Effects of the 2006 El Niño on tropospheric ozone and carbon monoxide: implications for dynamics and biomass burning S. Chandra1,2, J. R. Ziemke1,2, B. N. Duncan1,2, T. L. Diehl1,2, N. J. Livesey3, and L. Froidevaux3 1Goddard Earth Sciences and Technology Center, University of Maryland Baltimore County, Baltimore, MD, USA 2NASA Goddard Space Flight Center, Greenbelt, MD, USA 3NASA Jet Propulsion Laboratory, Pasadena, CA, USA
Abstract. We have studied the effects of the 2006 El Niño on
tropospheric O3 and CO at tropical and sub-tropical latitudes measured
from the OMI and MLS instruments on the Aura satellite. The 2006 El Niño-induced
drought caused forest fires (largely set to clear land) to
burn out of control during October and November in the Indonesian region.
The effects of these fires are clearly seen in the enhancement of CO
concentration measured from the MLS instrument. We have used a global model
of atmospheric chemistry and transport (GMI CTM) to quantify the relative
importance of biomass burning and large scale transport in producing
observed changes in tropospheric O3 and CO. The model results show that
during October and November biomass burning and meteorological changes
contributed almost equally to the observed increase in tropospheric O3
in the Indonesian region. The biomass component was 4–6 DU but it was
limited to the Indonesian region where the fires were most intense. The
dynamical component was 4–8 DU but it covered a much larger area in the
Indian Ocean extending from South East Asia in the north to western
Australia in the south. By December 2006, the effect of biomass burning was
reduced to zero and the observed changes in tropospheric O3 were mostly
due to dynamical effects. The model results show an increase of 2–3% in
the global burden of tropospheric ozone. In comparison, the global burden of
CO increased by 8–12%.
Citation: Chandra, S., Ziemke, J. R., Duncan, B. N., Diehl, T. L., Livesey, N. J., and Froidevaux, L.: Effects of the 2006 El Niño on tropospheric ozone and carbon monoxide: implications for dynamics and biomass burning, Atmos. Chem. Phys., 9, 4239-4249, doi:10.5194/acp-9-4239-2009, 2009.