×
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
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 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 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1