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JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, D07303, doi:10.1029/2005JD006235, 2006

Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: Analysis of the years 2003 and 2004

C. Frankenberg

Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany


J. F. Meirink

Section of Atmospheric Composition, Royal Netherlands Meteorological Institute, De Bilt, Netherlands


P. Bergamaschi

European Commission Joint Research Centre, Ispra, Italy


A. P. H. Goede

Section of Atmospheric Composition, Royal Netherlands Meteorological Institute, De Bilt, Netherlands


M. Heimann

Max Planck Institute for Biogeochemistry (MPI-BGC), Jena, Germany


S. Körner

Max Planck Institute for Biogeochemistry (MPI-BGC), Jena, Germany


U. Platt

Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany


M. van Weele

Section of Atmospheric Composition, Royal Netherlands Meteorological Institute, De Bilt, Netherlands


T. Wagner

Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany


Abstract

The UV/Vis/near infrared spectrometer SCIAMACHY on board the European ENVISAT satellite enables total column retrieval of atmospheric methane with high sensitivity to the lower troposphere. The vertical column density of methane is converted to column averaged mixing ratio by using carbon dioxide retrievals as proxy for the probed atmospheric column. For this purpose, we apply concurrent total column measurements of CO2 in combination with modeled column-averaged CO2 mixing ratios. Possible systematic errors are discussed in detail while the precision error is 1.8% on average. This paper focuses on methane retrievals from January 2003 through December 2004. The measurements with global coverage over continents are compared with model results from the chemistry–transport model TM4. In the retrievals, the north-south gradient as well as regions with enhanced methane levels can be clearly identified. The highest abundances are found in the Red Basin of China, followed by northern South America, the Gangetic plains of India and central parts of Africa. Especially the abundances in northern South America and the Red Basin are generally higher than modeled. Further, we present the seasonal variations within the investigated time period. Peak values in Asia due to rice emissions are observed from August through October. We expand earlier investigations that suggest underestimated emissions in the tropics. It is shown that these underestimations show a seasonal behavior that peaks from August through December. The global measurements may be used for inverse modeling and are thus an important step towards better quantification of the methane budget.

Received 18 May 2005; accepted 23 January 2006; published 8 April 2006.

Keywords: methane; atmospheric chemistry; satellite remote sensing.

Index Terms: 1640 Global Change: Remote sensing (1855); 1610 Global Change: Atmosphere (0315, 0325); 1615 Global Change: Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912); 1631 Global Change: Land/atmosphere interactions (1218, 1843, 3322); 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry.

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Citation: Frankenberg, C., J. F. Meirink, P. Bergamaschi, A. P. H. Goede, M. Heimann, S. Körner, U. Platt, M. van Weele, and T. Wagner (2006), Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: Analysis of the years 2003 and 2004, J. Geophys. Res., 111, D07303, doi:10.1029/2005JD006235.