Biophysical interactions in the subsurface Chlorophyll-a maximum layer in the East China Sea

Abstract

The data observed in July and/or August 2003-2007 show that the depth of SCM layer is shallower toward the west and it is connected to high Chlorophyll-a concentration near the sea surface in the Changjiang bank. The results of numerical simulation support that the lateral dependence of the SCM depth is a common summertime feature in the region. The yearly values of vertical gradients of nutrients within the SCM layer are quantitatively similar, though large annual variation exists in their vertical distributions. The turbulent energy dissipation rates show high within the thermocline, with typical value of O(10-7) and occasionally close to 10-6 Wkg-1. Corresponding vertical eddy diffusivities reach to 10-2 m2s-1. Such high values of dissipation rate and vertical diffusivity match with the SCM.mulation support that the lateral dependence of the SCM depth is a common summertime feature in the region. The yearly values of vertical gradients of nutrients within the SCM layer are quantitatively similar, though large annual variation exists in their vertical distributions. The turbulent energy dissipation rates show high within the thermocline, with typical value of O(10-7) and occasionally close to 10-6 Wkg-1. Corresponding vertical eddy diffusivities reach to 10-2 m2s-1. Such high values of dissipation rate and vertical diffusivity match with the SCM.