自 2000 年以来，海洋暖水体积到厄尔尼诺-南方涛动（ENSO）海表温度的铅时缩短。

On the Shortening of the Lead Time of Ocean Warm Water Volume to ENSO SST Since 2000.

机构信息

Climate Prediction Center, NCEP/NWS/NOAA 5830 University Research Court, College Park, MD, 20740, USA.

Earth System Science Interdisciplinary Center, the University of Maryland, College Park, Maryland, 20740, USA.

出版信息

Sci Rep. 2017 Jun 27;7(1):4294. doi: 10.1038/s41598-017-04566-z.

DOI:10.1038/s41598-017-04566-z

PMID:28655896

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5487327/

Abstract

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.

摘要

记录了与 2000 年后赤道太平洋沿海水温体积（WWV）变化与厄尔尼诺-南方涛动（ENSO）变化之间的时间间隔缩短相关的可能因素。结果表明，时间间隔的缩短是由于 WWV 和 ENSO 的频率增加所致。在 1979-99 年期间，Niño3.4 和 WWV 指数的主导频率为 1.5-3.5 年。相比之下，在 2000-16 年期间，两个指数的谱都相对平坦，更接近白噪声过程，Niño3.4 指数的相对最大值为 1.5-2.0 年，WWV 指数的相对最大值为 0.8-1.3 年。ENSO 和 WWV 的频率变化与 Bjerknes 反馈区域的西向移动有关。这里的结果与先前的观点一致，即海气耦合区域的西向移动将导致 ENSO 频率增加，因为相应的纬向平流反馈减少了耦合不稳定性的周期和增长，从而有利于更频繁和较弱的厄尔尼诺事件。