Significant contribution of dissolved organic matter to seawater alkalinity

• Published in: Geophysical Research Letters
• Main Authors: Kim, HC, Lee, K
• Other Authors: 환경공학부, 10056383
• Format: Article in Journal/Newspaper
• Language: English
• Published: AMER GEOPHYSICAL UNION 2009
• Subjects: CARBONIC-ACID; DISSOCIATION-CONSTANTS; TITRATION ALKALINITY; PHYTOPLANKTON; DIOXIDE; GROWTH; PH; Carbonic acid
• Online Access: https://oasis.postech.ac.kr/handle/2014.oak/27799; https://doi.org/10.1029/2009GL040271

The present study shows a previously undocumented role of dissolved organic matter in the marine carbonate system. During photosynthesis, phytoplankton release dissolved organic compounds containing basic functional groups that readily react with protons during seawater titration, and thereby contribute to alkalinity (a measure of buffering capacity). The magnitude of the contribution of dissolved organic compounds to seawater alkalinity is species dependent, suggesting that individual phytoplankton species exude dissolved organic compounds with unique proton accepting capacities. Our study shows that dissolved organic matter produced by marine phytoplankton during photosynthesis is a newly identified buffering component in the ocean, and indicates that the contribution of dissolved organic matter to seawater alkalinity can be significant in the biologically productive upper ocean, where to date it has been unrecognized or considered insignificant. Citation: Kim, H.-C., and K. Lee (2009), Significant contribution of dissolved organic matter to seawater alkalinity, Geophys. Res. Lett., 36, L20603, doi:10.1029/2009GL040271. X 1 1 45 47 scie scopus