Atmospheric Measurement Techniques Discussions www.atmos-meas-tech-discuss.net 1867-8610 3 4 2010 10.5194/amtd-3-3199-2010 http://www.atmos-meas-tech-discuss.net/3/3199/2010/ http://www.atmos-meas-tech-discuss.net/3/3199/2010/amtd-3-3199-2010.html http://www.atmos-meas-tech-discuss.net/3/3199/2010/amtd-3-3199-2010.pdf 3199 3276 2010-08-02 MAMAP &ndash; a new spectrometer system for column-averaged methane and carbon dioxide observations from aircraft: instrument description and performance assessment K. Gerilowski gerilows@iup.physik.uni-bremen.de A. Tretner T. Krings M. Buchwitz P. P. Bertagnolio F. Belemezov J. Erzinger J. P. Burrows H. Bovensmann University of Bremen, Institute of Environmental Physics, P.O. Box 330440, 28334 Bremen, Germany Helmholtz Centre Potsdam &ndash; GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany now at: University of Siena, Department of Earth Sciences, Via Laterina 8, 53100 Siena, Italy Carbon dioxide (CO₂) and Methane (CH₄) are the two most important anthropogenic greenhouse gases. CH₄ is furthermore one of the most potent present and future contributors to global warming because of its large global warming potential (GWP). Our knowledge of CH₄ sources and sinks is based primarily on sparse in-situ local point measurements from micro sites and surface networks and more recently on low spatial resolution satellite observations. There is a need for measurements of the dry columns of CO₂ and CH₄ having high spatial resolution and spatial coverage. In order to fill this gap a new passive airborne 2-channel grating spectrometer instrument for remote sensing of small scale and mesoscale column-averaged CH₄ and CO₂ observations has been developed. This Methane Airborne MAPper (MAMAP) instrument measures reflected and scattered solar radiation in the short wave infrared (SWIR) and near-infrared (NIR) parts of the electro-magnetic spectrum at moderate spectral resolution. The SWIR channel yields measurements of atmospheric absorption bands of CH₄ and CO₂ in the spectral range between 1.59 and 1.69 μm at a spectral resolution of 0.82 nm. The NIR channel around 0.76 μm measures the atmospheric O₂-A-band absorption with a resolution of 0.46 nm. MAMAP has been designed for flexible operation aboard a variety of airborne platforms. The instrument design and performance, together with some results from on-ground and in-flight engineering tests are presented. The instrument performance has been analyzed using a retrieval algorithm applied to the SWIR channel nadir measured spectra. The signal-to-noise ratio (SNR) of the SWIR channel is approximately 1000 for integration times (<i>t</i>_int) in the range of 0.6–0.8 s for scenes with surface spectral reflectances of around 0.18. At these integration times the ground scene size is about 23&times;33 m² for an aircraft altitude of 1 km and a ground speed of 200 km/h. For these scenes the CH₄ and CO₂ column retrieval precisions are typically about 1% (1 &sigma;). Elevated levels of CH₄ have been retrieved above a CH₄ emitting landfill. Similarly the plume of CO₂ from coal-fired power plants can be well detected and tracked. The measurements by the MAMAP sensor enable estimates of anthropogenic, biogenic and geological emissions of localized intense CH₄ and CO₂ sources such as anthropogenic fugitive emissions from gas industry and waste, emissions from coal-fired power plants or geologic emissions from seepage and volcanoes. Appropriate analysis of the measurements of MAMAP potentially also yields CH₄ emissions from less intense but extensive sources such as wetlands. Archer,~D. and Buffett,~B.: Time-dependent response of the global ocean clathrate reservoir to climatic and anthropogenic forcing, Geochem. Geophys. Geosyst., 6, 3, \doi10.1029/2004GC000854, 2005. Armendariz,~A.: Emissions from natural gas production in the Barnett Shale Area and opportunities for cost effective improvements, Report, Peer-Review draft, Department of Environmental and Civil Engineering, Southern Methodist University, Dallas, Texas, 2008. Barkley, M. P., Frieß, U., and Monks, P. S.: Measuring atmospheric \chemCO_2 from space using Full Spectral Initiation (FSI) WFM-DOAS, Atmos. Chem. Phys., 6, 3517–3534, doi:10.5194/acp-6-3517-2006, 2006. Bartlett,~K B. and Harriss,~R C.: Review and assessment of methane emissions from wetlands, Chemosphere, 26, 261–320, \doi10.1016/0045-6535(93)90427-7, 1993. Baubron,~J., Allard,~P., and Toutain,~J.: Diffuse volcanic emissions of carbon dioxide from Vulcano Island, Italy, Nature, 344, 51–53, 1990. 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 \chemCH_4 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 F., Krol,~M., Dentener,~F., Wagner,~T., Platt,~U., Kaplan,~J O., Körner,~S., Heimann,~M., Dlugokencky,~E J., and Goede,~A.: Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: 2. Evaluation based on inverse model simulations, J. Geophys. Res., 112, 501–511, \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 V., Engel,~A., and Levin,~I.: Inverse modelling of global and regional \chemCH_4 emissions using SCIAMACHY satellite retrievals,~J. Geophys. Res., 114, D22301, \doi10.1029/2009JD012287, 2009. Bohn,~T J., Lettenmaier,~D P., Sathulur,~K., Bowling,~L C., Podest,~E., McDonald,~K., and Friborg,~T.: Methane emissions from Western Siberian wetlands: heterogeneity and sensitivity to climate change, Environ. Res. Lett., 2, 045015, \doi10.1088/1748-9326/2/4/045015, 2007. Börjesson,~G., Danielsson,~Å., and Svennson,~B H.: Methane fluxes from a~Swedish landfill determined by geostatistical treatment of static chamber measurements, Environ. Sci. Technol., 34, 4044–4050, 2000. Bovensmann,~H., Burrows,~J., Buchwitz,~M., Frerick,~J., Noël,~S., and Rozanov,~V.: SCIAMACHY: mission objectives and measurement modes, J. Atmos. Sci., 56, 127–150, 1999. Bovensmann, H., Buchwitz, M., Burrows, J. P., Reuter, M., Krings, T., Gerilowski, K., Schneising, O., Heymann, J., Tretner, A., and Erzinger, J.: A remote sensing technique for global monitoring of power plant \chemCO_2 emissions from space and related applications, Atmos. Meas. Tech., 3, 781–811, doi:10.5194/amt-3-781-2010, 2010. Bowen,~R G., Dallimore,~S R., and Côté,~M M.: Geomorphology and Gas Release from Pockmark Features in the Mackenzie Delta, Northwest Territories, Canada, Proceedings 9th International Conference on Permafrost, University of Alaska Fairbanks (http://www.nicop.org/), 1, 171–176, 2008. Bréon,~F.-M. and Ciais,~P.: Spaceborne remote sensing of greenhouse gas concentrations, C. R. Geosci., 342, 412–424, \doi10.1016/j.crte.2009.09.012, 2010. Buchwitz,~M., Rozanov,~V V., and Burrows,~J P.: A~near-infrared optimized DOAS method for the fast global retrieval of atmospheric \chemCH_4, CO, \chemCO_2, \chemH_2O, and \chemN_2O total column amounts from SCIAMACHY Envisat-1 nadir radiances,~J. Geophys. Res., 105, 15231–15245, 2000. Buchwitz, M., de Beek, R., Burrows, J. P., Bovensmann, H., Warneke, T., Notholt, J., Meirink, J. F., Goede, A. P. H., Bergamaschi, P., Körner, S., Heimann, M., and Schulz, A.: