气候变化领域集成服务门户(CCPortal): The impact of air–sea coupling and ocean biases on the seasonal cycle of southern West African precipitation

CCPortal

DOI	10.1007/s00382-019-04973-0
	The impact of air–sea coupling and ocean biases on the seasonal cycle of southern West African precipitation
	Wainwright C.M.; Hirons L.C.; Klingaman N.P.; Allan R.P.; Black E.; Turner A.G.
发表日期	2019
ISSN	0930-7575
起始页码	7027
结束页码	7044
卷号	53 期号:11
英文摘要	The biannual seasonal rainfall regime over the southern part of West Africa is characterised by two wet seasons, separated by the ‘Little Dry Season’ in July–August. Lower rainfall totals during this intervening dry season may be detrimental for crop yields over a region with a dense population that depends on agricultural output. Coupled Model Intercomparison Project Phase 5 (CMIP5) models do not correctly capture this seasonal regime, and instead generate a single wet season, peaking at the observed timing of the Little Dry Season. Hence, the realism of future climate projections over this region is questionable. Here, the representation of the Little Dry Season in coupled model simulations is investigated, to elucidate factors leading to this misrepresentation. The Global Ocean Mixed Layer configuration of the Met Office Unified Model is particularly useful for exploring this misrepresentation, as it enables separating the effects of coupled model ocean biases in different ocean basins while maintaining air–sea coupling. Atlantic Ocean SST biases cause the incorrect seasonal regime over southern West Africa. Upper level descent in August reduces ascent along the coastline, which is associated with the observed reduction in rainfall during the Little Dry Season. When coupled model Atlantic Ocean biases are introduced, ascent over the coastline is deeper and rainfall totals are higher during July–August. Hence, this study indicates detrimental impacts introduced by Atlantic Ocean biases, and highlights an area of model development required for production of meaningful climate change projections over the West Africa region. © 2019, The Author(s).
英文关键词	Atlantic SST bias; Coupled models; Little Dry Season; Precipitation; Seasonal cycle; West African monsoon
语种	英语
scopus关键词	atmosphere-ocean coupling; climate modeling; CMIP; dry season; monsoon; precipitation (climatology); sea surface temperature; seasonality; Atlantic Ocean; West Africa
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/145805
作者单位	Department of Meteorology, University of Reading, Reading, United Kingdom; NCAS, University of Reading, Reading, United Kingdom; National Centre for Earth Observation (NCEO), Reading, United Kingdom
推荐引用方式 GB/T 7714	Wainwright C.M.,Hirons L.C.,Klingaman N.P.,等. The impact of air–sea coupling and ocean biases on the seasonal cycle of southern West African precipitation[J],2019,53(11).
APA	Wainwright C.M.,Hirons L.C.,Klingaman N.P.,Allan R.P.,Black E.,&Turner A.G..(2019).The impact of air–sea coupling and ocean biases on the seasonal cycle of southern West African precipitation.Climate Dynamics,53(11).
MLA	Wainwright C.M.,et al."The impact of air–sea coupling and ocean biases on the seasonal cycle of southern West African precipitation".Climate Dynamics 53.11(2019).