Global and Brazilian carbon response to El Niño Modoki 2011-2010

The El Nino Modoki in 2010 led to historic droughts in Brazil. In order to understand its impact on carbon cycle variability, we derive the 2011 - 2010 annual carbon flux change (delta F-up arrow) globally and specifically to Brazil using the NASA Carbon Monitoring System Flux (CMS-Flux) framework. Satellite observations of CO2, CO, and solar-induced fluorescence (SIF) are ingested into a 4D-variational assimilation system driven by carbon cycle models to infer spatially resolved carbon fluxes including net ecosystem production, biomass burning, and gross primary productivity (GPP). The global 2011 - 2010 net carbon flux change was estimated to be delta F-up arrow = -1.60 PgC, while the Brazilian carbon flux change was -0.24 +/- 0.11 PgC. This estimate is broadly within the uncertainty of previous aircraft-based estimates restricted to the Amazon basin. The 2011-2010 biomass burning change in Brazil was -0.24 +/- 0.036 PgC, which implies a near-zero 2011-2010 change of the net ecosystem production (NEP): The near-zero NEP change is the result of quantitatively comparable increases GPP (0.31 +/- 0.20 PgC) and respiration in 2011. Comparisons between Brazilian and global component carbon flux changes reveal complex interactions between the processes controlling annual land-atmosphere CO2 exchanges. These results show the potential of multiple satellite observations to help quantify and spatially resolve the response of productivity and respiration fluxes to climate variability.