Atmospheric methane and carbon dioxide from SCIAMACHY satellite data: initial comparison with chemistry and transport models, Atmos. Chem. Phys., 5, 941–962, doi:10.5194/acp-5-941-2005, 2005a. Buchwitz, M., de Beek, R., No\"el, S., Burrows, J. P., Bovensmann, H., Bremer, H., Bergamaschi, P., Körner, S., and Heimann, M.: Carbon monoxide, methane and carbon dioxide columns retrieved from SCIAMACHY by WFM-DOAS: year 2003 initial data set, Atmos. Chem. Phys., 5, 3313–3329, doi:10.5194/acp-5-3313-2005, 2005b. Buchwitz, M., de Beek, R., No\"el, 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 \chemCH_4 and impact of calibration improvements on \chemCO_2 retrieval, Atmos. Chem. Phys., 6, 2727–2751, doi:10.5194/acp-6-2727-2006, 2006. Burlin,~Y K. and Sokolov,~B A.: Russian arctic sedimentary megabasin and its reflection in oil and gas propertries of its borderlands, Polarforschung, 69, 149–154, 2001. Burrows,~J P., Hölzle,~E., Goede,~A P H., Visser,~H., and Fricke,~W.: SCIAMACHY – Scanning Imaging Absorption Spectrometer for Atmospheric Chartography, Acta Astronaut., 35, 445–451, 1995. Chakraborty,~S K. and Anggraini,~J.: Massive mud flow and environmental damage following drilling failure – an example from Indonesia, Petrotech–2009, 11–15 January, P09-532, 11–15, 2009. Chambers,~A. and Strosher,~M.: DIAL Measurements of Fugitive Emissions from Natural Gas Plants and the Comparison with Emission Factor Estimates, 15th Annual Emission Inventory Conference, US Environmental Protection Agency New Orleans, 15–18 May, 2006a. Chambers,~A. and Strosher,~M.: Refinery Demonstration of Optical Technologies for Measurement of Fugitive Emissions and for Leak Detection, Final Report, Environment Canada, Ontario Ministry of the Environment and Alberta Environment, 2006b. Chen,~Y.-H. and Prinn,~R G.: Estimation of atmospheric methane emissions between 1996 and 2001 using a~three-dimensional global chemical transport model,~J. Geophys. Res., 111, D10307, \doi10.1029/2005JD006058, 2006. Chiodini,~G., Frondini,~F., and Raco,~B.: Diffuse emissions of \chemCO_2 from the Fossa crater, Vulcano Island (Italy), B. Volcanol., 58, 41–50, \doi10.1007/s004450050124, 1996. Crevoisier, C., Nobileau, D., Fiore, A. M., Armante, R., Chédin, A., and Scott, N. A.: Tropospheric methane in the tropics – first year from IASI hyperspectral infrared observations, Atmos. Chem. Phys., 9, 6337–6350, doi:10.5194/acp-9-6337-2009, 2009. Dimitrov,~L.: Contribution to atmospheric methane by natural seepages on the Bulgarian continental shelf, Cont. Shelf Res., 22, 2429–2442, \doi10.1016/S0278-4343(02)00055-9, 2002. Dlugokencky,~E J., Steele,~L P., Lang,~P M., and Masarie,~K A.: Atmospheric methane at Mauna Loa and Barrow observatories: presentation and analysis of in situ measurements,~J. Geophys. Res., 100, 23103–23113, 1995. Dlugokencky,~E J., Myers,~R C., Lang,~P M., Masarie,~K A., Crotwell,~A M., Thoning,~K W., Hall,~B D., Elkins,~J W., and Steele,~L P.: Conversion of NOAA atmospheric dry air \chemCH_4 mole fractions to a~gravimetrically prepared standard scale,~J. Geophys. Res., 110, D10307, \doi10.1029/2005JD006035, 2005. EPER: European Pollutant Emission Register 2004, http://eper.ec.europa.eu/, 2004. Ershov,~O.: Pergam-Suisse ALMA System Inspection of pipelines from helicopter in the North part of Italy – Report, Pergam-Suisse AG Talacker 42 Zürich 8001, Switzerland, 2007. Etiope,~G.: Natural emissions of methane from geological seepage in Europe, Atmos. Environ., 43, 1430–1443, \doi10.1016/j.atmosenv.2008.03.014, 