CO2 fluxes from the plume of Etna Volcano (2006-2011 period). The CO2 flux was calculated from combination of daily averaged CO2/SO2 ratios (acquired using a Multi-GAS of the INGV-PA monitoring network) and daily averaged SO2 fluxes, by the FLux Automatic MEasurement (FLAME) scanning DOAS (Differential Optical Absorption Spectroscopy) network of Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Etneo.