Carbon Emissions from the 2015 Indonesian fires

International audienceSmoke from fires plagued Indonesia during the second half of 2015. Slash and burn practices combined with reduced rain due to El Niño conditions intensified biomass burning and led to extremely poor air quality in large parts of Indonesia, Singapore, and Malaysia. Burning of tropical peat forests leads to large emission of carbon (CO2, CO), and first estimates claim that the Indonesian fires in 2015 emitted more carbon than the entire United Kingdom. However, carbon emissions from peat fires are highly uncertain and depend, among others, on the thickness of the peat layer. Top down estimates using satellite measurements and modeling might help to constrain carbon emissions from the Indonesia fires. We will present first estimates of the carbon emissions using TM5-4DVAR, a data-assimilation system that derives CO emissions using satellite observations from IASI. This system has been previsouly applied to the 2010 Russian fires, to the Amazon, and to emissions from Tropical Asia. Using CO/CO2 emissions factors for peat burning we will translate the derived CO emissions into total carbon emissions and validate these numbers with independent observations from e.g. the GOSAT instrument