Robbins, Lisa: University of Southern Florida (Project Lead)
Cai, Wei-Jun: University of Delaware (Co-Investigator)
Wanninkhof, Rik: NOAA/AOML (Institution Lead)
Project Funding:
2014 - 2017
NRA: 2013 NASA: Carbon Cycle Science
Funded by NASA
Abstract:
Uncertainties in coastal carbon fluxes are such that the net uptake of carbon in the coastal margins remains a poorly constrained term in global budgets. The SOCCR Report (Takahashi et al., 2009) indicated that the Gulf of Mexico (GOM) was the single largest area that was unknown with respect to the direction of CO2 flux (i.e., sink or source) in the entire US coastal margin. In 2009 and 2013 regional workshops promoted carbon cycle research in the Gulf of Mexico but a comprehensive region-wide air-sea CO2 flux product has not yet been developed, nor has a sub-regional carbon budget has been established. While good progress has recently been made in collating existing GOM in situ pCO2 data, large data sets still need to be incorporated into the database and yearly, monthly, and seasonal data need to be effectively parsed out. Further, large data gaps in specific regions need to be addressed through effective interpolation techniques utilizing remotely sensed SST, SSS (Aquarius), Color and numerical model output.
During the March 2013 Gulf of Mexico Carbon synthesis workshop, synergies between working groups were identified and the air-sea flux group and modeling group now form the basis for our research team. The team recognizes that significant forward progress and wrap-up of major aspects of the carbon budget could be achieved by a focused effort. We propose a data synthesis and modeling plan with the following goals:
- Produce a whole GOM monthly air-sea CO2 flux climatology with detail in regional and seasonal variations and associated uncertainties.
- Produce a whole GOM inorganic carbon budget based on observational and modeling approach with understanding on carbon cycling processes.
- Produce detailed regional studies in Northern GOM and West Florida shelf, focusing on seasonal and spatial changes, weather events, and ocean acidification which influence surface water CO2 distribution and air-sea CO2 fluxes.
- Compare model -derived and observation- derived estimates to understand processes that control sea-air fluxes in the different provinces.
To achieve our goals, data mining within the carbon community will be performed and datasets will be QA/QCd, formatted, and incorporated into the database. pCO2 air-sea fluxes will be calculated using computed second moment of monthly wind speeds within 5 GOM regions. Open ocean data will be gridded into 1° x 1° bins and coastal ocean data into 0.5° x 0.5° bins. A monthly climatological study centered on the most extensive yearly dataset will be produced and used for model verification.
An existing South Atlantic Bight and Gulf of Mexico (SABGOM) three-dimensional physical-biogeochemical model [Hyun and He, 2010; Xue et al., 2013] will be applied to simulate and examine temporal and spatial variability of biogeochemical cycling, and qualify air-sea CO2 flux and carbon budget in the entire GOM. The model will allow direct comparison of model solutions against in-situ observations, and fill temporal and spatial gaps. Monte Carlo methods will be used to estimate uncertainties from modeling algorithms, parameters, input data, and model coupling, and will include the effects of different approaches and scaling of wind speed products and gas transfer velocities.
We are responding to Theme 6 Carbon Cycle Science Synthesis Research to create a GOM air-sea synthesis from existing data, establishing a baseline for further exploration. This focused synthesis effort is scientifically important because it will address the current gaps within GOM air-sea CO2 flux data and address the long-standing question of sinks and sources of carbon in the entire GOM, where they are, and how they change seasonally and monthly. These high resolution data will lay the foundation for exploration how the Gulf will respond to increasing atmospheric CO2 levels and the areas most vulnerable.
Publications:
Robbins, L. L., Daly, K. L., Barbero, L., Wanninkhof, R., He, R., Zong, H., Lisle, J. T., Cai, W., Smith, C. G. 2018. Spatial and Temporal Variability of
p
CO
2
, Carbon Fluxes, and Saturation State on the West Florida Shelf. Journal of Geophysical Research: Oceans. 123(9), 6174-6188. DOI: 10.1029/2018JC014195
2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)
- Ocean margins as an increasing sink for the atmospheric carbon dioxide
-- (Wei-Jun Cai, Goulven Laruelle, Xinping Hu, Pierre Regnier)
[abstract]
More details may be found in the following project profile(s):
