Submitted on October 22, 2004
Accepted on March 9, 2005
Assessing Methane Emissions from Global Space-Borne Observations
Christian Frankenberg 1,
Jan Fokke Meirink 2,
Michiel van Weele 2,
Ulrich Platt 1,
Thomas Wagner 1
1 Institute of environmental physics, University of Heidelberg, INF 229, 69120 Heidelberg, Germany.
2 Royal Netherlands Meteorological Institute, Section of Atmospheric Composition, P. O. Box 201, 3730 AE De Bilt, The Netherlands.
In the past two centuries, atmospheric methane has more than doubled and now constitutes 20% of the anthropogenic climate forcing by greenhouse gases. Yet its sources are not well quantified, introducing uncertainties in its global budget. We retrieved the global methane distribution using space-borne near-infrared absorption spectroscopy. In addition to the expected latitudinal gradient, we detect large-scale patterns of anthropogenic and natural methane emissions. Furthermore, we observe unexpectedly high methane concentrations over tropical rainforests revealing that emission inventories considerably underestimate methane sources in these regions during the time period of investigation (August-November 2003).
