On the Shortening of the Lead Time of Ocean Warm Water Volume to ENSO SST Since 2000.
On the Shortening of the Lead Time of Ocean Warm Water Volume to ENSO SST Since 2000.
复制标题
DOI：
10.1038/s41598-017-04566-z
复制
发表时间：
2017-06-27
影响因子：
4.6
通讯作者：
Wang X
中科院分区：
文献类型：
--
作者：
Hu ZZ;Kumar A;Zhu J;Huang B;Tseng YH;Wang X
记录了2000年后与赤道太平洋暖水量（WWV）变率沿着和厄尔尼诺-南方涛动（ENSO）变率之间的前置时间缩短有关的可能因素。结果表明，提前时间的缩短是由于WWV和ENSO的频率增加。在1979- 1999年期间，Niño3.4和WWV指数的主要频率均为1.5-3.5年。相比之下，在2000- 2016年期间，这两个指数的频谱相对平坦，更接近于白色噪声过程，Niño3.4指数的相对最大值为1.5-2.0年，WWV指数为0.8-1.3年。ENSO和WWV的频率变化与Bjerknes反馈区的向西移有关。结果与前人的观点一致，即海气耦合区的向西移将导致ENSO频率的增加，因为相应的纬向平流反馈减小了耦合不稳定的周期和增长，从而有利于更频繁和更弱的厄尔尼诺事件。
The possible factors associated with the shortening of lead time between ocean warm water volume (WWV) variability along the equatorial Pacific and El Niño–Southern Oscillation (ENSO) variability after 2000 are documented. It is shown that the shortening of lead time is due to frequency increases of both WWV and ENSO. During 1979–99 the dominant frequencies were 1.5–3.5 years for both the Niño3.4 and WWV indices. In contrast, during 2000–16, both indices had a relatively flatter spectrum and were closer to a white noise process with a relative maximum at 1.5–2.0 years for the Niño3.4 index and 0.8–1.3 years for the WWV index. The frequency change of ENSO and WWV were linked to a westward shift of the Bjerknes feedback region. The results here are consistent with previous argument that the westward shift of the air-sea coupling region will cause an increase of ENSO frequency, as the corresponding zonal advection feedback reduces the period and growth of coupled instability, thus favoring more frequent and weak El Niño events.