ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-7231-2010 First ground-based FTIR observations of methane in the inner tropics over several years Petersen A. K. 1 2 Warneke T. 1 Frankenberg C. 3 Bergamaschi P. 4 Gerbig C. 5 Notholt J. 1 Buchwitz M. 1 Schneising O. 1 Schrems O. 6 Institute of Environmental Physics, University of Bremen, Bremen, Germany Max-Planck Institute for Meteorology, Hamburg, Germany SRON Netherlands Institute for Space Research, Utrecht, The Netherlands Institute for Environment and Sustainability (IES), European Commission Joint Research Centre, Ispra, Italy Max-Planck Institute for Biogeochemistry, Jena, Germany Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany 06 08 2010 10 15 7231 7239 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/10/7231/2010/acp-10-7231-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/7231/2010/acp-10-7231-2010.pdf

Total column concentrations of methane have been retrieved from ground-based solar absorption FTIR spectra in the near-infrared recorded in Paramaribo (Suriname). The methane FTIR observations are compared with TM5 model simulations and satellite observations from SCIAMACHY, and represent the first validation of SCIAMACHY retrievals in the inner tropics using ground-based remote sensing techniques. Apart from local biomass burning features, our methane FTIR observations agree well with TM5 model simulations. The comparison of the direct measured CH<sub>4</sub>/CO<sub>2</sub> ratios by FTIR and satellite reveals that the satellite can hardly detect methane emissions of tropical biomass burning due to the used retrieval method.

 References Andreae, M O. and Merlet, P.: Emission of trace gases and aerosols from biomass burning, Global Biogeochem. Cy., 15, 955–966, 2001. Bergamaschi, P., Krol, M., Dentener, F., Vermeulen, A., Meinhardt, F., Graul, R., Ramonet, M., Peters, W., and Dlugokencky, E. J.: Inverse modelling of national and European CH<sub>4</sub> emissions using the atmospheric zoom model TM5, Atmos. Chem. Phys., 5, 2431–2460, doi:10.5194/acp-5-2431-2005, 2005. Bergamaschi, P., Frankenberg, C., Meirink, J., Krol, M., Dentener, F., Wagner, T., Platt, U., Kaplan, J., Körner, S., Heimann, M., and Goede, A.: Satellite cartography of atmospheric methane from SCIAMACHY on board ENVISAT: II. Evaluation based on inverse model simulations, J. Geophys. Res., 112, D02304, \doi10.1029/2006JD007268, 2007. Bergamaschi, P., Frankenberg, C., Meirink, J F., Krol, M., Villani, M G., Houweling, S., Dentener, F., Dlugokencky, E J., Miller, J B., Gatti, L., Engel, A., and Levin, I.: Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite retrievals, J. Geophys. Res., 114, D22301, \doi10.1029/2009JD01228, 2009. Buchwitz, M., de Beek, R., Noël, S., Burrows, J. P., Bovensmann, H., Schneising, O., Khlystova, I., Bruns, M., Bremer, H., Bergamaschi, P., Körner, S., and Heimann, M.: Atmospheric carbon gases retrieved from SCIAMACHY by WFM-DOAS: version 0.5 CO and CH<sub>4</sub> and impact of calibration improvements on CO<sub>2</sub> retrieval, Atmos. Chem. Phys., 6, 2727–2751, doi:10.5194/acp-6-2727-2006, 2006. Dlugokencky, E J., Steele, L P., Lang, P M., and Masarie, K A.: The growth rate and distribution of atmospheric methane, J. Geophys. Res., 99, 17021–17043, 1994. Dlugokencky, E J., Houweling, S., Bruhwiler, L., Masarie, K A., Lang, P M., Miller, J B., and Tans, P P.: Atmospheric methane levels off: Temporary pause or a new steady state?, Geophys. Res. Lett., 30(19), doi:10.1029/2003GL018126, 2003. Dlugokencky, E. J., Bruhwiler, L., White, J. W. C., et al.: