Models of ocean carbon cycle processes include air-sea gas exchange, ecosystem dynamics, and transport of nutrients and other biogeochemical constituents in the oceans. Terrestrial carbon cycle models include photosynthesis and respiration; seasonal phenology; allocation, nutrient cycling, and decomposition; disturbance and succession; land use and land cover change. Atmospheric carbon cycle processes included in models are advection, convection, turbulence, and reactions of carbon gases. A rich suite of observations from both in-situ and spaceborne platforms is available for comparison to the predictions of such models. Estimation theory and methods have been developed over decades in meteorological and other geophysical data assimilation research and are now being applied to state and parameter estimation in carbon cycle science.
As examples of recent results, we present estimates of air-sea exchange of CO2 derived by assimilation of satellite sea-surface temperature, topography, and winds into a coupled physical-biogeochemical ocean model. The system describes spatial, seasonal, and interannual variations in CO2 fluxes over the multidecadal record, highlighting effects of El Nino and other climate variations. We also present gridded estimates of terrestrial sources and sinks derived from remotely-sensed vegetation imagery and in-situ measurements of atmospheric CO2 using both global and mesoscale transport models.
Supplementary URL: http://biocycle.atmos.colostate.edu