气候变化领域集成服务门户(CCPortal): Persistent Model Biases in the CMIP6 Representation of Stratospheric Polar Vortex Variability

CCPortal

DOI	10.1029/2021JD034759
	Persistent Model Biases in the CMIP6 Representation of Stratospheric Polar Vortex Variability
	Hall R.J.; Mitchell D.M.; Seviour W.J.M.; Wright C.J.
发表日期	2021
ISSN	2169897X
卷号	126 期号:12
英文摘要	Sudden stratospheric warmings (SSWs) can have major impact on surface wintertime weather, especially at mid-high latitudes. We do not yet have a complete understanding of why some of these events influence our weather more than others, but one factor may be the dynamical nature of the SSW; whether it involves a split or a displacement of the polar vortex, and one way to explore this is through comprehensive climate models. Here, we analyze the stratospheric dynamics of SSWs within models from the sixth Coupled Model Intercomparison Project (CMIP6). All CMIP6 models simulate SSWs to some degree, although we find a persistent bias in the relative underrepresentation of split vortex events. When comparing with CMIP5 models, large biases persist despite significant model improvements in resolution and in representing atmospheric processes. We show that the simulated displacement frequency is strongly related to climatological lower stratospheric eddy heat flux. The split frequency, on the other hand, is not related to lower stratospheric eddy heat flux, but is strongly related to both the vortex geometry (aspect ratio) and lower stratospheric zonal winds. This suggests that those models with a large positive bias in zonal winds may inhibit the propagation of zonal wavenumber 2 planetary waves from the troposphere, which are associated with split events. Our results suggest how future model development may address these longstanding biases. © 2021. The Authors.
英文关键词	CMIP6; displacements; model bias; splits; stratospheric polar vortex; sudden stratospheric warming
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185134
作者单位	School of Geographical Sciences and Cabot Institute for the Environment, University of Bristol, Bristol, United Kingdom; Global Systems Institute and Department of Mathematics, University of Exeter, Exeter, United Kingdom; Centre for Space, Atmospheric and Oceanic Science, University of Bath, Bath, United Kingdom
推荐引用方式 GB/T 7714	Hall R.J.,Mitchell D.M.,Seviour W.J.M.,et al. Persistent Model Biases in the CMIP6 Representation of Stratospheric Polar Vortex Variability[J],2021,126(12).
APA	Hall R.J.,Mitchell D.M.,Seviour W.J.M.,&Wright C.J..(2021).Persistent Model Biases in the CMIP6 Representation of Stratospheric Polar Vortex Variability.Journal of Geophysical Research: Atmospheres,126(12).
MLA	Hall R.J.,et al."Persistent Model Biases in the CMIP6 Representation of Stratospheric Polar Vortex Variability".Journal of Geophysical Research: Atmospheres 126.12(2021).