Journal article
Dynamical mechanisms linking Indian monsoon precipitation and the circumglobal teleconnection
- Abstract:
- The circumglobal teleconnection (CGT) is an important mode of circulation variability, with an influence across many parts of the northern hemisphere. Here, we examine the excitation mechanisms of the CGT in the ECMWF seasonal forecast model, and the relationship between the Indian summer monsoon (ISM), the CGT and the extratropical northern hemisphere circulation. Results from relaxation experiments, in which the model is corrected to reanalysis in specific regions, suggest that errors over northwest Europe are more important in inhibiting the model skill at representing the CGT, in addition to northern hemisphere skill more widely, than west-central Asia and the ISM region, although the link between ISM precipitation and the extratropical circulation is weak in all experiments. Thermal forcing experiments in the ECMWF model, in which a heating is applied over India, suggest that the ISM does force an extratropical Rossby wave train, with upper tropospheric anticyclonic anomalies over east Asia, the North Pacific and North America associated with increased ISM heating. However, this eastward-propagating branch of the wave train does not project into Europe, and the response there occurs largely through westward-propagating Rossby waves. Results from barotropic model experiments show a response that is highly consistent with the seasonal forecast model, with similar eastward- and westward-propagating Rossby waves. This westward-propagating response is shown to be important in the downstream reinforcement of the wave train between Asia and North America.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 12.9MB, Terms of use)
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- Publisher copy:
- 10.1007/s00382-021-05825-6
Authors
- Publisher:
- Springer
- Journal:
- Climate Dynamics More from this journal
- Volume:
- 57
- Issue:
- 9-10
- Pages:
- 2615–2636
- Publication date:
- 2021-06-27
- Acceptance date:
- 2021-05-24
- DOI:
- EISSN:
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1432-0894
- ISSN:
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0930-7575
- Language:
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English
- Keywords:
- Pubs id:
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1181046
- Local pid:
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pubs:1181046
- Deposit date:
-
2021-06-08
- ARK identifier:
Terms of use
- Copyright holder:
- Beverley et al.
- Copyright date:
- 2021
- Rights statement:
- © The Author(s) 2021. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
- Licence:
- CC Attribution (CC BY)
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