References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-11-13287-2011

The isotopic composition of methane in the stratosphere: high-altitude balloon sample measurements

Röckmann

¹ ² Brass

¹ ² Borchers

³ Engel

⁴

Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, The Netherlands

Atmospheric Physics Division, Max Planck Institute for Nuclear Physics, Heidelberg, Germany

Planets and Comets Department, Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany

Institute for Atmospheric and Environmental Sciences, J. W. Goethe University, Frankfurt, Germany

21 12 2011

11 24 13287 13304

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/11/13287/2011/acp-11-13287-2011.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/13287/2011/acp-11-13287-2011.pdf

The isotopic composition of stratospheric methane has been determined on a large suite of air samples from stratospheric balloon flights covering subtropical to polar latitudes and a time period of 16 yr. 154 samples were analyzed for δ13C and 119 samples for δD, increasing the previously published dataset for balloon borne samples by an order of magnitude, and more than doubling the total available stratospheric data (including aircraft samples) published to date. The samples also cover a large range in mixing ratio from tropospheric values near 1800 ppb down to only 250 ppb, and the strong isotope fractionation processes accordingly increase the isotopic composition up to δ13C = −14&permil; and δD = +190&permil;, the largest enrichments observed for atmospheric CH4 so far. When analyzing and comparing kinetic isotope effects (KIEs) derived from single balloon profiles, it is necessary to take into account the residence time in the stratosphere in combination with the observed mixing ratio and isotope trends in the troposphere, and the range of isotope values covered by the individual profile. The isotopic composition of CH4 in the stratosphere is affected by both chemical and dynamical processes. This severely hampers interpretation of the data in terms of the relative fractions of the three important sink mechanisms (reaction with OH, O(1D) and Cl). It is shown that a formal sink partitioning using the measured data severely underestimates the fraction removed by OH, which is likely due to the insensitivity of the measurements to the kinetic fractionation in the lower stratosphere. Full quantitative interpretation of the CH4 isotope data in terms of the three sink reactions requires a global model.

References 1

Andrews, A. E., Boering, K. A., Wofsy, S. C., Daube, B. C., Jones, D. B., Alex, S., Loewenstein, M., Podolske, J. R., and Strahan, S. E.: Empirical age spectra for the midlatitude lower stratosphere from in situ observations of CO2: Quantitative evidence for a subtropical "barrier" to horizontal transport, J. Geophys. Res., 106, 10257–10274, 2001.

Avallone, L. M. and Prather, M. J.: Photochemical evolution of ozone in the lower tropical stratosphere, J. Geophys. Res., 101, 1457–1461, 1996.

Bergamaschi, P., Brühl, C., Brenninkmeijer, C. A. M., Saueressig, G., Crowley, J. N., Grooss, J. U., Fischer, H., and Crutzen, P. J.: Implications of the large carbon kinetic isotope effect in the reaction CH4+Cl for the $^13$C/$^12$C ratio of stratospheric CH4, Geophys. Res. Lett., 23, 2227–2230, 1996.

Bergamaschi, P., Brenninkmeijer, C. A. M., Hahn, M., Röckmann, T., Scharffe, D. H., Crutzen, P. J., Elansky, N. F., Belikov, I. B., Trivett, N. B. A., and Worthy, D. E. J.: Isotope analysis based source identification for atmospheric CH4 and CO across Russia using the Trans-Siberian railroad, J. Geophys. Res., 103, 8227–8235, 1998.

Bergamaschi, P., Bräunlich, M., Marik, T., and Brenninkmeijer, C. A. M.: Measurements of the carbon and hydrogen isotopes of atmospheric methane at Izana, Tenerife: Seasonal cycles and synoptic-scale variations, J. Geophys. Res., 105, 14531–14546, 2000.

Bergamaschi, P., Lowe, D. C., Manning, M. R., Moss, R., Bromley, T., and Clarkson, T. S.: Transects of atmospheric CO, CH4, and their isotopic composition across the Pacific: Shipboard measurements and validation of inverse models, J. Geophys. Res., 106, 7993–8011, 2001.

Birner, T. and Bönisch, H.: Residual circulation trajectories and transit times into the extratropical lowermost stratosphere, Atmos. Chem. Phys., 11, 817–827, http://dx.doi.org/10.5194/acp-11-817-2011doi:10.5194/acp-11-817-2011, 2011.

