ENSO Impact on Kelvin Waves and Associated Tropical Convection
ENSO Impact on Kelvin Waves and Associated Tropical Convection
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DOI：
10.1175/jas-d-13-081.1
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发表时间：
2013-10
影响因子：
3.1
通讯作者：
Gui‐Ying Yang;B. Hoskins
中科院分区：
文献类型：
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作者：
Gui‐Ying Yang;B. Hoskins
本文利用ECMWF再分析资料、NOAA出射长波辐射资料和前人研究中介绍的分析技术，研究了厄尔尼诺-南方涛动（ENSO）对大气Kelvin波和相关热带对流的影响。结果表明，ENSO的位相对赤道中东太平洋的Kelvin波及其相关对流有重要影响。厄尔尼诺（拉尼娜）事件增强（抑制）对流层上部Kelvin波和相关对流的变率，其影响机制是通过ENSO相关热力条件和环境气流的变化。在厄尔尼诺年，由于赤道中东太平洋海温的增加，东向移动的对流，这主要是与开尔文波，在该地区的变率增强。此外，在厄尔尼诺年，由于赤道东太平洋西风导管在对流层上部的减弱，
AbstractThe impact of El Nino–Southern Oscillation (ENSO) on atmospheric Kelvin waves and associated tropical convection is investigated using the ECMWF Re-Analysis, NOAA outgoing longwave radiation (OLR), and the analysis technique introduced in a previous study. It is found that the phase of ENSO has a substantial impact on Kelvin waves and associated convection over the equatorial central-eastern Pacific. El Nino (La Nina) events enhance (suppress) variability of the upper-tropospheric Kelvin wave and the associated convection there, in both extended boreal winter and summer.The mechanism of the impact is through changes in the ENSO-related thermal conditions and the ambient flow. In El Nino years, because of SST increase in the equatorial central-eastern Pacific, variability of eastward-moving convection, which is mainly associated with Kelvin waves, intensifies in the region. In addition, owing to the weakening of the equatorial eastern Pacific westerly duct in the upper troposphere in El Nino years,...