气候变化领域集成服务门户(CCPortal): Effect of empirical correction of sea-surface temperature biases on the CRCM5-simulated climate and projected climate changes over North America

CCPortal

DOI	10.1007/s00382-018-4596-2
	Effect of empirical correction of sea-surface temperature biases on the CRCM5-simulated climate and projected climate changes over North America
	Hernández-Díaz L.; Nikiéma O.; Laprise R.; Winger K.; Dandoy S.
发表日期	2019
ISSN	0930-7575
起始页码	453
结束页码	476
卷号	53 期号:2020-01-02
英文摘要	Dynamical downscaling (DD) consists in using archives of Coupled Global Climate Models (CGCM) simulations as the atmospheric and sea-surface boundary conditions (BC) to drive nested, Regional Climate Model (RCM) simulations. Biases in the CGCM-generated driving BC, however, can have detrimental impacts on RCM performance. It is well documented for the historical period that CGCM-simulated sea-surface temperatures (SST) suffer substantial biases, especially important near coastal regions. Assuming that these SST biases are time-invariant, they could in principle be subtracted from century-long CGCM projections before being used to drive RCMs. This paper investigates the performance of a 3-step DD approach as follows. The CGCM-simulated sea-surface temperatures (SST) are first empirically corrected by subtracting their systematic biases; the corrected SST are then used as ocean surface BC for an atmosphere-only GCM (AGCM) simulation; finally this AGCM simulation provides the atmospheric lateral BC to drive an RCM simulation. This is what we refer to as the 3-step approach CGCM–AGCM–RCM of DD, which can be compared to the traditional 2-step approach CGCM–RCM consisting of driving an RCM simulation directly by CGCM-generated BC. In this paper we compare the results obtained with the two approaches, for present and future climates under RCP8.5, using the fifth-generation Canadian Regional Climate Model (CRCM5) with a grid mesh of 0.22° over the North American CORDEX domain, driven by two CMIP5 models: the Canadian Earth System Model of the Canadian Centre for Climate modelling and analysis (CanESM2) and the Earth System Model of the Max-Planck-Institut für Meteorologie (MPI-ESM-MR). The results show that, in current climate, the seasonal-mean 2-m temperature fields simulated with the 3-step DD have generally smaller biases with respect to the observations than those simulated with the 2-step DD; in fact the performance of the 3-step DD simulations often approaches that of the reanalyses-driven simulation. For the seasonal-mean precipitation field, however, the differences between the two DD methods are not conclusive. Differences between the projected climate changes with the two DD methods vary substantially depending upon the variable being considered. Differences are particularly important for temperature: over the bulk of the North American continent, the 3-step DD projects more warming in winter and less in summer. This result highlights the nonlinearities of the climate system, and constitutes an additional measure of uncertainty with DD. © 2019, The Author(s).
英文关键词	CORDEX; CRCM5; Dynamical downscaling; North America; Regional climate modelling; SST bias correction
语种	英语
scopus关键词	atmospheric correction; boundary condition; climate change; climate modeling; general circulation model; regional climate; sea surface temperature; North America
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/146185
作者单位	Centre ESCER (Étude et la Simulation du Climat à l’Échelle Régionale), Département des sciences de la Terre et de l’atmosphère, Université du Québec à Montréal (UQAM), C.P. 8888, Succ. Centre-ville, Montreal, QC H3C 3P8, Canada
推荐引用方式 GB/T 7714	Hernández-Díaz L.,Nikiéma O.,Laprise R.,et al. Effect of empirical correction of sea-surface temperature biases on the CRCM5-simulated climate and projected climate changes over North America[J],2019,53(2020-01-02).
APA	Hernández-Díaz L.,Nikiéma O.,Laprise R.,Winger K.,&Dandoy S..(2019).Effect of empirical correction of sea-surface temperature biases on the CRCM5-simulated climate and projected climate changes over North America.Climate Dynamics,53(2020-01-02).
MLA	Hernández-Díaz L.,et al."Effect of empirical correction of sea-surface temperature biases on the CRCM5-simulated climate and projected climate changes over North America".Climate Dynamics 53.2020-01-02(2019).