Bönisch, H., Engel, A., Birner, Th., Hoor, P., Tarasick, D. W., and Ray, E. A.: On the structural changes in the Brewer-Dobson circulation after 2000, Atmos. Chem. Phys., 11, 3937–3948, http://dx.doi.org/10.5194/acp-11-3937-2011doi:10.5194/acp-11-3937-2011, 2011.

Boering, K. A., Wofsy, S. C., Daube, B. C., Schneider, H. R., Loewenstein, M., and Podolske, J. R.: Stratospheric mean ages and transport rates from observations of carbon dioxide and nitrous oxide, Science, 274, 1340–1343, 1996.

Brass, M. and Röckmann, T.: Continuous-flow isotope ratio mass spectrometry method for carbon and hydrogen isotope measurements on atmospheric methane, Atmos. Meas. Tech., 3, 1707–1721, http://dx.doi.org/10.5194/amt-3-1707-2010doi:10.5194/amt-3-1707-2010, 2010.

Brenninkmeijer, C. A. M., Lowe, D. C., Manning, M. R., Sparks, R. J., and Velthoven, P. F. J. v.: The $^13$C, $^14$C, and $^18$O isotopic composition of CO, CH4 and CO2 in the higher southern latitudes lower stratosphere, J. Geophys. Res., 100, 26163–26172, 1995.

Brenninkmeijer, C. A. M., Müller, R., Crutzen, P. J., Lowe, D. C., Manning, M. R., Sparks, R. J., and Velthoven, P. J. v.: A large$^ 13$CO deficit in the lower Antarctic stratosphere due to "ozone hole" chemistry: Part 1, observations, Geophys. Res. Lett., 23, 2125–2128, 1996.

Brewer, A. W.: Evidence for a world circulation provided by the measurements of helium and water vapour distribution in the stratosphere, Q. J. Roy. Meteorol. Soc., 75, 351–363, 1949.

Dlugokencky, E. J., Masarie, K. A., Lang, P. M., and Tans, P. P.: Continuing decline in the growth rate of the atmospheric methane burden, Nature, 393, 447–450, 1998.

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 CH4 mole fractions to a gravimetrically prepared standard scale, J. Geophys. Res., 110, D18306, doi:18310.11029/12005jd006035, 2005.

Dobson, G. M. B., Brewer, A. W., and Cwilong, B. M.: Meteorology of the lower stratosphere, P. Roy. Soc London Ser-A, 185, 144–175, 1946.

Engel, A., Möbius, T., Haase, H.-P., Bönisch, H., Wetter, T., Schmidt, U., Levin, I., Reddmann, T., Oelhaf, H., Wetzel, G., Grunow, K., Huret, N., and Pirre, M.: Observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003, Atmos. Chem. Phys., 6, 267–282, http://dx.doi.org/10.5194/acp-6-267-2006doi:10.5194/acp-6-267-2006, 2006.

Erikson, E.: Deuterium and oxygen-18 in precipitation and other natural waters: Some theoretical considerations, Tellus, 17, 498–512, 1965.

Gierzak, T., Talukdar, R. K., Herndon, S. C., Vaghjiani, G. L., and Ravishankara, A. R.: Rate coefficients for reactions of hydroxyl radicals with methane and deuterated methanes, J. Phys. Chem., 101, 3125–3134, 1997.

Griffith, D. W. T., Toon, G. C., Sen, B., Blavier, J.-F., and Toth, R. A.: Vertical profiles of nitrous oxide isotopomer fractionation measured in the stratosphere, Geophys. Res. Lett., 27, 2485–2488, 2000.

Gupta, M., Tyler, S., and Cicerone, R.: Modeling atmospheric $\delta ^13$CH4 and the causes of recent changes in atmospheric CH4 amounts, J. Geophys. Res., 101, 22923–22932, 1996.

Hall, T. M. and Plumb, R. A.: Age as a diagnostic of stratospheric transport, J. Geophys. Res., 99, 1059–1070, 1994.

