Increasing heat waves frequencies over India during post-El Niño spring and early summer seasons

IF 4 1区 地球科学 Q1 GEOGRAPHY, PHYSICAL
G.Ch. Satyanarayana , Sambasivarao Velivelli , K. Koteswara Rao , Jasti S. Chowdary , Anant Parekh , C. Gnanaseelan
{"title":"Increasing heat waves frequencies over India during post-El Niño spring and early summer seasons","authors":"G.Ch. Satyanarayana ,&nbsp;Sambasivarao Velivelli ,&nbsp;K. Koteswara Rao ,&nbsp;Jasti S. Chowdary ,&nbsp;Anant Parekh ,&nbsp;C. Gnanaseelan","doi":"10.1016/j.gloplacha.2024.104561","DOIUrl":null,"url":null,"abstract":"<div><p>The increasing frequency of extreme Heat Waves (HWs) has generated significant societal impacts in recent years. This study used different observational datasets to investigate the HW characteristics over India during the post-El Niño spring and early summer seasons (April to June; AMJ). Analysis suggests that HW days are more prevalent over India, predominantly increased in south-central and northwest India, during the decaying phase of strong El Niño years. It is found that anomalous anticyclone circulation accompanied by high pressure extending from the Western North Pacific region towards the Bay of Bengal and India is responsible for enhanced HW days and intensity during the AMJ of strong El Niño decay years. This anomalous anticyclone-induced downdraft reduces the specific humidity in the lower troposphere, leading to decreased cloud cover over India. As a result, shortwave radiation is enhanced at the surface, which causes abnormal HWs over India. During the decaying phase of strong El Niño years, the HW days over India contributed to an increase in the frequency of Discomfort Index hours (above 28 °C), maximum temperatures exceeding 40 °C (hours per day), and Universal Thermal Climate Index days above 38 °C and 46 °C during the spring and early summer months, especially in the East Coast, central, and northwestern parts of India. Thus, proper prediction of large-scale atmospheric circulation over the Indo-western Pacific region during El Niño can help to predict the HW conditions three months in advance. This would help to implement suitable adaptation measures and put into practice strong mitigation policies to limit the increased risk of such events during AMJ of El Niño decay years.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"241 ","pages":"Article 104561"},"PeriodicalIF":4.0000,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Global and Planetary Change","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S092181812400208X","RegionNum":1,"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: 0

Abstract

The increasing frequency of extreme Heat Waves (HWs) has generated significant societal impacts in recent years. This study used different observational datasets to investigate the HW characteristics over India during the post-El Niño spring and early summer seasons (April to June; AMJ). Analysis suggests that HW days are more prevalent over India, predominantly increased in south-central and northwest India, during the decaying phase of strong El Niño years. It is found that anomalous anticyclone circulation accompanied by high pressure extending from the Western North Pacific region towards the Bay of Bengal and India is responsible for enhanced HW days and intensity during the AMJ of strong El Niño decay years. This anomalous anticyclone-induced downdraft reduces the specific humidity in the lower troposphere, leading to decreased cloud cover over India. As a result, shortwave radiation is enhanced at the surface, which causes abnormal HWs over India. During the decaying phase of strong El Niño years, the HW days over India contributed to an increase in the frequency of Discomfort Index hours (above 28 °C), maximum temperatures exceeding 40 °C (hours per day), and Universal Thermal Climate Index days above 38 °C and 46 °C during the spring and early summer months, especially in the East Coast, central, and northwestern parts of India. Thus, proper prediction of large-scale atmospheric circulation over the Indo-western Pacific region during El Niño can help to predict the HW conditions three months in advance. This would help to implement suitable adaptation measures and put into practice strong mitigation policies to limit the increased risk of such events during AMJ of El Niño decay years.

在厄尔尼诺现象后的春季和初夏季节,印度上空的热浪频率越来越高
近年来,极端热浪(HWs)日益频繁,对社会产生了重大影响。本研究利用不同的观测数据集,调查了后厄尔尼诺春季和初夏季节(4 月至 6 月;AMJ)印度上空的热浪特征。分析表明,在强厄尔尼诺年的衰减阶段,印度上空的高温日较多,主要在印度中南部和西北部增加。研究发现,在强厄尔尼诺衰减年的 AMJ 期间,异常反气旋环流伴随着高压从北太平洋西部地区向孟加拉湾和印度延伸,是造成 HW 日数和强度增加的原因。这种反气旋引起的异常下沉气流降低了对流层下部的比湿度,导致印度上空的云量减少。因此,地表短波辐射增强,导致印度上空出现异常高湿。在强厄尔尼诺年的衰减阶段,印度上空的高湿日导致春季和初夏月份,特别是印度东海岸、中部和西北部地区的不舒适指数小时数(超过 28 °C)、最高气温超过 40 °C(每天小时数)以及全球热气候指数超过 38 °C和 46 °C的频率增加。因此,在厄尔尼诺现象期间,对印度-西太平洋地区大尺度大气环流的适当预测有助于提前三个月预测高温条件。这将有助于在厄尔尼诺衰减年的 AMJ 期间采取适当的适应措施和实施强有力的缓解政策,以限制此类事件增加的风险。
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
Global and Planetary Change
Global and Planetary Change 地学天文-地球科学综合
CiteScore
7.40
自引率
10.30%
发文量
226
审稿时长
63 days
期刊介绍: The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems. Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged. Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.
×
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