Opposing Changes in Indian Summer Monsoon Rainfall Variability Produced by Orbital and Anthropogenic Forcing
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Published:2024-09-05
Issue:17
Volume:51
Page:
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ISSN:0094-8276
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Container-title:Geophysical Research Letters
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language:en
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Short-container-title:Geophysical Research Letters
Author:
He Jiazhi1,
Sun Weiyi12ORCID,
Wang Bin3ORCID,
Liu Jian14ORCID,
Ning Liang1,
Yan Mi1ORCID
Affiliation:
1. Key Laboratory for Virtual Geographic Environment Ministry of Education State Key Laboratory Cultivation Base of Geographical Environment Evolution of Jiangsu Province Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application School of Geography Science Nanjing Normal University Nanjing China
2. Regional Climate Group Department of Earth Sciences University of Gothenburg Gothenburg Sweden
3. Department of Atmospheric Sciences and International Pacific Research Center University of Hawaii at Manoa Honolulu HI USA
4. Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Science Nanjing Normal University Nanjing China
Abstract
AbstractFuture projections indicate that Indian Summer Monsoon Rainfall (ISMR) faces a “wetter and more variable” climate. However, the reasons remain uncertain. The Last Interglacial (LIG) climate provides a potential analog for future warming. Investigating ISMR responses to these two warming scenarios could help understand the causes of ISMR changes. Using PMIP4 simulations, we find that ISMR became “wetter and more stable” during the LIG, contrasting the future climate. The opposing changes in ISMR variability are related to divergent changes in the El Niño‐Southern Oscillation (ENSO) amplitudes, ENSO‐ISMR relationships, and ENSO‐induced large‐scale atmospheric circulation anomalies. During the LIG, orbital forcing weakened ENSO variability and its impacts on ISMR. A westward positioning of ENSO shifted the atmospheric circulation anomalies westward, suppressing extreme ISMR anomalies. These processes are supported by atmospheric model simulations. Our results suggest that different warming patterns (dynamic effects) are more critical than moisture‐increasing effects in controlling regional climate variability.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Priority Academic Program Development of Jiangsu Higher Education Institutions
National Science Foundation
Swedish Foundation for International Cooperation in Research and Higher Education
Publisher
American Geophysical Union (AGU)