气候变化领域集成服务门户(CCPortal): Spatiotemporal Variability of the Southern Annular Mode and its Influence on Antarctic Surface Temperatures

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DOI	10.1029/2020JD033818
	Spatiotemporal Variability of the Southern Annular Mode and its Influence on Antarctic Surface Temperatures
	Wachter P.; Beck C.; Philipp A.; Höppner K.; Jacobeit J.
发表日期	2020
ISSN	2169897X
卷号	125 期号:23
英文摘要	The Southern Annular Mode (SAM) is the predominant atmospheric variability mode in the Southern Hemisphere. In this paper, we present the spatial variability results of the SAM pattern for the period 1979–2018. The SAM-intrinsic pattern variability analysis is based on the principal component analysis (PCA), which is carried out for the ERA-Interim 500 hPa geopotential height (GPH) data set. A spatiotemporally resolved data set of SAM pattern maps (PCA loadings) is derived by projecting monthly shifted sub-sequences of SAM index values (PCA scores) on the corresponding GPH anomalies. The dominant SAM structure within single pattern fields is mapped automatically and can be interpreted as the Southern Hemisphere polar front. This data set allows an analysis of the geographical positions of the characteristic circumpolar SAM structure over four decades and shows considerable variability over space and time. Five different states of SAM patterns, which are associated with characteristic circulation anomalies during different phases of the study period, are identified. Station-based Antarctic temperature anomalies can be synoptically explained by these circulation anomalies. The overall latitudinal trend of the SAM pattern indicates an intensification of the meridional structure, especially over the East Antarctic Southern Ocean. Furthermore, we show that the SAM pattern variability is significantly correlated with the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation. Composites of 500 hPa GPH anomalies during the positive and negative phases of the respective indices indicate teleconnections with Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation, and this can explain latitudinal trends of the SAM pattern. ©2020. The Authors.
英文关键词	AMO; Antarctic circulation variability; Antarctic station temperature; PDO; SAM pattern variability; Southern Annular Mode
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/185609
作者单位	German Remote Sensing Data Center (DFD), German Aerospace Center (DLR), Wessling, Germany; Institute of Geography, Augsburg University, Augsburg, Germany; Institute Development-Space Research and Technology (VO-IR), German Aerospace Center (DLR), Köln, Germany
推荐引用方式 GB/T 7714	Wachter P.,Beck C.,Philipp A.,et al. Spatiotemporal Variability of the Southern Annular Mode and its Influence on Antarctic Surface Temperatures[J],2020,125(23).
APA	Wachter P.,Beck C.,Philipp A.,Höppner K.,&Jacobeit J..(2020).Spatiotemporal Variability of the Southern Annular Mode and its Influence on Antarctic Surface Temperatures.Journal of Geophysical Research: Atmospheres,125(23).
MLA	Wachter P.,et al."Spatiotemporal Variability of the Southern Annular Mode and its Influence on Antarctic Surface Temperatures".Journal of Geophysical Research: Atmospheres 125.23(2020).