동중국해 여름철 연직혼합

Abstract

Relatively high chlorophyll-a concentrations have been frequently observed within the thermocline in the northern East China Sea (ESC) during summer. One of the possible mechanisms to support high chlorophyll-a is vertical mixing which enhances nutrients supply into the thermocline from deep waters. Based on microstructure measurements in the northern ESC in Augusts of 2005 and 2006, within the thermocline, we identified elevated turbulence dissipation rates and the associated vertical eddy diffusivities that are higher by an order of magnitude than the background values. The strong vertical mixing is possibly due to breaking of internal waves that often occur in the northern ESC during summer. This suggests that vertical mixing may play an important role in nutrient budget and thus chlorophyll-a concentration in the continental shelf in the northern ECS during summer.