2009. Etiope,~G., Feyzullayev,~A., Baciu,~C L., and Milkov,~A V.: Methane emission from mud volcanoes in Eastern Azerbaijan, Geology, 32, 465–468, \doi10.1130/G20320.1, 2004. Etiope,~G., Fridriksson,~T., Italiano,~F., Winiwarter,~W., and Theloke,~J.: Natural emissions of methane from geothermal and volcanic sources in Europe,~J. Volcanol. Geoth. Res., 165, 76–86, \doi10.1016/j.jvolgeores.2007.04.014, 2007. Etioppe,~G. and Klusman,~R W.: Geologic emissions of methane to the atmosphere, Chemosphere, 49(8), 777–789, \doi10.1016/S0045-6535(02)00380-6, 2002. Etioppe,~G. and Klusman,~R W.: New Directions: GEM – Geologic Emissions of Methane, the missing source in the atmospheric methane budget, Atmos. Environ., 38, 3099–3100, \doi10.1016/S0045-6535(02)00380-6, 2004. Fellner,~J., Schöngrundner,~P., and Brunner,~P H.: Methanemissionen aus Deponien – Bewertung von Messdaten (METHMES) (durchgeführt im Auftrag des Bundesministeriums für Land- und Forstwirtschaft, Umwelt und Wasserwirtschaft), Technische Universität Wien, Institut für Wassergüte und Abfallwirtschaft, Abteilung Abfallwirtschaft und Stoffhaushalt, A-1040 Wien, Karlsplatz 13/226.4, 2003. Frankenberg,~C., Meirink,~J., Weele,~M., Platt,~U., and Wagner,~T.: Assessing methane emissions from global space-borne observations, Science, 308, 1010–1014, \doi10.1126/science.1106644, 2005. Fung,~I., John,~J., Lerner,~J., Matthews,~E., Prather,~M., Steele,~L P., and Fraser,~P J.: Three-dimensional model synthesis of the global methane cycle,~J. Geophys. Res., 96, 13033–13065, 1991. Gramberg,~S., Kulakov,~Y N., Pogrebitsky,~Y E., and Sorokov,~D S.: Arcti Oil and Gas Super Basin, Worl Petroleum Congress, London, 93–99, 1983. IPCC, 2001: Climate Change 2001: The Scientific Basis, Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Houghton, J. T., Ding, Y., Griggs, D. J., Noguer, M., van der Linden, P. J., Dai, X., Maskell, K., and Johnson, C. A., Cambridge University Press, Cambridge, 881~pp, United Kingdom and New York, NY, USA, 2001. IPCC, 2007: Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, 996~pp., United Kingdom and New York, NY, USA, 2007. Italiano,~F., Pecoraino,~G., and Nuccio,~P M.: Steam output from fumaroles of an active volcano: tectonic and magmatic-hydrothermal controls on the degassing system at Vulcano (Aeolian arc),~J. Geophys. Res, 103, 29829–29842, \doi10.1029/98JB02237, 1998. Jagovkina,~S V., Karol,~I L., Zubov,~V A., Lagun,~V E., Reshetnikov,~A I., and Rozanov,~E V.: Reconstruction of the methane fluxes from the West Siberia gas fields by the 3-D regional chemical transport model, Atmos. Environ., 34, 5319–5328, \doi10.1016/S1352-2310(00)00347-2, 2000. Jagovkina,~S V., Karol,~I L., Zubov,~V A., Lagun,~V E., Reshetnikov,~A I., and Rozanov,~E V.: Methane fluxes in West Siberia: 3-D regional model simulation, Water, Air and Soil Poll., 1, 429–436, \doi10.1023/A:1013106011265, 2001. Judd,~A G.: Natural seabed gas seeps as sources of atmospheric methane, Environ. Geol., 46, 988–996, \doi10.1007/s00254-004-1083-3, 2004. Khalil,~M A K.: Atmospheric methane: an introduction, in: Atmospheric Methane: Its Role in the Global Environment, edited by: Khalil,~M A K., Springer, New York, 1–8, 2008. Kort,~E A., Eluszkiewicz,~J., Stephens,~B B., Miller,~J B., Gerbig,~C., Nehrkorn,~T., Daube,~B C., Kaplan,~J O., Houweling,~S., and Wofsy,~S C.: Emissions of \chemCH_4 and \chemN_2O over the United States and Canada based on a~receptororiented modeling framwork and COBRA-NA atmospheric observations, Geophys. Res. Lett., 