Project: Does the strength of the carbonate pump change with ocean stratification and acidification and how?

Extracted from the NSF award abstract:

This project will improve the ability to predict the response of the carbonate pump to ocean acidification and stratification through enhanced understanding of the controlling factors of the export of CaCO3 from the surface and cycling through the water column and sediments. Key questions to be addressed are (i) Does the strength of the carbonate pump change in response to ocean acidification and stratification? (ii) Is the CaCO3 export more closely associated with the tightly recycling picoplankton and nanoplankton ecosystems than the blooming microplankton? (iii) What is the role of interactions between organic particle fluxes and the saturation state of seawater with respect to CaCO3 minerals in the dissolution of CaCO3 in the water column and sediments? The above three questions will be addressed in a unified model-observation framework where a suite of global models of the carbonate pump will be objectively assessed using a wide range of observations. An already assembled and analyzed global database of ocean biogeochemical tracers and sediment traps will be combined with 3-D numerical model frameworks. The work will be done using a time-efficient solver that allows for systematic model optimization and sensitivity analyses. This work will be incorporated into earth system models developed by the NOAA Geophysical Fluid Dynamics Laboratory for assessment of the interactive role of marine ecosystems and ocean acidification in future climate. This work will further help to improve our ability to predict the future role of the ocean in absorbing anthropogenic carbon and also elucidate the oceanic contribution to the glacial/interglacial changes in atmospheric pCO2.

Note: Eun-Young Kwon is a former Co-PI on this project

Gridded global fields used in the manuscripts below are available here. The file contains a compilation of the PACIFICA, CARINA, and GLODAPv1 datasets gridded onto the World Ocean Atlas coordinates. The gridded variables are: CTD Temperature, CTD Salinity, Bottle Salinity, Oxygen, Nitrate, Nitrite, Silicate, Phosphate, DIC, and Alkalinity. The gridding methods are described in the supplement to: doi:10.5194/bgd-11-11139-2014.

Carter, B. R., J. R. Toggweiler, R. M. Key, and J. L. Sarmiento (2014), Processes determining the marine alkalinity and carbonate saturation distributions, Biogeosciences Discuss., 11, 11139-11178, doi:10.5194/bgd-11-11139-2014.

Carter, B. R., L. D. Talley, and A. G. Dickson (2014), Mixing and remineralization in waters detrained from the surface into Subantarctic Mode Water and Antarctic Intermediate Water in the southeastern Pacific. Journal of Geophysical Research: Oceans.

Galbraith, E., E. Y. Kwon, A. Gnanadesikan, K. B. Rogers, S. Griffies, D. Blanchi, J. Sarmiento, J. Dunne, J. Simeon, R. D. Slater, A. Wittenberg, and I. Held (2011): Climate variability and radiocarbon in the CM2Mc earth system model, J. Climate, 24, 4230-4254, doi:10.1175/2011JCLI3919.1

Majkut, J. D., B. R. Carter, T. L. Frӧlicher, C. O. Dufour, K. B. Rodgers, and J. L. Sarmiento, (2014) An observing system simulation for Southern Ocean carbon dioxide uptake, Philos. T. Roy. Soc. A, 372 (2019)

Kwon, E., J. Sarmiento, J. R. Toggweiler, T. DeVries, The control of atmospheric CO2 by ocean ventilation change: The effect of the oceanic storage of biogenic carbon, Global Biogeochem.Cy., 25,2011, doi: 10.1029/2011GB004059

Kwon, E., M., Hain, D. Sigman, E. Galbraith, J. Sarmiento, and R. Toggweiler (2011): North Atlantic ventilation of southern-sourced deep water in the ice age ocean, Paleoceanography, 27, 2012 doi:10.1029/2011PA002211