The Nature and Causes for the Delayed Atmospheric Response to El Niño
The Nature and Causes for the Delayed Atmospheric Response to El Niño
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DOI：
10.1175/1520-0442-16.9.1391
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发表时间：
2003-05
影响因子：
4.9
通讯作者：
Arun Kumar;M. Hoerling
中科院分区：
文献类型：
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作者：
Arun Kumar;M. Hoerling
与厄尔尼诺-南方涛动(ENSO)相关的大气现象中值得注意的是纬向平均热带热异常相对于赤道东太平洋海温(SSTs)的滞后。在1950-1999年期间，观测到的热带纬向平均200mb高度与Nino-3.4(5°N-5°S，120°-170°W)海温指数之间的最大相关出现在大气滞后1-3个月的时候，这与以往的许多研究一致。大气环流模式(GCM)模拟的结果证实并证实了这种观测滞后的稳健性。这项研究记录了大气响应延迟的另一个特征，即热带热异常在Nino-3.4 SST指数峰值之后几个季节的明显记忆或挥之不去。它的特点是纬向平均热带200毫巴高度响应的强度相对于该峰值具有很强的不对称性，为三倍。
Abstract Remarkable among the atmospheric phenomena associated with El Nino–Southern Oscillation (ENSO) is the lag in the zonal mean tropical thermal anomalies relative to equatorial east Pacific sea surface temperatures (SSTs). For the period 1950–99, the maximum correlation between observed zonal mean tropical 200-mb heights and a Nino-3.4 (5°N–5°S, 120°–170°W) SST index occurs when the atmosphere lags by 1–3 months, consistent with numerous previous studies. Results from atmospheric general circulation model (GCM) simulations forced by the monthly SST variations of the last half-century confirm and establish the robustness of this observed lag. An additional feature of the delay in atmospheric response that involves an apparent memory or lingering of the tropical thermal anomalies several seasons beyond the Nino-3.4 SST index peak is documented in this study. It is characterized by a strong asymmetry in the strength of the zonal mean tropical 200-mb height response relative to that peak, being threefol...