The aim of this study was to assess the effects of El Niño and the Southern Oscillation (ENSO) on the temperature in southern Vietnam (TSV) and to establish a new ENSO index for the study area (named southern Vietnam Enso Index, VEI). Data used in this study included TSV, sea surface temperature (SST) in Niño regions, sea level pressure (SLP) at Tahiti and Darwin, and ENSO indices. The results showed that, among all ENSO indices, the oceanic Niño Index (ONI) and Japan Meteorological Agency ENSO index (JEI) gave a better correlation with TSV, but their correlation coefficients (R) were relatively low. That may suggest that these indices could be used with low efficiency for climate monitoring and prediction. The VEI was built based on the pair of SST in Niño 3.4 and Niño.West, which gained a higher correlation coefficient with the temperature in southern Vietnam in comparison with other ENSO indices. The lag time between VEI and TSV was about 5 months, which was one month longer than the one between ONI and TSV. Moreover, analyzing the temperature difference between the warm and cold phases also indicated that using VEI led to a higher contrast than using ONI. In brief, the newly established VEI could be more suitable for the study area.

这项研究的目的是评估厄尔尼诺现象和南方涛动（ENSO）对越南南部（TSV）温度的影响，并为研究区域建立新的ENSO指数（名为越南南部恩索指数，VEI）。这项研究中使用的数据包括TSV，尼诺地区的海表温度（SST），大溪地和达尔文的海平面压力（SLP）以及ENSO指数。结果表明，在所有ENSO指数中，海洋Niño指数（ONI）和日本气象厅ENSO指数（JEI）与TSV相关性更好，但它们的相关系数（R）相对较低。这可能表明这些指数可能无法有效地用于气候监测和预测。VEI是基于Niño3.4和Niño.West的一对SST构建的。与其他ENSO指数相比，其与越南南部温度的相关系数更高。VEI和TSV之间的滞后时间约为5个月，比ONI和TSV之间的滞后时间长一个月。此外，分析热相和冷相之间的温差还表明，使用VEI会比使用ONI产生更高的对比度。简而言之，新成立的VEI可能更适合研究领域。