Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JAS-D-16-0309.1 |
On the Tropical Atmospheric Signature of El Nino | |
Adames, Angel F.1; Wallace, John M.2 | |
2017-06-01 | |
发表期刊 | JOURNAL OF THE ATMOSPHERIC SCIENCES |
ISSN | 0022-4928 |
EISSN | 1520-0469 |
出版年 | 2017 |
卷号 | 74期号:6 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | The linear atmospheric signature of ENSO, obtained by regressing fields of geopotential height Z, wind, vertical velocity, and rainfall upon the Nino-3.4 sea surface temperature (SST) index, is partitioned into zonally symmetric and eddy components. The zonally symmetric component is thermally forced by the narrowing and intensification of the zonally averaged equatorial rain belt during El Nino and mechanically forced by the weakening of the upper-tropospheric equatorial stationary waves and their associated flux of wave activity. The eddy component of the ENSO signature is decomposed into barotropic (BT) and baroclinic (BC) contributions, the latter into first and second modal structures BC1 and BC2, separable functions of space (x, y), and pressure p, using eigenvector analysis. BC1 exhibits a nearly equatorially symmetric planetary wave structure comprising three dumbbell-shaped features suggestive of equatorial Rossby waves, with out-of-phase wind and geopotential height perturbations in the upper and lower troposphere. BC1 and BT exhibit coincident centers of action. In regions of the tropicswhere the flow in the climatological-mean stationary waves is cyclonic, BT reinforces BC1, and vice versa, in accordance with vorticity balance considerations. BC1 and BT dominate the eddy ENSO signature in the free atmosphere. Most of the residual is captured by BC2, which exhibits a shallow, convergent boundary layer signature forced by the weakening of the equatorial cold tongue in SST. The anomalous boundary layer convergence drives a deep convection signature whose upper-tropospheric outflow is an integral part of the BC1 contribution to the ENSO signature. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000403101200014 |
WOS关键词 | SURFACE-TEMPERATURE-GRADIENTS ; EQUATORIAL PLANETARY-WAVES ; PACIFIC SST ANOMALIES ; BOUNDARY-LAYER WINDS ; SOUTHERN-OSCILLATION ; 3-DIMENSIONAL STRUCTURE ; HADLEY-CELL ; MEAN FLOW ; CIRCULATION ; PRECIPITATION |
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/29313 |
专题 | 地球科学 |
作者单位 | 1.Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA; 2.Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA |
推荐引用方式 GB/T 7714 | Adames, Angel F.,Wallace, John M.. On the Tropical Atmospheric Signature of El Nino[J]. JOURNAL OF THE ATMOSPHERIC SCIENCES,2017,74(6). |
APA | Adames, Angel F.,&Wallace, John M..(2017).On the Tropical Atmospheric Signature of El Nino.JOURNAL OF THE ATMOSPHERIC SCIENCES,74(6). |
MLA | Adames, Angel F.,et al."On the Tropical Atmospheric Signature of El Nino".JOURNAL OF THE ATMOSPHERIC SCIENCES 74.6(2017). |
条目包含的文件 | 条目无相关文件。 |
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