Upwelling induced acidification and bloom induced deacidification over the southwestern part of the East Sea

Abstract

Through idealized numerical experiments in which ocean circulation, carbon cycle and simple ecology are combined (Fennel et al 2006), we investigated the effect of coastal upwelling on the biogeochemical cycle over the southwestern part of the East Sea. As well-known when southwesterly winds parallel to the coast line for more than several days upwelling that brings cold and nutrient rich subsurface water to the surface occurs. Due to the upwelled nutrient phytoplankton bloom occurs in about a week after the upwelling has initiated. Initially the upwelling lowers the pH of the surface water, but as the bloom progresses the concentration of dissolved inorganic carbon (DIC) becomes lower due to photosynthesis and pH becomes higher to a value higher than that before the upwelling. This deacidification, however, is limited to the surface layer. These model results are consistent with observational results obtained over the study area in May 2011.the East Sea. As well-known when southwesterly winds parallel to the coast line for more than several days upwelling that brings cold and nutrient rich subsurface water to the surface occurs. Due to the upwelled nutrient phytoplankton bloom occurs in about a week after the upwelling has initiated. Initially the upwelling lowers the pH of the surface water, but as the bloom progresses the concentration of dissolved inorganic carbon (DIC) becomes lower due to photosynthesis and pH becomes higher to a value higher than that before the upwelling. This deacidification, however, is limited to the surface layer. These model results are consistent with observational results obtained over the study area in May 2011.