The spatio-temporal variability of the chlorophyll-a (chl-a) concentration in the East Sea (Japan Sea) (EJS) was investigated using Moderate Resolution Imaging Spectroradiometer (MODIS) data over 13 years from 2003 to 2015 to understand the impact of physical environmental changes on low-trophic level marine ecosystems. The chl-a images were composited to produce gridded monthly chl-a images using a weighted average method after applying a speckle removal algorithm to each path image. Missing pixels without any satellite observations because of cloud coverage were objectively filled using three-dimensional optimal interpolation. The first empirical orthogonal function (EOF) mode of the monthly chl-a images, accounting for 14% of the total variance, showed higher eigenvectors values in the eastern part of the EJS and distinct annual peaks each spring. The amplitudes of the first EOF mode, despite the dominant year-to-year variations in chl-a, tended to increase during spring over time. The recent 13-year trend of chl-a showed differences between the southwestern part and the northeastern part of the EJS, and this difference clearly appeared in the monthly trend maps for March and April. The eastern coast of Korea showed a highly positive trend during summer, particularly during August. The changes in chl-a over the decade were related to the physical environmental changes in sea surface wind, mixed layer depth, and stratification of upper sea water in the EJS.

中文翻译：

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2003年至2015年卫星观测的叶绿素a浓度变化及其与东海（日本海）物理环境变化的关系

使用中分辨率成像光谱仪（MODIS）数据调查了2003年至2015年这13年间东海（日本海）（EJS）中叶绿素a（chl- a）浓度的时空变化，以了解低营养水平海洋生态系统的自然环境变化。所述chl-一个图像进行合成以产生每月网格chl-一个施加斑点去除算法，以每个路径图像之后使用加权平均法的图像。使用三维最优插值客观地填充了由于云覆盖而没有任何卫星观测的丢失像素。每月chl- a的第一个经验正交函数（EOF）模式占总方差14％的图像在EJS的东部显示了较高的特征向量值，并且每年春季都有明显的年峰值。第一EOF模式，振幅尽管chl-占主导地位的一年到一年的变化一个，往往随着时间的推移春运期间增加。最近chl-的13年趋势一西南部和EJS东北部，这种差异之间的差异表现显然出现了月度走势映射三，四月份。夏季，特别是八月份，韩国东部沿海地区表现出高度积极的趋势。在chl-变化一 在过去的十年中，EJS与海面风，混合层深度和上层海水分层的物理环境变化有关。