The impact of the QBO vertical structure on June extreme high temperatures in South Asia

IF 8.5 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

npj Climate and Atmospheric Science Pub Date : 2024-10-07 DOI:10.1038/s41612-024-00791-2

Jiali Luo, Fuhai Luo, Fei Xie, Xiao Chen, Zhenhua Wang, Wenshou Tian, Fangrui Zhu, Mingzhen Gu

{"title":"The impact of the QBO vertical structure on June extreme high temperatures in South Asia","authors":"Jiali Luo, Fuhai Luo, Fei Xie, Xiao Chen, Zhenhua Wang, Wenshou Tian, Fangrui Zhu, Mingzhen Gu","doi":"10.1038/s41612-024-00791-2","DOIUrl":null,"url":null,"abstract":"Using observation data and numerical simulations, we have demonstrated that the stratospheric Quasi-Biennial Oscillation (QBO) can predict extreme high temperatures (EHTs) in South Asia in June. The vertical structure of the QBO plays a crucial role in this prediction. When the QBO in June shows easterlies (westerlies) at 50 hPa and westerlies (easterlies) at 70 hPa, more (fewer) EHT events occur. This likely results from the QBO’s vertical structure causing positive (negative) temperature anomalies in the lower stratosphere and negative (positive) static stability anomalies near the tropical tropopause. These anomalies enhance (weaken) convective activity over the equatorial Indian Ocean, leading to anomalous circulation with ascending (descending) air over the equatorial Indian Ocean and descending (ascending) air over northern and central South Asia. This suppresses (promotes) convection over northern and central South Asia, affecting cloud formation and precipitation. Consequently, more (less) solar radiation reaches the region, along with weaker (stronger) evaporative cooling effects, warming (cooling) the surface and creating a background state conducive to (against) EHT events. Additionally, the opposite zonal winds at 30 hPa and 50 hPa in April may serve as a reference factor for predicting the probability of EHT events in northern and central South Asia. This study provides a potential approach for forecasting tropospheric extreme weather events based on stratospheric signals.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-8"},"PeriodicalIF":8.5000,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00791-2.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"npj Climate and Atmospheric Science","FirstCategoryId":"89","ListUrlMain":"https://www.nature.com/articles/s41612-024-00791-2","RegionNum":1,"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

Using observation data and numerical simulations, we have demonstrated that the stratospheric Quasi-Biennial Oscillation (QBO) can predict extreme high temperatures (EHTs) in South Asia in June. The vertical structure of the QBO plays a crucial role in this prediction. When the QBO in June shows easterlies (westerlies) at 50 hPa and westerlies (easterlies) at 70 hPa, more (fewer) EHT events occur. This likely results from the QBO’s vertical structure causing positive (negative) temperature anomalies in the lower stratosphere and negative (positive) static stability anomalies near the tropical tropopause. These anomalies enhance (weaken) convective activity over the equatorial Indian Ocean, leading to anomalous circulation with ascending (descending) air over the equatorial Indian Ocean and descending (ascending) air over northern and central South Asia. This suppresses (promotes) convection over northern and central South Asia, affecting cloud formation and precipitation. Consequently, more (less) solar radiation reaches the region, along with weaker (stronger) evaporative cooling effects, warming (cooling) the surface and creating a background state conducive to (against) EHT events. Additionally, the opposite zonal winds at 30 hPa and 50 hPa in April may serve as a reference factor for predicting the probability of EHT events in northern and central South Asia. This study provides a potential approach for forecasting tropospheric extreme weather events based on stratospheric signals.

Abstract Image

查看原文本刊更多论文

QBO 垂直结构对南亚 6 月极端高温的影响

利用观测数据和数值模拟，我们证明平流层准双年涛动（QBO）可以预测南亚六月份的极端高温。QBO 的垂直结构在这一预测中起着至关重要的作用。当 6 月份的 QBO 在 50 hPa 显示东风（西风），在 70 hPa 显示西风（东风）时，极端高温事件就会增多（减少）。这可能是由于 QBO 的垂直结构造成了平流层下部的正（负）温度异常和热带对流层顶附近的负（正）静态稳定异常。这些异常现象增强（削弱）了赤道印度洋上空的对流活动，导致赤道印度洋上空的空气上升（下降），而南亚北部和中部的空气下降（上升）的异常环流。这抑制（促进）了南亚北部和中部的对流，影响了云的形成和降水。因此，到达该地区的太阳辐射增多（减少），蒸发冷却效应减弱（增强），使地表变暖（变冷），形成有利于（不利于）高温热气流事件的背景状态。此外，4 月份 30 hPa 和 50 hPa 的反向带状风可作为预测南亚北部和中部发生极端高温天气概率的参考因素。这项研究为根据平流层信号预报对流层极端天气事件提供了一种可能的方法。

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

npj Climate and Atmospheric Science Earth and Planetary Sciences-Atmospheric Science

CiteScore

8.80

自引率

3.30%

发文量

审稿时长

21 weeks

期刊介绍： npj Climate and Atmospheric Science is an open-access journal encompassing the relevant physical, chemical, and biological aspects of atmospheric and climate science. The journal places particular emphasis on regional studies that unveil new insights into specific localities, including examinations of local atmospheric composition, such as aerosols. The range of topics covered by the journal includes climate dynamics, climate variability, weather and climate prediction, climate change, ocean dynamics, weather extremes, air pollution, atmospheric chemistry (including aerosols), the hydrological cycle, and atmosphere–ocean and atmosphere–land interactions. The journal welcomes studies employing a diverse array of methods, including numerical and statistical modeling, the development and application of in situ observational techniques, remote sensing, and the development or evaluation of new reanalyses.