【摘要】 利用1951—2016年HadISST逐月海表温度(Sea Surface Temperature,SST)资料,NCEP/NCAR再分析资料以及1958—2016年美国伍兹霍尔海洋研究所(Woods Hole Oceanographic Institution,WHOI)提供的OAFlux数据集,运用经验正交函数分解(Empirical Orthogonal Function,EOF)和偏相关分析等统计方法,研究了春季北大西洋海温异常的主要特征及其与春季NAO和前期冬季ENSO联系。结果表明:春季北大西洋海温异常EOF的第一模态是自北而南出现的三极结构的海温距平型,其方差贡献率为35.7%。春季北大西洋三极型海温异常的形成主要受到春季NAO主导作用,还受到前期冬季热带中东太平洋海温异常的影响。消除前期冬季Niňo3.4的影响后,春季北大西洋三极型海温异常指数与同期北大西洋涛动(North Atlantic Oscillation,NAO)指数的偏相关系数分别为0.50,通过了99%置信度水平的显著性检验。消除春季NAO的影响后,春季北大西洋三极型海温异常指数与前期冬季Niňo3.4指数的偏相关系数为-0.26,通过了95%信度水平的显著性检验。春季NAO正(负)位相引起的海表风场和海表湍流热通量的异常,进而激发出正(负)位相的北大西洋三极型海温异常。前期冬季ENSO事件可以引起春季大气环流异常和热带外海温异常,进而调制春季NAO对北大西洋三极型海温异常的影响。更多还原

【Abstract】 Based on the data form the monthly Sea Surface Temperature(SST) data of HadISST from 1951 to 2016, NCEP/NCAR reanalysis and Woods Hole Oceanographic Institution(WHOI) form 1958—2016, and statistical methods such as Empirical Orthogonal Function(EOF) and partial correlation analysis, the main characteristics of the North Atlantic Sea Surface Temperature Anomaly(SSTA) in spring and their association with the spring NAO and previously winter ENSO are studied. The results show that the first mode of EOF in spring exhibits a meridional tri-polar pattern, which revealed 35.7% variance. The spring tri-polar pattern SSTA over the North Atlantic is mainly affected by the spring NAO and the central and eastern tropical Pacific SSTA in the previous winter. After eliminating the influence of the previous winter Niňo3.4, the partial correlation coefficient between the North Atlantic Tri-pole(NAT) mode index and the North Atlantic Oscillation(NAO) index is 0.50, which passes the 99% confidence level significance test. After eliminating the effects of spring NAO, the partial correlation coefficient between spring NAT index and the previous winter Niňo3.4 index is-0.26, which passes the 95% confidence level significance test. Associated with the sea surface wind and sea surface turbulent heat flux anomalies in North Atlantic, the positive(negative) NAO in spring leads to the positive(negative) NAT SSTA. The previous winter ENSO events can cause atmospheric circulation anomaly and extratropical SST anomaly in spring, which in turn modulate the influence of spring NAO on the North Atlantic tri-polar pattern SSTA in spring.更多还原