Holton, J. R.: A dynamically based transport parameterization for one-dimensional photochemical models of the stratosphere, J. Geophys. Res., 91, 2681–2686, http://dx.doi.org/10.1029/JD091iD02p02681doi:10.1029/JD091iD02p02681, 1986.

Irion, F. W., Moyer, E. J., Gunson, M. R., Rinsland, C. P., Yung, Y. L., Michelsen, H. A., Salawitch, R. J., Chang, A. Y., Newchurch, M. J., Abbas, M. M., Abrams, M. C., and Zander, R.: Stratospheric observations of CH3D and HDO from ATMOS infrared solar spectra: Enrichments of deuterium in methane and implications for HD, Geophys. Res. Lett., 23, 2381–2384, 1996.

Kaiser, J., Brenninkmeijer, C. A. M., and Röckmann, T.: Intramolecular $^15$N and $^18$O fractionation in the reaction of N2O with O($^1$D) and its implications for the stratospheric N2O isotope signature, J. Geophys. Res., 107, 4214, http://dx.doi.org/10.1029/2001JD001506doi:10.1029/2001JD001506, 2002a.

Kaiser, J., Röckmann, T., and Brenninkmeijer, C. A. M.: Temperature dependence of isotope fractionation in N2O photolysis, Phys. Chem. Chem. Phys., 4, 4420–4430, doi:4410.1039/b204837j, 2002b.

Kaiser, J., Engel, A., Borchers, R., and Röckmann, T.: Probing stratospheric transport and chemistry with new balloon and aircraft observations of the meridional and vertical N2O isotope distribution, Atmos. Chem. Phys., 6, 3535–3556, http://dx.doi.org/10.5194/acp-6-3535-2006doi:10.5194/acp-6-3535-2006, 2006.

Kaye, J. A.: Mechanisms and observations for isotope fractionation of molecular-species in planetary atmospheres, Rev. Geophys., 25, 1609–1658, 1987.

Keppler, F., Hamilton, J. T. G., Brass, M., and Röckmann, T.: Methane emissions from terrestrial plants under aerobic conditions, Nature, 439, 187–191, doi:110.1038/nature04420, 2006.

Keppler, F., Hamilton, J. T. G., McRoberts, W. C., Vigano, I., Brass, M., and Röckmann, T.: Methoxyl groups of plant pectin as a precursor of atmospheric methane: evidence from deuterium labelling studies, New Phytol., 178, 808–814, 2008.

Kida, H.: General-circulation of air parcels and transport characteristics derived from a hemispheric GCM, 2. Very long-term motions of air parcels in the troposphere and stratosphere, J. Meteorol. Soc. Jap., 61, 510–522, 1983.

Lowe, D. C., Manning, M. R., Brailsford, G. W., and Bromley, A. M.: The 1991–1992 atmospheric methane anomaly: Southern hemisphere C-13 decrease and growth rate fluctuations, Geophys. Res. Lett., 24, 857–860, 1997.

Mahlman, J. D., Levy II, H., and Moxim, W. J.: Three-dimensional simulations of stratospheric N2O: Predictions for other trace constituents., J. Geophys. Res., 91, 2687–2707. (Correction, J. Geophys. Res., 2691, 9921, http://dx.doi.org/10.1029/JD091iD02p02687doi:10.1029/JD091iD02p02687, 1986.

McCarthy, M. C., Connell, P., and Boering, K. A.: Isotopic fractionation of methane in the stratosphere and its effect on free tropospheric isotopic compositions, Geophys. Res. Lett., 28, 3657–3660, 2001.

McCarthy, M. C., Boering, K. A., Rice, A. L., Tyler, S. C., Connell, P., and Atlas, E.: Carbon and hydrogen isotopic compositions of stratospheric methane: 2. Two-dimensional model results and implications for kinetic isotope effects, J. Geophys. Res., 108, 4461, http://dx.doi.org/10.1029/2002JD003183doi:10.1029/2002JD003183, 2003.

Michelsen, H. A., Manney, G. L., Gunson, M. R., Rinsland, C. P., and Zander, R.: Correlations of stratospheric abundances of CH4 and N2O derived from ATMOS measurements, Geophys. Res. Lett., 25, 2777–2780, 1998.