35, L18808, \doi10.1029/2008GL034031, 2008. Krings,~T., Buchwitz,~M., Gerilowski,~K. et~al.: MAMAP – a~new spectrometer system for column-averaged methane and carbon dioxide observations from aircraft: retrieval algorithm and first inversions for point source emission rates, in preparation, 2010. Livingston,~W. and Wallace,~L.: An atlas of the solar spectrum in the infrared from 1850 to 9000 cm$^-1$ (1.1 to 5.4 μm), National Solar Observatory, Tech. rep. 91-001, 1991. Matsueda,~H. and Inoue,~H Y.: Aircraft measurements of trace gases between Japan and Singapore in October of 1993, 1996 and 1997, Geophys. Res. Lett., 26, 2413–2416, \doi10.1029/1999GL900089, 1999. Meyer,~O., Busack,~V., Haepe,~S., Theopold,~F., and Heimes,~F J.: HELPCOS The Helicopter Based Pipeline Control System of VGN – Verbundnetz AG, 23rd World Gas Conference, Amsterdam, 2006. Miller,~J B., Gatti,~L V., d'Amelio,~M T S., Crotwell,~A M., Dlugokencky,~E J., Bakwin,~P., Artaxo,~P., and Tans,~P P.: Airborne measurements indicate large methane emissions from the Eastern Amazon Basin, Geophys. Res. Lett., 34, L18808, \doi10.1029/2006GL029213, 2007. Mörner,~N.-A. and Etiope,~G.: Carbon degassing from the lithosphere, Global Planet. Change, 33, 185–203, \doi10.1016/S0921-8181(02)00070-X, 2002. Nisbet,~E.: Methane Monitoring in the European region – MethMonitEUr, EC contract EVK2-CT-2002-00175, Coordinator: Euan Nisbet, Final Report, 2005. Oberlander,~E A., Brenninkmeijer,~C A M., Crutzen,~P J., Elansky,~N F., Golitsyn,~G., Granberg,~I G., Scharffe,~D., Hofmann,~R., Belikov,~I B., Paretzke,~H G., and van Velthoven,~P F J.: Trace gas measurements along the Trans-Siberian railroad: the TROICA~5 expedition,~J. Geophys. Res., 107, 4206, \doi10.1029/2001JD000953, 2002. Rice,~A L., Tyler,~S C., McCarthy,~M C., Boering,~K A., and Atlas,~E.: Carbon and hydrogen isotopic compositions of stratospheric methane: 1. High-precision observations from the NASA ER-2 aircraft,~J. Geophys. Res., 108, 4206, \doi10.1029/2002JD003042, 2003. Roberts,~D A., Bradley,~E S., Cheung,~R., Leifer,~I., Dennison,~P E., and Margolis,~J S.: Mapping methane emissions from a~marine geological seep source using imaging spectrometry, Remote Sens. Environ., 114, 592–606, \doi10.1016/j.rse.2009.10.015, 2010. Rothman,~L., Jaquemart,~D., Barbe,~A., Benner,~D C., Birk,~M., Brown,~L., Carleer,~M., Jr,~C C., Chance,~K., Coudert,~L., Dana,~V., Devi,~V., Flaud,~J.-M., Gamache,~R., Goldman,~A., Hartmann,~J.-M., Jucks,~K., Makim,~A., Mandin,~J.-Y., Massie,~S., Orphalh,~J., Perrin,~A., Rinsland,~C., Smith,~M., Tennyson,~J., Tolchenov,~R., Toth,~R., Auwera,~J V., Varanasi,~P., and Wagner,~G.: The Hitran 2004 molecular spectroscopic database, J. Quant. Spectrosc. Ra., 96, 139–204, \doi10.1016/j.jqsrt.2004.10.008, 2005. Rozanov,~A., Rozanov,~V., Buchwitz,~M., Kokhanovsky,~A., and Burrows,~J.: SCIATRAN 2.0 – a~new radiative transfer model for geophysical applications in the 175–2400 nm spectral region, Adv. Space Res., 36, 1015–1019, \doi10.1016/j.asr.2005.03.012, 2005. Sachs,~T., Giebels,~M., Wille,~C., Kutzbach,~L., and Boike,~J.: Methane Emissions from Siberian Wet Polygonal Tundra on Multiple Spatial Scales: Vertical Flux Measurements by Closed Chambers and Eddy Covariance, Samoylov island, Lena River Delta, Proceedings of the 9th International Conference on Permafrost, University of Alaska, Fairbanks, 29 June–3 July, 1549–1554, 2008. Schneising,~O.: Analysis and interpretation of satellite measurements in the near-infrared spectral region: atmospheric carbon dioxide and methane, PhD thesis,, University of Bremen, Institute of Environmental Physics (IUP), Germany, 2009. Schneising, O., Buchwitz, M., Burrows, J. P., Bovensmann, H., Reuter, M., Notholt, J., Macatangay, R., and Warneke, T.: Three years of greenhouse gas column-averaged dry air mole fractions retrieved from satellite – Part 1: Carbon dioxide, Atmos. Chem. Phys., 8, 3827–3853, doi:10.5194/acp-8-3827-2008, 2008. 