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DOI	10.1007/s00382-020-05270-x
	The effect of vertical ocean mixing on the tropical Atlantic in a coupled global climate model
	Deppenmeier A.-L.; Haarsma R.J.; LeSager P.; Hazeleger W.
发表日期	2020
ISSN	0930-7575
起始页码	5089
结束页码	5109
卷号	54
英文摘要	Sea surface temperature (SST) biases in the tropical Atlantic are a long-standing problem among coupled global climate models (CGCMs). They occur in equilibrated state, as well as in initialised seasonal to decadal simulations. The bias is typically characterised by too high SST in upwelling regions and associated errors of wind and precipitation. We examine the SST bias in the state-of-the-art CGCM EC-Earth by means of an upper ocean heat budget analysis. Horizontal advection processes affect the SST bias development only to a small extent, and surface heat fluxes mostly dampen the warm bias. Subgrid-scale upper ocean vertical mixing is too low in EC-Earth when compared to estimates from reanalysis data, potentially giving rise to the warm bias. We perform sensitivity experiments to examine the effect of enhanced vertical mixing on the SST bias in quasi equilibrium present day climate and its impact on projected climate change. Enhanced mixing in historical simulation mode (MixUp pr) reduces the SST bias in the tropical Atlantic compared to the control experiment (Control pr). Associated atmospheric biases of precipitation and surface winds are also reduced in MixUp pr. We further perform climate projections under the RCP8.5 emission scenario (Control fu and MixUp fu). Under increasing greenhouse gas forcing, the tropical Atlantic warms by up to 4.5∘C locally, and maritime precipitation increases in boreal winter and spring. We show that the vertical mixing parameterisation influences future climate. In MixUp fu, SSTs remain 0.5∘C colder in boreal winter and spring, but increase with the same amplitude in summer and fall. The strength and location of the projected intertropical convergence zone also depends on the ocean vertical mixing efficiency. The rain band moves southward in summer, and its strength increases in winter in MixUp fu as compared to Control fu. © 2020, The Author(s).
英文关键词	Climate change projection; Climate modeling; Coupled global climatemodels; Ocean vertical mixing; Parameterisations; Sea surface temperature bias; Tropical Atlantic
语种	英语
scopus关键词	atmosphere-ocean coupling; climate modeling; computer simulation; efficiency measurement; error analysis; future prospect; numerical model; precipitation (climatology); sea surface temperature; vertical mixing; wind field; Atlantic Ocean; Atlantic Ocean (Tropical)
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/145432
作者单位	Meteorology and Air Quality, Wageningen University, Wageningen, Netherlands; Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands; Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
推荐引用方式 GB/T 7714	Deppenmeier A.-L.,Haarsma R.J.,LeSager P.,et al. The effect of vertical ocean mixing on the tropical Atlantic in a coupled global climate model[J],2020,54.
APA	Deppenmeier A.-L.,Haarsma R.J.,LeSager P.,&Hazeleger W..(2020).The effect of vertical ocean mixing on the tropical Atlantic in a coupled global climate model.Climate Dynamics,54.
MLA	Deppenmeier A.-L.,et al."The effect of vertical ocean mixing on the tropical Atlantic in a coupled global climate model".Climate Dynamics 54(2020).