Miller, J. B., Mack, K. A., Dissly, R., White, J. W. C., Dlugokencky, E. J., and Tans, P. P.: Development of analytical methods and measurements of $^13$C/$^12$C in atmospheric CH4 from the NOAA/CMDL global air sampling network, J. Geophys. Res., 107, 4178, doi:4110.1029/2001JD000630, 2002.

Neu, J. L. and Plumb, R. A.: Age of air in a "leaky pipe" model of stratospheric transport, J. Geophys. Res., 104, 19243–19255, 1999.

Park, S. Y., Atlas, E. L., and Boering, K. A.: Measurements of N2O isotopologues in the stratosphere: Influence of transport on the apparent enrichment factors and the isotopologue fluxes to the troposphere, J. Geophys. Res., 109, D01305, doi:01310.01029/02003JD003731, 2004.

Plumb, R. A.: A "tropical pipe" model of stratospheric transport, J. Geophys. Res., 101, 3957–3972, 1996.

Plumb, R. A. and Ko, M. K. W.: Interrelationships between mixing ratios of long lived stratospheric constituents, J. Geophys. Res., 97, 10145–10156, 1992.

Plumb, R. A., Waugh, D. W., and Chipperfield, M. P.: The effects of mixing on traces relationships in the polar vortices, J. Geophys. Res., 105, 10047–10062, 2000.

Quay, P., Stutsman, J., Wilbur, D., Snover, A., Dlugokencky, E., and Brown, T.: The isotopic composition of atmospheric methane, Global Biogeochem. Cy., 13, 445–461, 1999.

Rahn, T., Zhang, H., Wahlen, M., and Blake, G. A.: Stable isotope fractionation during ultraviolet photolysis of N2O, Geophys. Res. Lett., 25, 4489–4492, 1998.

Rice, A. L., Gotoh, A. A., Ajie, H. O., and Tyler, S. C.: High-precision continuous-flow measurement of $\delta ^13$C and $\delta D$ of atmospheric CH4, Anal. Chem., 73, 4104–4110, 2001.

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, 4460, http://dx.doi.org/10.1029/2002JD003042doi:10.1029/2002JD003042, 2003.

Ridal, M. and Siskind, D. E.: A two-dimensional simulation of the isotopic composition of water vapor and methane in the upper atmosphere, J. Geophys. Res., 107, 4807, doi:4810.1029/2002JD002215, 2002.

Röckmann, T., Kaiser, J., Brenninkmeijer, C. A. M., Crowley, J. N., Borchers, R., Brand, W. A., and Crutzen, P. J.: Isotopic enrichment of nitrous oxide ($^15$N$^14$NO, $^14$N$^15$NO, $^14$N$^14$N$^18$O) in the stratosphere and in the laboratory, J. Geophys. Res., 106, 10403–10410, 2001.

Saueressig, G., Bergamaschi, P., Crowley, J. N., Fischer, H., and Harris, G. W.: Carbon kinetic isotope effect in the reaction of CH4 with Cl atoms, Geophys. Res. Lett., 22, 1225–1228, 1995.

Saueressig, G., Bergamaschi, P., Crowley, J. N., Fischer, H., and Harris, G. W.: D/H kinetic isotope effect in the reaction CH4 + Cl, Geophys. Res. Lett., 23, 3619–3622, 1996.

Saueressig, G., Crowley, J. N., Bergamaschi, P., Brühl, C., Brenninkmeijer, C. A. M., and Fischer, H.: Carbon 13 and D kinetic isotope effects in the reactions of CH4 with O($^1$D) and OH: New laboratory measurements and their implications for the isotopic composition of stratospheric methane, J. Geophys. Res., 106, 23127–23138, 2001.

Schmidt, U., Kulessa, G., Klein, E., Roth, E. P., Fabian, P., and Borchers, R.: Intercomparison of balloon-borne cryogenic whole air samplers during the Map-Globus 1983 campaign, Planet. Space Sci., 35, 647–656, 1987.

Simpson, I. J., Blake, D. R., Rowland, F. S., and Chen, T. Y.: Implications of the recent fluctuations in the growth rate of tropospheric methane, Geophys. Res. Lett., 29, 1479, http://dx.doi.org/10.1029/2001GL014521doi:10.1029/2001GL014521, 2002.

