Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JAS-D-16-0291.1 |
Propagating Annular Modes: Empirical Orthogonal Functions, Principal Oscillation Patterns, and Time Scales | |
Sheshadri, Aditi1; Plumb, R. Alan2 | |
2017-05-01 | |
发表期刊 | JOURNAL OF THE ATMOSPHERIC SCIENCES
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ISSN | 0022-4928 |
EISSN | 1520-0469 |
出版年 | 2017 |
卷号 | 74期号:5 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | The two leading empirical orthogonal functions (EOFs) of zonal-mean zonal wind describe north-south fluctuations, and intensification and narrowing, respectively, of the midlatitude jet. Under certain circumstances, these two leading EOFs cannot be regarded as independent but are in fact manifestations of a single, coupled, underlying mode of the dynamical system describing the evolution in time of zonal wind anomalies. The true modes are revealed by the principal oscillation patterns (POPs). The leading mode and its associated eigenvalue are complex, its structure involves at least two EOFs, and it describes poleward (or equatorward) propagation of zonal-mean zonal wind anomalies. In this propagating regime, the principal component (PC) time series associated with the two leading EOFs decay nonexponentially, and the response of the system to external forcing in a given EOF does not depend solely on the PC decorrelation time nor on the projection of the forcing onto that EOF. These considerations are illustrated using results from an idealized dynamical core model. Results from Southern Hemisphere ERA-Interim data are partly consistent with the behavior of the model's propagating regime. Among other things, these results imply that the time scale that determines the sensitivity of a model to external forcing might be different from the decorrelation time of the leading PC and involves both the rate of decay of the dynamical mode and the period associated with propagation. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000400730900001 |
WOS关键词 | FLUCTUATION-DISSIPATION THEOREM ; GENERAL-CIRCULATION MODEL ; SOUTHERN-HEMISPHERE CIRCULATION ; ZONAL FLOW INTERACTIONS ; EXTRATROPICAL CIRCULATION ; POLEWARD PROPAGATION ; CLIMATE RESPONSE ; EDDY FEEDBACKS ; PART II ; VARIABILITY |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/29314 |
专题 | 地球科学 |
作者单位 | 1.Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA; 2.MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA |
推荐引用方式 GB/T 7714 | Sheshadri, Aditi,Plumb, R. Alan. Propagating Annular Modes: Empirical Orthogonal Functions, Principal Oscillation Patterns, and Time Scales[J]. JOURNAL OF THE ATMOSPHERIC SCIENCES,2017,74(5). |
APA | Sheshadri, Aditi,&Plumb, R. Alan.(2017).Propagating Annular Modes: Empirical Orthogonal Functions, Principal Oscillation Patterns, and Time Scales.JOURNAL OF THE ATMOSPHERIC SCIENCES,74(5). |
MLA | Sheshadri, Aditi,et al."Propagating Annular Modes: Empirical Orthogonal Functions, Principal Oscillation Patterns, and Time Scales".JOURNAL OF THE ATMOSPHERIC SCIENCES 74.5(2017). |
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