The proposed synthesis is in response to NASA ROSES 2013 A.5 Carbon Cycle Science, Theme 6: Carbon Cycle Science Synthesis Research. We propose a focused synthesis effort to address the current gaps, quantification and understanding of the Gulf of Mexico air-sea CO2 fluxes. With existing data, we will explore the use of models and their validity and predictive capacity for carbon cycling Gulf-wide. This research will also provide progress in improving carbon cycle and ecosystem models and in improving predictive capability. Our collaboration has strong linkages with USGS, NOAA, international and academic partners to further understanding of carbon dynamics in the Gulf of Mexico. As such this research will further the aims of the U.S. Climate Change Science Program (CCSP) to investigate nature and human-induced changes in the Earth’s global environment system, predict global change, and provide sound scientific basis for national and international decision-making.
This synthesis effort is scientifically important because it will address the long-standing question of sinks and sources of carbon dioxide in the entire Gulf of Mexico, where they are, and how they change seasonally and, where data exist, monthly. These data will be produced at a much finer scale than the Takahashi et al. (2009) (T09) climatology and include the coastal regions that are not part of the T09 effort. It will lay the foundation for further exploration how the Gulf will respond with increasing atmospheric CO2 levels and areas that are most vulnerable to increases in CO2. The synthesis will shed light on the effect of variable river runoff and how weather patterns and storms impact interannual variability. The basic data compiled and conclusions drawn and the understanding learned here will also provide an important reference point for assessing future changes in carbon flux and budget in this important regions and for predicting potential changes in CO2 flux and ocean acidification status under predicted future climate and anthropogenic forcings.
In recent years, the ocean and climate change community has increasingly recognized the importance of ocean acidification, OA (due to ocean uptake of anthropogenic CO2 from the atmosphere) and its impacts on ocean biology, ecosystems and biogeochemistry (Doney 2010). In some coastal oceans, such as in the northern GOM, the OA issue is further aggravated by the excessive respiration associated with the eutrophication and hypoxia events (Cai et al. 2011; Sunda and Cai 2012). In addition to the CO2 flux and budget, this project will also provide the first Gulfwide current OA status report, which will be very useful for future reference as OA is predicted to become more serious issue in the future.
This proposed effort builds on prior NASA-, NSF- and NOAA-funded work by the PIs examining land processes influencing delivery of carbon and nutrients to coastal waters and the associated spatial variability of air-sea CO2 flux and coastal-ocean exchanges in the GOM. It is notable that the Southeastern United States has been identified as a strong candidate for a Mid Continent Intensive “Follow-On” experiment to better constrain terrestrial fluxes and this work would substantially complement such an effort. Three-dimensional realistic numerical modeling is a critical tool for achieving maximal scientific benefit from the advanced data streams to be produced by the extensive field surveys. Models will aid in synthesizing the observations into space-time continuous fields from which complex physical, biological, and chemical processes can be deduced. Other impacts of this proposed research include enhancement of research and education through postdoctoral training and development of graduate curricula in earth sciences.