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DOI	10.1175/JCLI-D-19-0904.1
	Modes of atmospheric circulation variability in the northern extratropics: A comparison of five reanalyses
	Hyncica M.; Huth R.
发表日期	2020
ISSN	0894-8755
起始页码	10707
结束页码	10726
卷号	33 期号:24
英文摘要	Modes of low-frequency circulation variability in the Northern Hemisphere extratropics are compared between five reanalyses. Circulation modes are detected by rotated principal component analysis (PCA) of monthly mean 500-hPa geopotential heights between 1957 and 2002, separately for individual seasons. The quantification of differences between reanalyses is based on the percentage of grid points (approximately corresponding to the percentage of area) where the spatial representations of a mode (loadings) significantly differ between reanalyses. The differences between surface-input reanalyses (20CRv2c, ERA-20C) and full-input reanalyses (NCEP-1, ERA-40, JRA-55) are larger than differences within the reanalysis groups in all seasons except for autumn. The causes of the differences are of two kinds. First, the differences may be inherent to PCA: namely, the spatial structure of the modes may be sensitive to the number of components rotated. This concerns only a few modes. Second, the differences may reflect real correlation structures in reanalysis data. We demonstrate that the differences concentrate in three or fewer modes in each season. The reanalysis most different from the rest is 20CRv2c, with the differences concentrating over the southern half of Asia and in the subtropical belt over the Pacific and adjacent southwestern North America. The 20CRv2c reanalysis disagrees from other reanalyses there predominantly before the 1980s, which points to the impact of insufficient amount of assimilated observations. On the contrary, ERA-20C exhibits a higher agreement with full-input reanalyses, which is why we recommend it for studies of atmospheric circulation over the entire twentieth century. Ó 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Climate models; American meteorological societies; Atmospheric circulation; Atmospheric circulation variability; Copyright informations; Correlation structure; Geo-potential heights; Rotated principal components; Spatial representations; Climatology; atmospheric circulation; comparative study; extratropical environment; geopotential; Northern Hemisphere; principal component analysis; quantitative analysis; teleconnection; Asia; North America; Pacific Ocean
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171049
作者单位	Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic; Czech Hydrometeorological Institute, Ústí nad Labem, Czech Republic; Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
推荐引用方式 GB/T 7714	Hyncica M.,Huth R.. Modes of atmospheric circulation variability in the northern extratropics: A comparison of five reanalyses[J],2020,33(24).
APA	Hyncica M.,&Huth R..(2020).Modes of atmospheric circulation variability in the northern extratropics: A comparison of five reanalyses.Journal of Climate,33(24).
MLA	Hyncica M.,et al."Modes of atmospheric circulation variability in the northern extratropics: A comparison of five reanalyses".Journal of Climate 33.24(2020).