Observational constraints on recent increases in the atmospheric CH<sub>4</sub> burden, Geophys. Res. Lett., 36, L18803, \doi10.1029/2009GL039780, 2009a. Dlugokencky, E J., Lang, P M., and Masarie, K A.: Atmospheric Methane Dry Air Mole Fractions from the NOAA ESRL Carbon Cycle Cooperative Global Air Sampling Network, 1983–2008, Version: 2009-06-18, Path: ftp://ftp.cmdl.noaa.gov/ccg/ch4/flask/event/, 2009b. Dueck, T A., de~Visser, R., Poorter, H., Persijn, S., Gorissen, A., de~Visser, W., Schapendonk, A., Verhagen, J., Snel, J., Harren, F. J M., Ngai, A. K Y., Verstappen, F., Bouwmeester, H., Voesenek, L. A. C J., and van~der Werf, A.: No evidence for substantial aerobic methane emission by terrestrial plants: A 13C-labelling approach, New Phytol., 175, 29–35, doi:10.1111/j.1469-8137.2007.02103.x, 2007. Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D., Haywood, J., Lean, J., Lowe, D., Myhre, G., Nganga, J., R Prinn, G Raga, M S., and Dorland, R V.: Changes in Atmospheric Constituents and in Radiative Forcing, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), 2007. Fortuin, J., Becker, C., Fujiwara, M., Immler, F., Kelder, H M., Scheele, M P., Schrems, O., , and Verver, G. H L.: Origin and transport of tropical cirrus clouds observed over Paramaribo, Suriname (5.8°N, 55.2°W), J. Geophys. Res., 112, D09107, \doi10.1029/2005JD006420, 2007. Frankenberg, C., Meirink, J F., van Weele, M., Platt, U., and Wagner, T.: Assessing Methane Emissions from Global Space-Borne Observations, Science, 308, 1010–1014, \doi10.1126/science.1106644, prefixhttp://www.sciencemag.org/cgi/content/abstract/308/5724/1010, 2005. Frankenberg, C., Meirink, J F., Bergamaschi, P., Goede, A. P H., Heimann, M., Körner, S., Platt, U., van Weele, M., and Wagner, T.: Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: Analysis of the years 2003 and 2004, J. Geophys. Res., 111, D07303, \doi10.1029/2005JD006235, 2006. Frankenberg, C., Bergamaschi, P., Butz, A., Houweling, S., Meirink, J.-F., Notholt, J., Petersen, A K., Schrijver, H., Warneke, T., and Aben, I.: Tropical methane emissions: A revised view from SCIAMACHY onboard ENVISAT, Geophys. Res. Lett., 35, L15811, \doi10.1029/2008GL034300, 2008a. Frankenberg, C., Warneke, T., Butz, A., Aben, I., Hase, F., Spietz, P., and Brown, L. R.: Pressure broadening in the 2$_\rm v3$ band of methane and its implication on atmospheric retrievals, Atmos. Chem. Phys., 8, 5061–5075, doi:10.5194/acp-8-5061-2008, 2008b. Houweling, S., Röckmann, T., Aben, I., Keppler, F., Krol, M., Meirink, J F., Dlugokencky, E J., and Frankenberg, C.: Atmospheric constraints on global emissions of methane from plants, Geophys. Res. Lett., 33, L15821, \doi10.1029/2006GL026162, 2006. Keppler, F., Hamilton, J. T G., Braß, M., and Röckmann, T.: Methane emissions from terrestrial plants under aerobic conditions, Nature, 439, 187–191, \doi10.1038/nature04420, prefixhttp://dx.doi.org/10.1038/nature04420, 2006. Kirschbaum, M. U. F. and Walcroft, A.: No detectable aerobic methane efflux from plant material, nor from adsorption/desorption processes, Biogeosciences, 5, 1551–1558, doi:10.5194/bg-5-1551-2008, 2008. Meirink, J., Bergamaschi, P., Frankenberg, C., d'Amelio, M., Dlugokencky, E., Gatti, L., Houweling, S., Miller, J., Röckmann, T., Villani, M., and Krol, M.: Four-dimensional variational data assimilation for inverse modeling of atmospheric methane emissions: Analysis of SCIAMACHY observations, J. Geophys. Res., 113, D17301, \doi10.1029/2007JD009740, 2008a. Meirink, J. F., Bergamaschi, P., and Krol, M. C.: Four-dimensional variational data assimilation