冬季浙闽沿岸水分布的短期变动与风的关系初探

Short-term Variability of the Distribution of Zhe-Min Coastal Water and Wind Forcing during Winter Monsoon in the Taiwan Strait

利用1999年7月至2003年5月期间的遥感数据,包括AVHRR海表层温度、QuikSCAT风场和风应力数据,在分析4年内月平均遥感温度场和风场特征与历年现场观测所获得的认识一致的基础上,选取2002年002-008天这一连续晴空的时段,尝试建立简单的沿岸冷水影响面积表征方法,初步探讨了冬季台湾海峡浙闽沿岸水分布的短期变动与风应力之间的关系。结果表明,风是决定冬季台湾海峡海表层温度逐日变动的关键因素,日平均SST与风应力的相关系数R2达到0·90。采用温度法(SST≤17℃)和温度空间距平法(≤-1℃)表征的浙闽沿岸水影响面积的变化趋势基本一致,而且影响面积的逐日变动与风应力显著相关,二者的相关系数R2分别达到0·90和0·91。

This paper has a primary look at the daily variation of coastal water distribution in relation to wintertime wind forcing in the Taiwan Strait. QuikSCAT wind data and AVHRR Sea Surface Temperature(SST) data during the period from July, 1999 to May, 2003 were used in this study. Monthly mean wind field and SST during this period were analyzed first. It was shown that this remote sensing dataset revealed similar temporal and spatial features of wind field and SST as people reported based on in situ investigation. Daily SST and wind forcing data during Jan. 2nd to the 8th, 2002 were thus further used to study the short-term temporal pattern of Zhe-Min Coastal Water and its relationship with wind forcing. Two simplified methods were attempted to estimate the area of Zhe-Min Coastal Water distributed. One used SST≤17℃ and the other used SSTA≤-1℃ as the criteria. It was demonstrated that wind was the key factor controlling the daily variation of SST in the Taiwan Strait. The area of Zhe-Min Coastal Water was highly correlated with wind stress, with its correlation coefficient(R2) reaching 0.90.