{"title":"近几十年来北太平洋维多利亚模式对印度夏季季风开始的影响增强","authors":"Suqin Zhang, Xia Qu, Gang Huang","doi":"10.1186/s40562-024-00324-y","DOIUrl":null,"url":null,"abstract":"Victoria mode (VM), the second dominant mode of North Pacific sea surface temperature variability, has been identified as one of the important factors influencing the Indian summer monsoon (ISM) onset. The positive phase of the May VM delays the ISM onset by both tropical and extratropical pathways. Here, we found a significant interdecadal enhancement of their relationship since the early 1990s, which is mainly attributed to the structure changes and increased variance of the VM. In recent decades, the VM has shown more significant warm SST anomalies in the tropical central Pacific, which drive the large-scale divergent circulation more effectively. This enhanced divergent circulation leads to low-level divergence and reduced rainfall in the tropical Asian summer monsoon region. The reduced rainfall excites equatorial Rossby wave response and anomalous easterly winds in the northern Indian Ocean, delaying the ISM onset. Besides, the increased variance of the VM after 1992/1993 stimulates a stronger extratropical Rossby wave train. This stationary Rossby wave train induces a stronger cooling to the northwest of India, which weakens the land-sea thermal contrast and leads to the delayed ISM onset. This finding should be taken into account to improve short-term predictions of the monsoon onset.","PeriodicalId":48596,"journal":{"name":"Geoscience Letters","volume":"244 1","pages":""},"PeriodicalIF":4.0000,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Enhanced impacts of the North Pacific Victoria mode on the Indian summer monsoon onset in recent decades\",\"authors\":\"Suqin Zhang, Xia Qu, Gang Huang\",\"doi\":\"10.1186/s40562-024-00324-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Victoria mode (VM), the second dominant mode of North Pacific sea surface temperature variability, has been identified as one of the important factors influencing the Indian summer monsoon (ISM) onset. The positive phase of the May VM delays the ISM onset by both tropical and extratropical pathways. Here, we found a significant interdecadal enhancement of their relationship since the early 1990s, which is mainly attributed to the structure changes and increased variance of the VM. In recent decades, the VM has shown more significant warm SST anomalies in the tropical central Pacific, which drive the large-scale divergent circulation more effectively. This enhanced divergent circulation leads to low-level divergence and reduced rainfall in the tropical Asian summer monsoon region. The reduced rainfall excites equatorial Rossby wave response and anomalous easterly winds in the northern Indian Ocean, delaying the ISM onset. Besides, the increased variance of the VM after 1992/1993 stimulates a stronger extratropical Rossby wave train. This stationary Rossby wave train induces a stronger cooling to the northwest of India, which weakens the land-sea thermal contrast and leads to the delayed ISM onset. This finding should be taken into account to improve short-term predictions of the monsoon onset.\",\"PeriodicalId\":48596,\"journal\":{\"name\":\"Geoscience Letters\",\"volume\":\"244 1\",\"pages\":\"\"},\"PeriodicalIF\":4.0000,\"publicationDate\":\"2024-02-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Geoscience Letters\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1186/s40562-024-00324-y\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geoscience Letters","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1186/s40562-024-00324-y","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
维多利亚模式(VM)是北太平洋海面温度变化的第二主导模式,已被确定为影响印度夏季季风(ISM)开始的重要因素之一。五月 VM 的正相位通过热带和外热带路径延迟了 ISM 的开始。在这里,我们发现自 20 世纪 90 年代初以来,它们之间的关系出现了显著的年代际增强,这主要归因于 VM 的结构变化和方差增大。近几十年来,VM 在热带中太平洋表现出更显著的暖 SST 异常,更有效地驱动了大尺度发散环流。这种增强的发散环流导致热带亚洲夏季季风区的低层发散和降雨量减少。降雨量的减少激发了印度洋北部的赤道罗斯比波响应和异常东风,推迟了国际海洋气象机制的发生。此外,1992/1993 年后增加的 VM 变异激发了更强的外热带罗斯比波列。这个静止的罗斯比波列引起印度西北部更强的降温,从而削弱了陆海热对比,导致国际海洋气象机制推迟出现。应考虑这一发现,以改进对季风开始的短期预测。
Enhanced impacts of the North Pacific Victoria mode on the Indian summer monsoon onset in recent decades
Victoria mode (VM), the second dominant mode of North Pacific sea surface temperature variability, has been identified as one of the important factors influencing the Indian summer monsoon (ISM) onset. The positive phase of the May VM delays the ISM onset by both tropical and extratropical pathways. Here, we found a significant interdecadal enhancement of their relationship since the early 1990s, which is mainly attributed to the structure changes and increased variance of the VM. In recent decades, the VM has shown more significant warm SST anomalies in the tropical central Pacific, which drive the large-scale divergent circulation more effectively. This enhanced divergent circulation leads to low-level divergence and reduced rainfall in the tropical Asian summer monsoon region. The reduced rainfall excites equatorial Rossby wave response and anomalous easterly winds in the northern Indian Ocean, delaying the ISM onset. Besides, the increased variance of the VM after 1992/1993 stimulates a stronger extratropical Rossby wave train. This stationary Rossby wave train induces a stronger cooling to the northwest of India, which weakens the land-sea thermal contrast and leads to the delayed ISM onset. This finding should be taken into account to improve short-term predictions of the monsoon onset.
Geoscience LettersEarth and Planetary Sciences-General Earth and Planetary Sciences
CiteScore
4.90
自引率
2.50%
发文量
42
审稿时长
25 weeks
期刊介绍:
Geoscience Letters is the official journal of the Asia Oceania Geosciences Society, and a fully open access journal published under the SpringerOpen brand. The journal publishes original, innovative and timely research letter articles and concise reviews on studies of the Earth and its environment, the planetary and space sciences. Contributions reflect the eight scientific sections of the AOGS: Atmospheric Sciences, Biogeosciences, Hydrological Sciences, Interdisciplinary Geosciences, Ocean Sciences, Planetary Sciences, Solar and Terrestrial Sciences, and Solid Earth Sciences. Geoscience Letters focuses on cutting-edge fundamental and applied research in the broad field of the geosciences, including the applications of geoscience research to societal problems. This journal is Open Access, providing rapid electronic publication of high-quality, peer-reviewed scientific contributions.