利用经验正交函数数据插值法重构东中国海叶绿素a质量浓度场

利用经验正交函数数据插值法(Data INterpolating Empirical Orthogonal Functions)重构由MODIS-Aqua卫星提供的三级产品叶绿素a质量浓度,得到了从2003—2009年东中国海叶绿素a质量浓度的月平均场。东中国海近岸叶绿素a质量浓度7 a平均值明显高于外海。对叶绿素a质量浓度季节平均场进行分析研究表明,东中国海叶绿素a质量浓度主要受长江径流、海表水温和季风的影响。对叶绿素a质量浓度异常场进行EOF分析表明,第一模态方差贡献为37.8％,空间分布显示,在长江口东北部出现叶绿素a质量浓度异常高值区,时间变化以半年和半年以下周期为主;第二模态方差贡献为21.4％,空间分布显示,在长江口东部出现叶绿素a质量浓度异常高值区,时间系数主要表现为年际变化。

Reconstruction of chlorophyll a mass concentration in the East China Sea using Data INterpolating Empirical Orthogonal Functions

Data INterpolating Empirical Orthogonal Functions (DINEOF) were used to reconstruct the chlorophyll a mass concentration from the three-level product of the MODIS-Aqua satellite. The monthly chlorophyll a mass concentration from 2003 to 2009 was obtained. The analysis on the filled data showed that the 7-years averaged chlorophyll a mass concentration in the nearshore is significantly larger than the one in the offshore. The seasonal chlorophyll-a mass concentration supports the conclusion that chlorophyll a in the East China Sea is mainly controlled by runoff of Changjiang River, sea surface temperature and monsoon. Furthermore, Empirical Orthogonal Functions were imposed on the chlorophyll a anomaly, and results showed that the first mode contribution is 37.8%, also the spatial pattern shows large value in the north-east of Changjiang River, and the corresponding temporal period is dominated by half a year or less. Meanwhile, the second mode contribution is 21.4%, the spatial pattern presents high value in the east of Changjiang River, and its temporal coefficient shows the inter-annual variance.