Primary productivity and its inter-annual variability in the East Sea, 1998-2007

Abstract

We investigated the interannual variability of primary production in the East Sea for the 10-year period from January 1998 to December 2007. Primary production was calculated from satellite ocean color data using a local primary production algorithm for the East Sea. To identify the spatio-temporal patterns of primary production, empirical orthogonal function analysis was applied. Based on this, the East Sea was classified into several sub-regions using K-means clustering method. The primary productivity of each sub-region showed characteristic seasonal and interannual variability. The time series of primary productivity of each sub-region were compared with physical factors (wind stress, mixed layer depth, photosynthetic available radiation and volume transport of the Tsushima Warm Current) and climate indices, such as the Multivariate ENSO Index, the Siberian High Index and the East Asian Winter Monsoon Index. The seasonal and annual primary productivity in each sub-region show different relationships with physical forcing and climate indices. Here we discuss how the variability of primary production in the East Sea is linked to local and non-local forcing.algorithm for the East Sea. To identify the spatio-temporal patterns of primary production, empirical orthogonal function analysis was applied. Based on this, the East Sea was classified into several sub-regions using K-means clustering method. The primary productivity of each sub-region showed characteristic seasonal and interannual variability. The time series of primary productivity of each sub-region were compared with physical factors (wind stress, mixed layer depth, photosynthetic available radiation and volume transport of the Tsushima Warm Current) and climate indices, such as the Multivariate ENSO Index, the Siberian High Index and the East Asian Winter Monsoon Index. The seasonal and annual primary productivity in each sub-region show different relationships with physical forcing and climate indices. Here we discuss how the variability of primary production in the East Sea is linked to local and non-local forcing.