An Investigation of CO2 Signals Caused by Weather Disturbances in Mamala Bay

Abstract

With continued increase of atmospheric carbon dioxide concentrations due to human activity, it is important to maintain an understanding of the carbon dioxide (CO2) concentrations and cycles in coastal waters. Coastal CO2 fluctuations are highly variable in comparison to open ocean systems, they also differ in roles as sources and sinks for atmospheric CO2. This study was an investigation on the effects of weather events, such as Kona-storms, on CO2 concentrations and fluctuations in the coastal waters of Oahu's South-Shore. CO2 data has been collected in the coastal waters of O’ahu with the use of Moored Autonomous Partial-pressure CO2 (MAPCO2) sensors since 2008. These data were combined with hydrology data from the United States Geological Survey in order to detail weather disturbance effects on pCO2 cycles in the near shore system of Mamala Bay, Hawaii. Biological processes dominate the short-term CO2 fluctuations in the near-shore system, but these cycles can be disrupted by weather events and the effects that those weather events have on the biological activity in the system. We found that the disturbances were identifiable in the data record by CO2 signals. High CO2 signals and low signals were identified, the highest and lowest both correlated with weather disturbances prior to the signals.