Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall
Abstract Simulating accurately the South Asian summer monsoon is crucial for food security of several South Asian countries yet challenging for global climate models (GCMs). The GCMs suffer from some systematic biases including dry bias in mean monsoon rainfall over the India subcontinent and excess...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-01-01
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| Series: | npj Climate and Atmospheric Science |
| Online Access: | https://doi.org/10.1038/s41612-025-00916-1 |
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| author | Gudongze Li Chun Zhao Jun Gu Jiawang Feng Mingyue Xu Xiaoyu Hao Junshi Chen Hong An Wenju Cai Tao Geng |
| author_facet | Gudongze Li Chun Zhao Jun Gu Jiawang Feng Mingyue Xu Xiaoyu Hao Junshi Chen Hong An Wenju Cai Tao Geng |
| author_sort | Gudongze Li |
| collection | DOAJ |
| description | Abstract Simulating accurately the South Asian summer monsoon is crucial for food security of several South Asian countries yet challenging for global climate models (GCMs). The GCMs suffer from some systematic biases including dry bias in mean monsoon rainfall over the India subcontinent and excessive equatorial light rain between which the relationship was rarely discussed. Numerical experiments are conducted for one month during active monsoon with global quasi-uniform resolution of 60 km (U60 km) and 3 km (U3 km) separately. Evaluation with observations shows that U3 km reduces the dry bias over northern India and excessive light rain over the equatorial Indian Ocean (EIO) that are both prominent in U60 km. Excessive light rain in U60 km contributes critically to stronger rainfall and latent heating over the EIO. A Hadley-type anomalous circulation is thus induced, whose subsidence branch suppresses updrafts and reduces moisture transport into northern India, contributing to the dry bias. The findings highlight the importance of constraining excessive light rain for regional climate projection in GCMs. |
| format | Article |
| id | doaj-art-2e7c9d789d984680bd1e6e0c4aa88324 |
| institution | Kabale University |
| issn | 2397-3722 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Climate and Atmospheric Science |
| spelling | doaj-art-2e7c9d789d984680bd1e6e0c4aa883242025-01-19T12:16:08ZengNature Portfolionpj Climate and Atmospheric Science2397-37222025-01-018111010.1038/s41612-025-00916-1Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfallGudongze Li0Chun Zhao1Jun Gu2Jiawang Feng3Mingyue Xu4Xiaoyu Hao5Junshi Chen6Hong An7Wenju Cai8Tao Geng9Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of ChinaDeep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of ChinaDeep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of ChinaDeep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of ChinaDeep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of ChinaSchool of Computer Science and Technology, University of Science and Technology of ChinaLaoshan LaboratoryLaoshan LaboratoryLaoshan LaboratoryLaoshan LaboratoryAbstract Simulating accurately the South Asian summer monsoon is crucial for food security of several South Asian countries yet challenging for global climate models (GCMs). The GCMs suffer from some systematic biases including dry bias in mean monsoon rainfall over the India subcontinent and excessive equatorial light rain between which the relationship was rarely discussed. Numerical experiments are conducted for one month during active monsoon with global quasi-uniform resolution of 60 km (U60 km) and 3 km (U3 km) separately. Evaluation with observations shows that U3 km reduces the dry bias over northern India and excessive light rain over the equatorial Indian Ocean (EIO) that are both prominent in U60 km. Excessive light rain in U60 km contributes critically to stronger rainfall and latent heating over the EIO. A Hadley-type anomalous circulation is thus induced, whose subsidence branch suppresses updrafts and reduces moisture transport into northern India, contributing to the dry bias. The findings highlight the importance of constraining excessive light rain for regional climate projection in GCMs.https://doi.org/10.1038/s41612-025-00916-1 |
| spellingShingle | Gudongze Li Chun Zhao Jun Gu Jiawang Feng Mingyue Xu Xiaoyu Hao Junshi Chen Hong An Wenju Cai Tao Geng Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall npj Climate and Atmospheric Science |
| title | Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall |
| title_full | Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall |
| title_fullStr | Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall |
| title_full_unstemmed | Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall |
| title_short | Excessive equatorial light rain causes modeling dry bias of Indian summer monsoon rainfall |
| title_sort | excessive equatorial light rain causes modeling dry bias of indian summer monsoon rainfall |
| url | https://doi.org/10.1038/s41612-025-00916-1 |
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