ENSO对黑潮海区风应力异常影响的初步探讨

Relationship between Evolution of Wind Stress Anomalies in the Kuroshio Region and ENSO

利用近50a黑潮海区风应力场与Nino3区海温指数序列进行相关分析后发现,ENSO对黑潮海区经向风应力影响的"关键时段"为秋、冬季至次年初夏时期,对纬向风应力影响的"关键时段"为冬季至次年春季。黑潮海区风应力距平场与赤道中东太平洋SSTA场的扩展SVD分析及相应的合成分析揭示了ENSO期间黑潮海区风应力异常结构的演变:秋季,中国的东海、琉球群岛附近海域首先出现南风应力异常;冬季,吕宋岛以北、台湾以东的海域出现西南风应力异常,其影响范围和强度在次年2月前后达到最强,其后迅速减弱,至5月,风应力异常基本消失。赤道中东太平洋SSTA对黑潮海区经向风应力异常的影响范围较大,强度更显著。

Correlation analyses between the wind stress anomalies in the Kuroshio region and the Nino3 SST index series of nearly 50 years show that the 'key period' when ENSO affects the meridional wind stress anomalies in the Kuroshio region is autumn/winter to next spring,and that for the zonal wind stress anomalies is winter to next spring.The results of extended SVD analyses between wind stress anomalies and SSTA,and composite analyses reveal the evolution of structure of wind stress anomalies in the Kuroshio region during ENSO.In the autumn of ENSO year,the southern wind stress anomalies appear first over the East Sea and Ryukyu gunto,and the southeast wind stress strengthens at the north of Luzon and the east of Taiwan in winter.The range and intensity of anomalies become maximum in the next February,and then weaken rapidly and disappear in the next May.The range and the intensity of meridional wind stress anomalies affected by the SSTA are even more larger and stronger respectively.