Dominant plankton sizes in response to various upwelling events.

Off the east coast of Korean Peninsula is known as regions of high primary production. One of the most important processes for the high primary productivity in coastal areas is, strong upwelling events. In this research, we investigated long-term changes of upwelling intensity and furthermore, examined corresponding Chlorophyll-a concentration (CHL). For the study area, off the east coast of Korea is divided into 9 areas along the coastal lines at 0.25° of intervals from 35.25°N to 37.25°N. Specifically, research is conducted for long-term tendency of CHL off the east coast of Korea with focus on upwelling events using ‘Upwelling Age (UA)’. For obtaining UA, we used wind-vector from The European Centre for Medium-Range Weather Forecasts (ECMWF), ocean temperature and salinity profile data from Hybrid Coordinate Ocean Model (HYCOM), and bathymetry data from a 1 arc-minute global relief model of Earth’s surface that integrates land topography and ocean bathymetry (ETOPO1). The UA values are different along the regions of interests due to wind duration time, wind stress and continental shelf slopes, so do the dominant plankton size. In order to compare spatial changes of CHL, we used Moderate Resolution Imaging Spectroradiometer (MODIS) data. When UA is high, CHL is relatively higher and inversely sea surface temperature lower.