Surface Current in "Hotspot" Serves as a New and Effective Precursor for El Niño Prediction.
Surface Current in "Hotspot" Serves as a New and Effective Precursor for El Niño Prediction.
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“热点”地表海流成为厄尔尼诺预报新的有效前兆
DOI：
10.1038/s41598-017-00244-2
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发表时间：
2017-03-13
影响因子：
4.6
通讯作者：
Zhang RH
中科院分区：
文献类型：
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作者：
Wang J;Lu Y;Wang F;Zhang RH
厄尔尼诺和南方涛动（ENSO）是年际气候变率的最主要来源。与季节性相位锁定有关，厄尔尼诺/南方涛动对北方春季低持久性障碍的预测仍然是一个挑战。在这里，我们通过应用回归分析确定了表面电流变化影响7月Niño 3.4指数的短提前期预测的区域。与风应力旋度和海表温度分布有关的一个高度影响区位于日界线附近和南赤道流的南部边缘。在厄尔尼诺年期间，在确定的高影响区，向西的海流异常有利于西太平洋的温水积累。在拉尼娜年，情况正好相反。这一过程被视为厄尔尼诺/南方涛动发展的“目标射击”，为预测7月的厄尔尼诺3.4指数提供了有效的前兆，提前时间为2-4个月。在7月以后的几个月，基于表层流前兆的预报技巧优于基于暖水量和持续性的预报技巧。特别是，预测的基础上，表面电流前兆显示在所有年份的技能，而预测的基础上，其他前兆显示2002年后技能下降。
The El Niño and Southern Oscillation (ENSO) is the most prominent sources of inter-annual climate variability. Related to the seasonal phase-locking, ENSO’s prediction across the low-persistence barrier in the boreal spring remains a challenge. Here we identify regions where surface current variability influences the short-lead time predictions of the July Niño 3.4 index by applying a regression analysis. A highly influential region, related to the distribution of wind-stress curl and sea surface temperature, is located near the dateline and the southern edge of the South Equatorial Current. During El Niño years, a westward current anomaly in the identified high-influence region favours the accumulation of warm water in the western Pacific. The opposite occurs during La Niña years. This process is seen to serve as the “goal shot” for ENSO development, which provides an effective precursor for the prediction of the July Niño 3.4 index with a lead time of 2–4 months. The prediction skill based on surface current precursor beats that based on the warm water volume and persistence in the subsequent months after July. In particular, prediction based on surface current precursor shows skill in all years, while predictions based on other precursors show reduced skill after 2002.