ARAGONITE SATURATION STATE IN THE SOUTHWESTERN EAST/JAPAN SEA DURING SUMMER
East/Japan Sea is a marginal sea that has a diverse and economically important ecosystem threatened by anthropogenic impacts associated with climate change, urbanization, and ocean acidification. Dissolved inorganic carbon (DIC) and total alkalinity (TA) were precisely measured within the water depth of 300 m in southwestern East/Japan Sea during summer to assess spatial variations of aragonite saturation state. TA ranged from 2154 to 2286 µmol/kg over a salinity range of 31.2 to 34.4. Vertical distribution of TA was generally parallel with that of salinity. DIC ranged from 1760 to 2207 µmol/kg over a density range of 21 to 27.3. The water column along the northernmost and southernmost transect lines (transect D and A) was supersaturated with respect to aragonite from the coast to the outer shelf. However, aragonite undersaturated waters were observed at the water depths of 200 m of the transect A and B and at 250 m of the transect C. Such shallow depth aragonite undersaturation has been rarely found in the world oceans, except for the Arctic Oceans and coastal upwelling areas. In the study area, we did not find any evidence of the coastal upwelling. It is very unique that aragonite is undersaturated at the water depths of 200 m in the East/Japan Sea located in the middle latitude. The shallow occurrence of aragonite undersaturation is ascribed to the cold water ( <2 °C) and the intense remineralization of organic matter at the depth of 200-300 m.
Choi, Y., University of Science and Technology, South Korea, firstname.lastname@example.org
Kim, D., Korea institute of Ocean Science and Technology, South Korea, email@example.com
Rhee, T., Korea Polar Research Institute , South Korea, firstname.lastname@example.org
Time: 11:00 - 12:00
Location: Poster/Exhibit Hall
Presentation is given by student: Yes