for inverse modelling of atmospheric methane emissions: method and comparison with synthesis inversion, Atmos. Chem. Phys., 8, 6341–6353, doi:10.5194/acp-8-6341-2008, 2008b. Miller, J., Gatti, L., d'Amelio, M., Crotwell, A., Dlugokencky, E., Bakwin, P., Artaxo, P., and Tans, P.: Airborne measurements indicate large methane emissions from the eastern Amazon basin, Geophys. Res. Lett., 34, L10809, \doi10.1029/2006GL029213, 2007. Nisbet, R., Fisher, R., Nimmo, R., Bendall, D., P.M, C., Gallego-Sala, A., Hornibrook, E., López-Juez, E., Lowry, D., Nisbet, P., Shuckburgh, E., Sriskantharajah, S., Howe, C J., and Nisbet, E G.: Emission of methane from plants, Proc. R. Soc., 276, 1347–1354, \doi10.1098/rspb.2008.1731, 2009. Petersen, A K., Warneke, T., Lawrence, M G., Notholt, J., and Schrems, O.: First ground-based FTIR observations of the seasonal variation of carbon monoxide in the tropics, Geophys. Res. Lett., 35, L03813, \doi10.1029/2007GL031393, 2008. Rigby, M., Prinn, R G., Fraser, P J., Simmonds, P G., Langenfelds, R L., Huang, J., Cunnold, D M., Steele, L P., Krummel, P B., Weiss, R F., O'Doherty, S., Salameh, P K., Wang, H J., Harth, C M., Mühle, J., and Porter, L W.: Renewed growth of atmospheric methane, J. Geophys. Res., 35, L22805, \doi10.1029/2008GL036037, 2008. Rinsland, C. P., Goldman, A., Murcray, F. J., Murcray, F. H., Blatherwick R. D., and Murcray, D. G.: Infrared Measurements of Atmospheric Gases Above Mauna Loa, Hawaii, in February 1987, J. Geophys. Res., 93(D10), 12607–12626, doi:10.1029/JD093iD10p12607, 1988. Rinsland, C P., Jones, N B., Connor, B J., Logan, J A., Pougatchev, N S., Goldman, A., Murcray, F J., Stephen, T M., Pine, A S., Zander, R., Mahieu, E., and Demoulin, P.: Northern and Southern hemisphere ground-based infrared spectroscopic measurements of tropospheric carbon monoxide and ethane, J. Geophys. Res., 103, 28197–28217, 1998. Rödenbeck, C.: Estimating CO<sub>2</sub> sources and sinks from atmospheric mixing ratio measurements using a global inversion of atmospheric transport, Tech. Rep 6, Max Planck Institute for Biogeochemistry, 2005. Schneising, O., Buchwitz, M., Burrows, J. P., Bovensmann, H., Bergamaschi, P., and Peters, W.: Three years of greenhouse gas column-averaged dry air mole fractions retrieved from satellite – Part 2: Methane, Atmos. Chem. Phys., 9, 443–465, doi:10.5194/acp-9-443-2009, 2009. Senten, C., De Mazière, M., Dils, B., Hermans, C., Kruglanski, M., Neefs, E., Scolas, F., Vandaele, A. C., Vanhaelewyn, G., Vigouroux, C., Carleer, M., Coheur, P. F., Fally, S., Barret, B., Baray, J. L., Delmas, R., Leveau, J., Metzger, J. M., Mahieu, E., Boone, C., Walker, K. A., Bernath, P. F., and Strong, K.: Technical Note: New ground-based FTIR measurements at Ile de La Réunion: observations, error analysis, and comparisons with independent data, Atmos. Chem. Phys., 8, 3483–3508, doi:10.5194/acp-8-3483-2008, 2008. Wang, Z.-P., Han, X.-G., Wang, G G., Song, Y., and Gulledge, J.: Aerobic methane emission from plants in the inner Mongolia steppe, Environ. Sci. Technol., 42(1), 62–68, 2008. Warneke, T., Meirink, J F., Bergamaschi, P., Grooß, J U., Notholt, J., Toon, G C., Velazco, V., Goede, A. P H., and Schrems, O.: Seasonal and latitudinal variation of atmospheric methane: A ground-based and ship-borne solar IR spectroscopic study, Geophys. Res. Lett., 33, L14812, \doi10.1029/2006GL025874, 2006. Washenfelder, R A., Wennberg, P O., and Toon, G C.: Tropospheric methane retrieved from ground-based near-IR solar absorption spectra, Geophys. Res. Lett., 30, 2226, \doi10.1029/2003GL017969, 2003.