A global coupled Eulerian-Lagrangian model and 1 × 1 km CO2 surface flux dataset for high-resolution atmospheric CO2 transport simulations (2024)

A. Ganshin, T. Oda, M. Saito, S. Maksyutov, V. Valsala, R. J. Andres, R. E. Fisher, D. Lowry, A. Lukyanov, H. Matsueda, E. G. Nisbet, M. Rigby, Y. Sawa, R. Toumi, K. Tsuboi, A. Varlagin, and R. Zhuravlev

Abstract. We designed a method to simulate atmospheric CO₂ concentrations at several continuous observation sites around the globe using surface fluxes at a very high spatial resolution. The simulations presented in this study were performed using the Global Eulerian-Lagrangian Coupled Atmospheric model (GELCA), comprising a Lagrangian particle dispersion model coupled to a global atmospheric tracer transport model with prescribed global surface CO₂ flux maps at a 1 × 1 km resolution. The surface fluxes used in the simulations were prepared by assembling the individual components of terrestrial, oceanic and fossil fuel CO₂ fluxes. This experimental setup (i.e. a transport model running at a medium resolution, coupled to a high-resolution Lagrangian particle dispersion model together with global surface fluxes at a very high resolution), which was designed to represent high-frequency variations in atmospheric CO₂ concentration, has not been reported at a global scale previously. Two sensitivity experiments were performed: (a) using the global transport model without coupling to the Lagrangian dispersion model, and (b) using the coupled model with a reduced resolution of surface fluxes, in order to evaluate the performance of Eulerian-Lagrangian coupling and the role of high-resolution fluxes in simulating high-frequency variations in atmospheric CO₂ concentrations. A correlation analysis between observed and simulated atmospheric CO₂ concentrations at selected locations revealed that the inclusion of both Eulerian-Lagrangian coupling and high-resolution fluxes improves the high-frequency simulations of the model. The results highlight the potential of a coupled Eulerian-Lagrangian model in simulating high-frequency atmospheric CO₂ concentrations at many locations worldwide. The model performs well in representing observations of atmospheric CO₂ concentrations at high spatial and temporal resolutions, especially for coastal sites and sites located close to sources of large anthropogenic emissions. While this study focused on simulations of CO₂ concentrations, the model could be used for other atmospheric compounds with known estimated emissions.

How to cite. Ganshin, A., Oda, T., Saito, M., Maksyutov, S., Valsala, V., Andres, R. J., Fisher, R. E., Lowry, D., Lukyanov, A., Matsueda, H., Nisbet, E. G., Rigby, M., Sawa, Y., Toumi, R., Tsuboi, K., Varlagin, A., and Zhuravlev, R.: A global coupled Eulerian-Lagrangian model and 1 × 1 km CO₂ surface flux dataset for high-resolution atmospheric CO₂ transport simulations, Geosci. Model Dev., 5, 231–243, https://doi.org/10.5194/gmd-5-231-2012, 2012.