We seek to better predict the rate of Southern Ocean carbon uptake over the next several decades to centuries. This will require a thorough understanding of the variable and changing carbonate chemistry of the Southern Ocean, including better constraints on the present-day mean state and seasonal cycle, quantification of past variability, and characterization of key processes driving change in the future.
The primary numerical tool for this project is the Community Earth System Model (CESM), a state-of-the-art Earth system model with fully interactive marine ecosystem and global carbon modules. Output from hindcast and 21st century CESM simulations, hydrographic data, and satellite data products will be used to understand model biases, interpret variability, and quantify carbon-climate feedback strength. The specific objectives are to:
- Analyze biases in, and guide improvement of, the Southern Ocean alkalinity cycle in the CESM;
- Quantify multi-decadal changes in modeled Southern Ocean carbonate chemistry over the last 60 years, and validate these trends with satellite and hydrographic data sets;
- Identify drivers of interannual to multi-decadal variability in Southern Ocean carbonate chemistry; and
- Quantify carbon feedbacks in the Southern Ocean due to changes in acidification, stratification, and wind-driven circulation.