Ocean carbon dynamics associated with natural and anthropogenic climate change

• Main Author: 고영호
• Other Authors: 일반대학원 환경공학부
• Format: Thesis
• Language: English
• Published: 포항공과대학교 2016
• Subjects: Pacific; Southern Ocean
• Online Access: http://postech.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000002229318; https://oasis.postech.ac.kr/handle/2014.oak/93837

Doctor The ocean dissolves a large amount of the anthropogenic CO2 that is emitted by combustion of fossil fuel, and may thereby moderate future climate change. However, acidification caused by dissolved CO2 affects the carbonate system and significant effects marine biogeochemical cycles and ecosystems. Several modeling studies have assessed possible change in ocean chemistry under various CO2 concentration and emission scenarios. To be accurate, projections of oceanic carbonate chemistry should be made with understanding of natural variability in the oceanic carbonate system. Limited observations indicate that the carbonate chemistry of the surface ocean is significantly influenced by global and regional climate changes, but the effect has not been well constrained. Because of complex interplay among physical and biogeochemical processes, the ocean carbonate system varies substantially among environments and on various time scales. Understanding of how the ocean carbonate system will react to continued increase in anthropogenic CO2 requires research on the influence of climate change on each process. The goal of this thesis is to improve our understanding of climate variability and how it affects the oceanic carbonate system. I conducted research that disclosed a link between carbonate chemistry and large-scale climatic predictors including the El Niño Southern Oscillation (ENSO) and Southern Annular Mode in two different locations: the Chuuk coral reef in the western Pacific (Chapter 2) and the Southern Ocean (Chapter 3). In coastal waters, human inputs of nutrients can lead to excessive production of algae (eutrophication). During photosynthesis, phytoplankton release organic acids that react with protons during seawater titration, and thereby contribute to total alkalinity. The third study of the thesis work concentrates on evaluating a non-conservative variation of total alkalinity caused by organic acid accumulation (Chapter 4). As the amount of anthropogenic CO2 in the ocean increase, adverse effects ...