气候变化领域集成服务门户(CCPortal): The critical role of non-normality in partitioning tropical and extratropical contributions to PNA growth

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DOI	10.1175/JCLI-D-19-0555.1
	The critical role of non-normality in partitioning tropical and extratropical contributions to PNA growth
	Henderson S.A.; Vimont D.J.; Newman M.
发表日期	2020
ISSN	0894-8755
起始页码	6273
结束页码	6295
卷号	33 期号:14
英文摘要	The Pacific-North American (PNA) teleconnection pattern has been linked both to tropical phenomena, including the Madden-Julian oscillation (MJO) and El Niño-Southern Oscillation (ENSO), and to internal extratropical processes, including interactions with the zonally varying basic state and synoptic eddies. Many questions remain, however, concerning how these various relationships act, both separately and together, to yield observed PNA variability. Using linear inverse modeling (LIM), this study finds that the development and amplification of PNA anomalies largely results from the interference of modes strongly coupled to sea surface temperatures (SST), such as ENSO, and modes internal to the atmosphere, including the MJO. These SST-coupled and ''internal atmospheric'' modes form subspaces that are not orthogonal, and PNA growth is shown to occur via non-normal interactions. An internal atmospheric space LIM is developed to examine growth beyond this interference by removing the SST-coupled modes, effectively removing ENSO and retaining MJO variability. Optimal PNA growth in the internal atmospheric space LIM is driven by MJO heating, particularly over the Indian Ocean, and a retrograding northeast Pacific streamfunction anomaly. Additionally, the individual contributions of tropical heating and the extratropical circulation on PNA growth are investigated. The non-normal PNA growth is an important result, demonstrating the difficulty in partitioning PNA variance into contributions from different phenomena. This cautionary result is likely applicable to many geophysical phenomena and should be considered in attribution studies. © 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	Atmospheric pressure; Inverse problems; Oceanography; Surface waters; Tropics; Extratropical circulation; Geophysical phenomena; Linear inverse models; Madden-Julian oscillation; Sea surface temperature (SST); Southern oscillation; Streamfunctions; Teleconnection patterns; Climatology; air-sea interaction; anomaly; eddy; El Nino-Southern Oscillation; extratropical environment; Madden-Julian oscillation; numerical model; sea surface temperature; teleconnection; tropical environment; 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/171210
作者单位	Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI, United States; Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, United States; Physical Sciences Laboratory, NOAA, Earth System Research Laboratories, Boulder, CO, United States
推荐引用方式 GB/T 7714	Henderson S.A.,Vimont D.J.,Newman M.. The critical role of non-normality in partitioning tropical and extratropical contributions to PNA growth[J],2020,33(14).
APA	Henderson S.A.,Vimont D.J.,&Newman M..(2020).The critical role of non-normality in partitioning tropical and extratropical contributions to PNA growth.Journal of Climate,33(14).
MLA	Henderson S.A.,et al."The critical role of non-normality in partitioning tropical and extratropical contributions to PNA growth".Journal of Climate 33.14(2020).