Variability of the inorganic carbon system in the mid-east coast of South Korea

Abstract

One of the ocean areas vulnerable to ocean acidification (OA) is coastal region which is frequently exposed to wind-driven upwelling. Thus we investigated temporal changes in the seawater carbonate system and the effect of upwelling on OA in Hupo, a central part of the east coast of South Korea. The estimated mean net sea-air carbon dioxide (CO2) flux was -1.99 ± 1.18 mol C yr-1, indicating that this region was a sink for atmospheric CO2. Our monthly data revealed that temporal changes in surface CO2 concentrations and calcium carbonate saturation states (Ω) were mainly governed by physical and biological processes. In particular, the wind-driven upwelling observed in July 2013 brought waters with high nutrients/CO2 and low pH/Ω to the surface and thus enhanced biological production in surface waters. OA in this coastal ecosystem is expected to be exacerbated by anthropogenic CO2 uptake and upwelling.n Hupo, a central part of the east coast of South Korea. The estimated mean net sea-air carbon dioxide (CO2) flux was -1.99 ± 1.18 mol C yr-1, indicating that this region was a sink for atmospheric CO2. Our monthly data revealed that temporal changes in surface CO2 concentrations and calcium carbonate saturation states (Ω) were mainly governed by physical and biological processes. In particular, the wind-driven upwelling observed in July 2013 brought waters with high nutrients/CO2 and low pH/Ω to the surface and thus enhanced biological production in surface waters. OA in this coastal ecosystem is expected to be exacerbated by anthropogenic CO2 uptake and upwelling.