DOI: 10.1007/s00382-015-2550-0
Scopus记录号: 2-s2.0-84947487249
论文题名: Two key parameters for the El Niño continuum: zonal wind anomalies and Western Pacific subsurface potential temperature
作者: Lai A.W.-C. ; Herzog M. ; Graf H.-F.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 45, 期: 2017-11-12 起始页码: 3461
结束页码: 3480
语种: 英语
英文关键词: Central Pacific El Niño
; El Niño continuum
; Oceanic potential temperature
; Thermocline discharge–recharge state
; Zonal wind anomalies
英文摘要: Different types of El Niño (EN) events have recently been discussed. Based on NCEP–NOAA reanalysis data this analysis explores a number of key parameters that cause a range of EN types over the period 1980–2013. EN events are divided into three types depending on the spatial and temporal evolution of the sea surface temperature anomalies (SSTA): Central Pacific (CPEN), Eastern Pacific (EPEN), and Hybrid (HBEN). We find that EN is a continuous spectrum of events with CPEN and EPEN as the end members. This spectrum mainly depends on two key parameters: the 130°E–160°E Western Pacific 5–250 m subsurface oceanic potential temperature anomaly about 1 year before the EN peak (typically January and February), and the 140°E–160°W cumulative zonal wind anomaly (ZWA) between onset and peak of the EN event. Using these two parameters, about 70 % of the total variance of the maximum SSTA realised in different Niño regions can already be explained up to 6 months before the maximum SSTA occurs. This offers a rather simple potential for ENSO prediction. A necessary condition for the evolution of an EPEN, the Western Pacific is in the recharged state. Strong and sustained westerly wind anomalies in Western Pacific can then trigger a Kelvin wave propagating to the eastern Pacific. Both parameters, potential temperature and zonal wind anomaly, constructively interfere. For a CPEN, these parameters are much less important. Kelvin wave propagation is not involved in the evolution of the event. Instead, the Central Pacific warming is caused locally by a zonal advection feedback and local air–sea interaction as already demonstrated in previous studies. The HBEN occurs when both parameters interfere in different ways: (1) Western Pacific is weakly charged, but strong westerly ZWA are observed that reduce the equatorial upwelling in the Central Pacific while the triggered Kelvin wave is too weak to have a significant effect; (2) Western Pacific is strongly charged but only weak westerly ZWA develop, so that the resulting Kelvin wave cannot fully extend into the eastern-most Pacific. © 2015, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53930
Appears in Collections: 过去全球变化的重建
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作者单位: Centre for Atmospheric Science, University of Cambridge, Downing Place, Cambridge, United Kingdom
Recommended Citation:
Lai A.W.-C.,Herzog M.,Graf H.-F.. Two key parameters for the El Niño continuum: zonal wind anomalies and Western Pacific subsurface potential temperature[J]. Climate Dynamics,2015-01-01,45(2017-11-12)