Arctic amplification‐induced intensification of planetary wave modulational instability: A simplified theory of enhanced large‐scale waviness

IF 3 3区 地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES
Dehai Luo, Binhe Luo, Wenqi Zhang, Wenqin Zhuo, Ian Simmonds, Yao Yao
{"title":"Arctic amplification‐induced intensification of planetary wave modulational instability: A simplified theory of enhanced large‐scale waviness","authors":"Dehai Luo, Binhe Luo, Wenqi Zhang, Wenqin Zhuo, Ian Simmonds, Yao Yao","doi":"10.1002/qj.4740","DOIUrl":null,"url":null,"abstract":"In the mid–high latitude atmosphere, the instability of planetary waves characterizes enhanced planetary wave activity or amplified large‐scale waviness leading to increased regional weather extremes. In this paper, a nonlinear Schrödinger equation is derived to describe the evolution of planetary waves. Then the consequences of Arctic amplification (AA)‐induced meridional background potential vorticity (PV<jats:sub><jats:italic>y</jats:italic></jats:sub>) changes on the modulational instability of planetary waves are examined. It is found that the modulational instability of uniform planetary wave trains mainly results from the presence of high‐order dispersion and nonlinearity, even though such an instability depends on the amplitude, vertical structure and zonal wavenumber of uniform planetary waves and the atmospheric stratification. Because the nonlinearity and high‐order dispersion depend on the magnitude of PV<jats:sub><jats:italic>y</jats:italic></jats:sub>, the modulational instability of planetary waves is significantly influenced by the variation of PV<jats:sub><jats:italic>y</jats:italic></jats:sub> associated with AA. It is also revealed that stronger modulational instability of planetary waves tends to occur in the smaller PV<jats:sub><jats:italic>y</jats:italic></jats:sub> region or in higher latitudes due to both stronger nonlinearity and weaker high‐order dispersion for fixed background and planetary wave parameters, which is conducive to more intense large‐scale waviness. However, because AA can reduce PV<jats:sub><jats:italic>y</jats:italic></jats:sub> in the mid–high latitudes mainly in the lower troposphere via reductions of winter zonal winds and meridional temperature gradients, the reduced PV<jats:sub><jats:italic>y</jats:italic></jats:sub> under AA can significantly enhance the modulational instability. Thus, the role of AA is to amplify planetary wave activity in mid–high latitudes through strengthening the modulational instability of planetary waves due to reduced PV<jats:sub><jats:italic>y</jats:italic></jats:sub>, which further enhances large‐scale waviness.","PeriodicalId":49646,"journal":{"name":"Quarterly Journal of the Royal Meteorological Society","volume":null,"pages":null},"PeriodicalIF":3.0000,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Quarterly Journal of the Royal Meteorological Society","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/qj.4740","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

In the mid–high latitude atmosphere, the instability of planetary waves characterizes enhanced planetary wave activity or amplified large‐scale waviness leading to increased regional weather extremes. In this paper, a nonlinear Schrödinger equation is derived to describe the evolution of planetary waves. Then the consequences of Arctic amplification (AA)‐induced meridional background potential vorticity (PVy) changes on the modulational instability of planetary waves are examined. It is found that the modulational instability of uniform planetary wave trains mainly results from the presence of high‐order dispersion and nonlinearity, even though such an instability depends on the amplitude, vertical structure and zonal wavenumber of uniform planetary waves and the atmospheric stratification. Because the nonlinearity and high‐order dispersion depend on the magnitude of PVy, the modulational instability of planetary waves is significantly influenced by the variation of PVy associated with AA. It is also revealed that stronger modulational instability of planetary waves tends to occur in the smaller PVy region or in higher latitudes due to both stronger nonlinearity and weaker high‐order dispersion for fixed background and planetary wave parameters, which is conducive to more intense large‐scale waviness. However, because AA can reduce PVy in the mid–high latitudes mainly in the lower troposphere via reductions of winter zonal winds and meridional temperature gradients, the reduced PVy under AA can significantly enhance the modulational instability. Thus, the role of AA is to amplify planetary wave activity in mid–high latitudes through strengthening the modulational instability of planetary waves due to reduced PVy, which further enhances large‐scale waviness.
北极放大引起的行星波调制不稳定性增强:大尺度波浪增强的简化理论
在中高纬度大气层中,行星波的不稳定性表现为行星波活动增强或大尺度波性放大,从而导致区域极端天气增加。本文推导了一个非线性薛定谔方程来描述行星波的演变。然后研究了北极放大(AA)引起的子午线背景势涡度(PVy)变化对行星波调制不稳定性的影响。研究发现,均匀行星波列的调制不稳定性主要源于高阶色散和非线性的存在,尽管这种不稳定性取决于均匀行星波的振幅、垂直结构和带状波数以及大气分层。由于非线性和高阶色散取决于 PVy 的大小,行星波的调制不稳定性受到与 AA 有关的 PVy 变化的显著影响。研究还发现,在背景和行星波参数固定的情况下,由于较强的非线性和较弱的高阶色散,行星波较强的调制不稳定性往往发生在 PVy 较小的区域或较高纬度地区,这有利于产生更强烈的大尺度波浪。然而,由于 AA 主要通过减少冬季带风和经向温度梯度来降低中高纬度对流层低层的 PVy,因此在 AA 作用下降低的 PVy 可以显著增强调制不稳定性。因此,AA 的作用是通过减少 PVy 来加强行星波的调制不稳定性,从而放大中高纬度地区的行星波活动,进一步增强大尺度波浪性。
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
CiteScore
16.80
自引率
4.50%
发文量
163
审稿时长
3-8 weeks
期刊介绍: The Quarterly Journal of the Royal Meteorological Society is a journal published by the Royal Meteorological Society. It aims to communicate and document new research in the atmospheric sciences and related fields. The journal is considered one of the leading publications in meteorology worldwide. It accepts articles, comprehensive review articles, and comments on published papers. It is published eight times a year, with additional special issues. The Quarterly Journal has a wide readership of scientists in the atmospheric and related fields. It is indexed and abstracted in various databases, including Advanced Polymers Abstracts, Agricultural Engineering Abstracts, CAB Abstracts, CABDirect, COMPENDEX, CSA Civil Engineering Abstracts, Earthquake Engineering Abstracts, Engineered Materials Abstracts, Science Citation Index, SCOPUS, Web of Science, and more.
×
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