Stevens, C. M. and Rust, F. E.: The carbon isotopic composition of atmospheric methane, J. Geophys. Res., 87, 4879–4882, 1982.

Sugawara, S., Nakazawa, T., Shirakawa, Y., Kawamura, K., and Aoki, S.: Vertical profile of the carbon isotopic ratio of stratospheric methane over Japan, Geophys. Res. Lett., 24, 2989–2992, 1997.

Tarasova, O. A., Brenninkmeijer, C. A. M., Assonov, S. S., Elansky, N. F., Röckmann, T., and Brass, M.: Atmospheric CH4 along the Trans-Siberian railroad (TROICA) and river Ob: Source identification using stable isotope analysis, Atmos. Environ., 40, 5617–5628, 2006.

Toyoda, S., Yoshida, N., Urabe, T., Aoki, S., Nakazawa, T., Sugawara, S., and Honda, H.: Fractionation of N2O isotopomers in the stratosphere, J. Geophys. Res., 106, 7515–7522, 2001.

Tyler, S. C., Ajie, H. O., Gupta, M. L., Cicerone, R. J., Blake, D. R., and Dlugokencky, E. J.: Stable carbon isotopic composition of atmospheric methane: A comparison of surface level and free tropospheric air, J. Geophys. Res., 104, 13895–13910, 1999.

Vigano, I., Röckmann, T., Holzinger, R., van Dijk, A., Keppler, F., Greule, M., Brand, W. A., Geilmann, H., and van Weelden, H.: The stable isotope signature of methane emitted from plant material under UV irradiation, Atmos. Environ., 43, 5637–5646, doi:5610.1016/j.atmosenv.2009.5607.5046, 2009.

Vigano, I., Holzinger, R., Keppler, F., Greule, M., Brand, W. A., Geilmann, H., van Weelden, H., and Röckmann, T.: Water drives the deuterium content of the methane emitted from plants, Geochim. Cosmochim. Act., 74, 3865–3873, 2010.

Volk, C. M., Elkins, J. W., Fahey, D. W., Dutton, G. S., Gilligan, J. M., Loewenstein, M., Podolske, J. R., Chan, K. R., and Gunson, M. R.: Quantifying transport between the tropical and mid-latitude lower stratosphere, Science, 272, 1763–1768, 1996.

Wahlen, M.: The Global Methane Cycle, Annu. Rev. Earth Planet. Sci., 21, 407–426, 1993.

Wahlen, M., Tanaka, N., Henty, R., Deck, B., Zeglen, J., Vogel, J. S., Southon, J., Shemesh, A., Fairbanks, R., and Broecker, W.: Carbon-14 in methane sources and in atmospheric methane: The contribution from fossil carbon, Science, 245, 286–290, 1989.

Wang, J. S., McElroy, M. B., Spivakovsky, C. M., and Jones, D. B. A.: On the contribution of anthropogenic Cl to the increase in $\delta ^13$C of atmospheric methane, Global Biogeochem. Cy., 16, 1047, doi:1010.1029/2001GB001572, 2002.

Waugh, D. W. and Rong, P. P.: Interannual variability in the decay of lower stratospheric Arctic vortices, J. Meteorol. Soc. Japan, 80, 997–1012, 2002.

Waugh, D. W., Plumb, R. A., Elkins, J. W., Fahey, D. W., Boering, K. A., Dutton, G. S., Volk, C. M., Keim, E., Gao, R. S., Daube, B. C., Wofsy, S. C., Loewenstein, M., Podolske, J. R., Chan, K. R., Proffitt, M. H., Kelly, K., Newman, P. A., and Lait, L. R.: Mixing of polar vortex air into middle latitudes as revealed by tracer-tracer scatterplots, J. Geophys. Res., 102, 13119–13134, 1997.

WMO: (World Meteorological Organization), Scientific assessment of ozone depletion: 2002, Global Ozone Research and Monitoring Project, Report Nr 47, Geneva, 498 pp., 2003.

Zahn, A., Franz, P., Bechtel, C., Grooß, J.-U., and Röckmann, T.: Modelling the budget of middle atmospheric water vapour isotopes, Atmos. Chem. Phys., 6, 2073–2090, http://dx.doi.org/10.5194/acp-6-2073-2006doi:10.5194/acp-6-2073-2006, 2006.