The seasonality of ozone profile at Reunion island: the role of biomass burning and of transport

Vertical ozone profiles obtained from ozone soundings at Reunion island (21S-55E) present a seasonal variability. High values of ozone concentration are observed in the troposphere above the inversion level that caps the marine boundary layer during September to December. Satellite observations using NOAA (National Oceanic and Atmospheric Administration) data indicate that this period corresponds to active biomass burning and the beginning of deep convection clouds in Southeastern Africa and Madagascar. Furthermore, analysis of backtrajectories obtained from Reunion island clearly evidence the role of long distance transports from biomass burning sources. Strong variation of ozone profiles are associated, through this transport, with fires, smoke plumes and deep convective structures present in the studied regions.