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. Shakhova,~N., Semiletov,~I., Salyuk,~A., Yusupov,~V., Kosmach,~D., and Gustafsson,~Ö.: Extensive methane venting to the atmosphere from sediments of the East Siberian arctic shelf, Science, 327, 1246–1250, \doi10.1126/science.1182221, 2010. Shakhova,~N E., Semiletov,~I P., Salyuk,~A N., Bel'cheva,~N N., and Kosmach,~D A.: Methane anomalies in the near-water atmospheric layer above the shelf of East Siberian arctic shelf, Dokl. Earth Sci., 415, 764–768, \doi10.1134/S1028334X07050236, 2007. Siddique,~T., Gupta,~R., Fedorak,~P M., MacKinnon,~M D., and Foght,~J M.: A~first approximation kinetic model to predict methane generation from an oil sands tailings settling basin, Chemosphere, 72, 1573–1580, \doi10.1016/j.chemosphere.2008.04.036, 2008. Suto,~H., Kuze,~A., Nakajima,~M., Hamazaki,~T., Yokota,~T., and Inoue,~G.: Airborne SWIR FTS for GOSAT validation and calibration (Proceedings Paper), SPIE Proceedings, 7106, 1060M, \doi10.1117/12.799963, 2008. Takeuchi,~W., Tamura,~M., and Yasuoka,~Y.: Estimation of methane emission from West Siberian wetland by scaling technique between NOAA AVHRR and SPOT HRV, Remote Sens. Environ., 85, 21–29, \doi10.1016/S0034-4257(02)00183-9, 2003. Villani, M. G., Bergamaschi, P., Krol, M., Meirink, J. F., and Dentener, F.: Inverse modeling of European \chemCH_4 emissions: sensitivity to the observational network, Atmos. Chem. Phys., 10, 1249–1267, doi:10.5194/acp-10-1249-2010, 2010. Walter,~K M., Zimov,~S A., Chanton,~J P., Verbyla,~D., and Chapin III,~F S.: Methane bubbling from Siberian thaw lakes as a~positive feedback to climate warming, Science, 443, 71–75, \doi10.1038/nature05040, 2006. Walter,~K M., Smith,~L C., and Chapin III,~F S.: Methane bubbling from northern lakes: present and future contributions to the global methane budget, Philos. T. Roy. Soc. A, 365, 1657–1676, \doi10.1098/rsta.2007.2036, 2007. Watson,~R T., Rohde,~H., Oescherger,~H., and Siegenthaler,~U.: Greenhouse gases and aerosols, in: Climate Change: The Intergovernmental Panel on Climate Change Scientific Assessment, edited by: Houghton,~J T., Jenkins,~G J., and Ephraumus,~J J., Cambridge University Press, Cambridge University Press, Cambridge, 1–40, 1990. Winderlich, J., Chen, H., Höfer, A., Gerbig, C., Seifert, T., Kolle, O., Kaiser, C., Lavrič, J. V., and Heimann, M.: Continuous low-maintenance \chemCO_2/CH_4/H_2O measurements at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia, Atmos. Meas. Tech. Discuss., 3, 1399–1437, doi:10.5194/amtd-3-1399-2010, 2010. Wuebbles,~D J. and Hayhoe,~K.: Atmospheric methane and global change, Earth-Sci. Rev., 57, 177–210, \doi10.1016/S0012-8252(01)00062-9, 2002. Yoshida,~J., Kawashima,~T., Ishida,~J., Hamada,~K., Tanii,~J., Katsuyama,~Y., Suto,~H., Kuze,~A., Nakajima,~M., and Hamazaki,~T.: Prelaunch performance test results of TANSO-FTS and CAI on GOSAT (Proceedings Paper), Proc. SPIE, 7082, \doi10.1117/12.800701, 2008. Zimig,~W. and Ulbricht,~M.: CHARM® – The dawn of a~new era in checking the tightness of natural gas pipelines, 23rd World Gas Conference, Amsterdam, 2006.