ozono tropicalTropospheric ozone is an important greenhouse gas. Ozone has exerted an increase in the global radiative forcing of climate almost equal to that of methane over the period between 1750 and 2011. The largest contribution to the climatic influence of ozone is due to its increase in the tropical troposphere. A recent international study, with participation of scientists from the Dept. of Atmospheric Chemistry and Climate of this Institute, shows that ozone concentration in the mid-troposphere (8-10 km) over the western Pacific is three times larger than in the tropics. From the analysis of satellite data, aircraft observations and climate modeling reported here it was concluded that fires in tropical Africa and Southeast Asia are the dominant source of high ozone over the western Pacific. High ozone and low water structures in the tropical western Pacific are commonly attributed to transport from the stratosphere or mid-latitudes. However, these observations suggest a larger role for biomass burning in the radiative forcing of climate in the remote tropical western Pacific than is commonly appreciated.

D. C. Anderson, J. M. Nicely, R. J. Salawitch, T. P. Canty, R. R. Dickerson, T. F. Hanisco, G. M. Wolfe, E. C. Apel, E. Atlas, T. Bannan, S. Bauguitte, N. J. Blake, J. F. Bresch, T. L. Campos, L. J. Carpenter, M. D. Cohen, M. Evans, R. P. Fernandez, B. H. Kahn, D. E. Kinnison, S. R. Hall, N. R. Harris, R. S. Hornbrook, J.-F. Lamarque, M. Le Breton, J. D. Lee, C. Percival, L. Pfister, R. R. Pierce, D. D. Riemer, A. Saiz-Lopez, B. J. Stunder, A. M. Thompson, K. Ullmann, A. Vaughan and A. J. Weinheimer. A pervasive role for biomass burning in tropical high ozone/low water structures. Nature Communications (2015).