Estimation of Carbon Dioxide Fluxes Between Land, Ocean and Atmosphere During 2006–2011 with a 4D Variational Assimilation Scheme and Special Reference to Asia

The rates of exchange of carbon dioxide between atmosphere, land and ocean is a key component of the global carbon budget. It is extremely important to quantify these both on a spatial and temporal basis as it can identify sources and sinks of anthropogenic carbon which are important in setting goals for country-wise emissions and uptake. This chapter presents results from a 4D variational assimilation scheme of ingesting carbon dioxide data between 2006 and 2011 into the adjoint of the LMDZ transport model to obtain fluxes between land, ocean and atmosphere. Carbon dioxide data from three stations from India (Hanle, Pondicherry and Port Blair) along with one hundred global stations have been assimilated into the model, and this is expected to increase the confidence in the results for the tropical and temperate Asian regions. The grid point-wise results are aggregated into larger regions representing India, China, USA, Western Europe and the Rest of the World to reflect the quantification of sources and sinks in these regions. In addition, aggregation in terms of Transcom regions is also presented.