ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-3505-2010 OMI and MODIS observations of the anomalous 2008–2009 Southern Hemisphere biomass burning seasons Torres O. 1 Chen Z. 1 Jethva H. 1 Ahn C. 2 Freitas S. R. 3 Bhartia P. K. 4 Dept. of Atmospheric and Planetary Sciences, Hampton University, Hampton, Virginia, USA Science Systems and Applications Inc., Lanham, Maryland, USA Center for Weather Forecasting and Climate Studies, INPE, Cachoeira Paulista, Brazil NASA Goddard Space Flight Center, Greenbelt, Maryland, USA 16 04 2010 10 8 3505 3513 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/3505/2010/acp-10-3505-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/3505/2010/acp-10-3505-2010.pdf

Significant inter-annual variability of biomass burning was observed in South America over the 2007–2009 period. The 2007 number of fires detected from space in South America, as well as the magnitude of the atmospheric aerosol load resulting from fire activity, was the largest over the last ten years. The huge 2007 increase in fire activity was followed by large reductions in the 2008 and 2009 burning seasons. Large drops of the atmospheric load of carbonaceous aerosols over the subcontinent, relative to previous years, was registered in 2008 and 2009 by the OMI sensor onboard the Aura platform, and the MODIS sensors on the Terra and Aqua satellites. The 2009 fire season in South America was the least active of the last ten years. Satellite observations of fire statistics, precipitation, and aerosol optical depth data were used to analyze the fire season over South America and Central Africa during the last ten years to understand the factors that led to the 2007 and 2009 extremes. An analysis of precipitation anomaly data shows that the largest 6-month (May–October) precipitation deficit of the last ten years in South America occurred during 2007. The same analysis indicates that in 2009, this region experienced the largest excess precipitation of the decade. Since precipitation is the most important meteorological factor controlling biomass burning activity, it can be concluded that the 2007 maximum and 2009 minimum in fire activity and aerosol load were driven by the observed levels of precipitation. Analysis of the precipitation record, however, does not explain the extremely low 2008 biomass burning activity. Although the 2008 precipitation deficit was similar in magnitude to the one that in 2005 contributed to the second most intense biomass burning season in the last ten years, the 2008 fire season was surprisingly weak. The combined analysis of satellite data on atmospheric aerosol load, fire counts and precipitation strongly suggests that the observed 2008 decline in aerosol load and fire activity in South America was heavily influenced by conditions other than meteorological factors.

 References Duncan, B. N., R. V. Martin, A. C. Staudt, R. Yevich, and J. A. Logan, Interannual and seasonal variability of biomass burning emissions constrained by satellite observations, J. Geophys. Res., 108(D2), 4100, doi:10.1029/2002JD002378, 2003 Eck, T. F., Holben, B. N., Ward, D. E., Dubovik, O., Reid, J. S., Smirnov, A., Mukelabai, M. M., Hsu, N. C., O'Neill, N. T., and Slutsker, I.: Characterization of the optical properties of biomass burning aerosols in Zambia during the 1997 ZIBBEE field campaign, J. Geophys. Res., 106(D4), 3425–3448, 2001. Freitas, S. R., Longo, K. M., Siva-Dias, M. A. F., Silva-Dias, P. L., Chatfield, R., Prins, E., Artaxo, P., Grell, G. A., and Recuero, F. S.: Monitoring the transport of biomass burning emissions in South America, Environ. Fluid Mech., 5, 135–167, doi:10.1007/s10652-005-0243-7, 2005. Freitas, S. R., Longo, K. M., and Andreae, M.: Impact of including the plume rise of vegetation fires in numerical simulations of associated atmospheric pollutants, Geophys. Res. Lett., 33, L17808, doi:10.1029/2006GL026608, 2006. Giglio, L., Csiszar, I., and Justice, C. O.: Global distribution and seasonality of active fires as observed with the Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, J. Geophys. Res., 111, G02016, doi:10.1029/2005JG000142, 2006. Gleason, J. F., Hsu, N. C., and Torres, O.: Biomass burning smoke measured using ackscattered ultraviolet radiation: SCAR-B and Brazilian smoke interannual variability, J. Geophys. Res., 103(D24), 31969–31978, 1998 Gloudemans, A. M. S., de Laat, A. T. J., Schrijver, H., Aben, I., Meirink, J. F., and van der Werf, G. R., SCIAMACHY CO over land and oceans: 2003–2007 interannual variability, Atmos. Chem. Phys., 9, 3799–3813, 2009 Hobbs, P. V., Reid, J. S., Kotchenruther, R. A., Ferek, R. J., and Weiss, R.: Direct radiative forcing by smoke from biomass burning, Science, 272, 1776– 1778, 1997 Hsu, N., Herman, J., Torres, O., Holben, B., Tanre, D., Eck, T., Smirnov, A., Chatenet, B., and Lavenu, F.: Comparisons of the TOMS aerosol index with Sun-photometer aerosol optical thickness: Results and applications, J. Geophys. Res., 104(D6), 6269–6279, 1999. Jacob, D. J., Heikes, B. G., Fan, S. M., et al.: Origin of ozone and NOx in the tropical troposphere: A photochemical analysis of aircraft observations over the South Atlantic basin, J. Geophys. Res., 101(D19), 24235–24250, 1996. Kalnay, E., Kanamitsua, M., Kistlera, R., et al.: The NCEP/NCAR 40-year Reanalysis Project, B. Am. Meteorol. Soc., 77, 437–471, 1996. Koren, I., Remer, L. A., and Longo, K.: Reversal of trend of biomass burning in the Amazon, Geophys. Res. Lett., 34, L20404, doi:10.1029/2007GL031530, 2007. Koren, I., Remer, L. A., Longo, K., Brown, F., and Lindsey, R.: Reply to comment by W. Schroeder et al. on "Reversal of trend of biomass burning in the Amazon," Geophys. Res. Lett., 36, L03807, doi:10.1029/2008GL036063, 2009. Kummerow, C., Simpson, J., Thiele, O., et al.: The status of Tropical Rainfall Measuring Mission (TRMM) after two years in orbit, J. Appl. Meteorol., 12, 1965–1982, 2000. Labonne, M., Breon, F.-M., and Chevallier, F.: Injection height of biomass burning aerosols as seen from a spaceborne lidar, Geophys. Res. Lett., 34, L11806, doi:10.1029/2007GL029311, 2007. Laurance, W.: Switch to Corn Promotes Amazon Deforestation, Science, 318(5857), 1721, doi:10.1126/science.318.5857.1721b, 2007. Levy, R. C., Remer, L. A., Mattoo, S., Vermote, E. F., and Kaufman, Y. J.: Second-generation operational algorithm: Retrieval of aerosol properties over land from inversion of Moderate Resolution Imaging Spectroradiometer spectral reflectance, J. Geophys. Res., 112, D13211, doi:10.1029/2006JD007811, 2007. Malhi, Y., Roberts, J., Betts, R., Killeen, T., Li, W., and Nobre, C, Climate Change, Deforestation, and the Fate of the Amazon. Science, 319 (5860), 169–172. doi:10.1126/science.1146961, 2008. Pielke Sr., R. A., Chase, T. N., Kittel, T. G. F., Knaff, J. A., and Eastman, J.: Analysis of 200 mbar zonal wind for the period 1958–1997, J. Geophys. Res., 106(D21), 27287–27290, 2001. Schroeder, W., Giglio, L., and Arave'quia, J. A.: Comment on "Reversal of trend of biomass burning in the Amazon" by Ilan Koren, Lorraine A. Remer, and Karla Longo, Geophys. Res. Lett., 36, L03806, doi:10.1029/2008GL035659, 2009 Torres, O., Tanskanen, A., Veihelmann, B., Ahn, C., Braak, R., Bhartia, P. K., Veefkind, P., and Levelt, P.: Aerosols and surface UV products from Ozone Monitoring Instrument observations: An overview, J. Geophys. Res., 112, D24S47, doi:10.1029/2007JD008809, 2007. Uhl, C., Kauffman, J. B., and Cummings, D. L.: Fire in the Venezuelan Amazon 2: Environmental conditions necessary for forest fires in the evergreen rainforest of Venezuela, Oikos, 53(2), 176–184, 1988. van der Werf, G. R., Randerson, J. T., Giglio, L., Gobron, N., and Dolman, A. J.: Climate controls on the variability of fires in the tropics and subtropics, Global Biogeochem. Cy., 22, GB3028, doi:10.1029/2007GB003122, 2007. Ziemke, J. R., Chandra, S., Duncan, B. N., Schoeberl, M. R., Damon, M. R., Torres, O., and Bhartia, P. K.: Recent biomass burning events in the tropics and elevated concentrations of tropospheric ozone, Geophys. Res. Lett., 36, L15819, doi:10.1029/2009GL039303, 2009.