气候变化领域集成服务门户(CCPortal): Australia-Asian monsoon in two versions of the UK Met Office Unified Model and their impacts on tropical

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DOI	10.1007/s00382-019-04821-1
	Australia-Asian monsoon in two versions of the UK Met Office Unified Model and their impacts on tropical–extratropical teleconnections
	Jin L.; Zhang H.; Moise A.; Martin G.; Milton S.; Rodriguez J.
发表日期	2019
ISSN	0930-7575
起始页码	4717
结束页码	4741
卷号	53 期号:2020-07-08
英文摘要	Many climate models have dry biases in tropical monsoon regions, but it is less clear how these errors can affect these model-simulated tropical–extratropical interactions and rainfall teleconnections. In this study, we evaluate the Australia and Asian (A–A) monsoon rainfall in two versions [Global Atmosphere version 6 (GA6), and version 7 (GA7)] of the UK Met Office Unified Model (UM) with uncoupled atmosphere-only simulations using two horizontal resolutions (N96 ~ 135 km and N216 ~ 60 km). Although UM can capture broad features of rainfall seasonal variations in the monsoon region, there are significant model errors in the locations of monsoon rainfall, its magnitudes and time evolutions, especially a climatological rainfall dry bias over the Indian subcontinent. This dry bias is progressively reduced by increased model resolutions from N96 to N216 and improved model physics from GA6 to GA7. Area-averaged peak monsoon rainfall over the Indian subcontinent (70°–90°E, 5°–25°N) increases by ~ 70% from 3 mm day−1 in GA6N216 to 5 mm day−1 in GA7N216, and rainfall dry bias averaged over a large tropical Asian monsoon domain is reduced by 2/3. In the uncoupled atmosphere-only experiment, the model rainfall is excessively sensitive to its underlying SST conditions, with positive local SST-rainfall correlations occurring over whole tropical oceans, while observations show negative correlations in regions dominated by atmospheric influence although such model performance is improved in its fully coupled runs. Most significant improvement of monsoon rainfall and ENSO (El Nino Southern Oscillations) relationship in GA7 occurred in the Australian continent, with GA7N216 better capturing the observed relationship than GA6N216. Although GA7N216 still suffers a dry bias in the Indian monsoon region, the increased monsoon rainfall substantially increases atmospheric diabatic heating over the region in the middle-upper troposphere, leading to more realistic extratropical circulation Gill-type responses to the heating. This results in improved monsoon-desert rainfall teleconnections, more realistic linkage between tropical Asian monsoon with its subtropical East Asian component, and its interhemispheric influence in Southern Hemisphere. Such results are further confirmed by the model nudging experiments in which the atmospheric wind and temperature are nudged towards observations over the Indian monsoon domain. Our study clearly demonstrates that uncertainty associated with monsoon simulations needs to be considered in future climate projections even outside the monsoon domain. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
语种	英语
scopus关键词	air-sea interaction; atmospheric modeling; extratropical environment; monsoon; precipitation (climatology); seasonal variation; teleconnection; tropical environment; Asia; Australia
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/145949
作者单位	Institute of Desert Meteorology, China Meteorological Administration, Urumqi, China; Desert Atmosphere and Environment Observation Station at Taklimakan, Tazhong, China; Bureau of Meteorology, GPO Box 1289k, Melbourne, VIC 3001, Australia; Met Office, FitzRoy Road, Exeter, Devon EX1 3PB, United Kingdom
推荐引用方式 GB/T 7714	Jin L.,Zhang H.,Moise A.,等. Australia-Asian monsoon in two versions of the UK Met Office Unified Model and their impacts on tropical–extratropical teleconnections[J],2019,53(2020-07-08).
APA	Jin L.,Zhang H.,Moise A.,Martin G.,Milton S.,&Rodriguez J..(2019).Australia-Asian monsoon in two versions of the UK Met Office Unified Model and their impacts on tropical–extratropical teleconnections.Climate Dynamics,53(2020-07-08).
MLA	Jin L.,et al."Australia-Asian monsoon in two versions of the UK Met Office Unified Model and their impacts on tropical–extratropical teleconnections".Climate Dynamics 53.2020-07-08(2019).