Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 9 21 2009 10.5194/acp-9-8365-2009 http://www.atmos-chem-phys.net/9/8365/2009/ http://www.atmos-chem-phys.net/9/8365/2009/acp-9-8365-2009.html http://www.atmos-chem-phys.net/9/8365/2009/acp-9-8365-2009.pdf 8365 8375 2009-11-03 Eddy covariance methane measurements at a Ponderosa pine plantation in California C. J. P. P. Smeets c.j.p.p.smeets@uu.nl R. Holzinger I. Vigano A. H. Goldstein T. Röckmann Institute for Marine and Atmospheric research Utrecht, Princetonplein 5, 3584 CC, Utrecht, The Netherlands University of California, Berkeley, Department of Environmental Science, Policy and management, USA Long term methane flux measurements have been mostly performed with plant or soil enclosure techniques on specific components of an ecosystem. New fast response methane analyzers make it possible to use the eddy covariance (EC) technique instead. The EC technique is advantageous because it allows continuous flux measurements integrating over a larger and more representative area including the complete ecosystem, and allows fluxes to be observed as environmental conditions change naturally without disturbance. We deployed the closed-path Fast Methane analyzer (FMA) from Los Gatos Research Ltd and demonstrate its performance for EC measurements at a Ponderosa pine plantation at the Blodgett Forest site in central California. The fluctuations of the CH₄ concentration measured at 10 Hz appear to be small and their standard deviation is comparable to the magnitude of the signal noise (±5 ppbv). Consequently, the power spectra typically have a white noise signature at the high frequency end (a slope of +1). Nevertheless, in the frequency range important for turbulent exchange, the cospectra of CH₄ compare very well with all other scalar cospectra confirming the quality of the FMA measurements are good for the EC technique. We furthermore evaluate the complications of combined open and closed-path measurements when applying the Webb-Pearman-Leuning (WPL) corrections (Webb et al., 1980) and the consequences of a phase lag between the water vapor and methane signal inside the closed path system. The results of diurnal variations of CH₄ concentrations and fluxes are summarized and compared to the monthly results of process-based model calculations. Aubinet, M., Grell, A., Ibrom, A., Rannik, Ãœ., Moncrieff, J., et al.: Estimates of the annual net carbon and water exchange of european forests: the euroflux methodology, Adv. Ecol. Res., 30, 113–175, 2000. Aubinet, M., Chermanne, B., Vandenhaute, M., Longdoz, B., Yernaux, M., and Laitat, E.: Long term carbon dioxide exchange above a mixed forest in the belgain ardennes, Agric Forest Meteorol., 108, 293–315, 2001. Braga~do Carmo, J., Keller, M., Dezincourt~Dias, J., Barbaso~de Camargo, P., and Crill, P.: A source of methane from the upland forests in the brazilian amazon, Geophys. Res. Lett., 33, L04809, doi:10.1029/2005GL025436, 2006. Carroll, J. J. and Dixon, A. J.: Regional scale transport over complex terrain, a case study: tracing the sacramento plume in the sierra nevada of california, Atmos. Environ., 36(23), 3745–3758, 2002. Clement, R.: Mass and energy exchange of a plantation forest in scotland using micrometeorological methods, PhD thesis, The University of Edinburgh, 597 pp., 2004. Dillon, M., Lamanna, M., Schade, G., Goldstein, A., and Cohen, R.: Chemical evolution of the sacramento urban plume: Transport and oxidation, J. Geophys. Res., 107(D5), 4045, doi:10.1029/2001JD000969, 2002. Dutaur, L. and Verchot, L. V.: A global inventory of the soil ch₄ sink, Global Biogeochem. Cycles, 21, GB4013, doi:10.1029/2006GB002734, 2007. Frankenberg, C., Meirink, J. F., Van~Weels, M., Platt, U., and Wagner, T.: Assessing methane emissions from global space-borne obervations, Science, 308, 1010–1014, doi:10.1126/science.1106,644, 2005. Fritschen, L. J. and Gay, L. W.: Environmental Instrumentation. Springer-Verlag, New York, 216 pp., 1979. Goldstein, A., Hultman, N., Fracheboud, J., Bauer, M., Panek, J., Xu, M., Qi, Y., Guenther, A., and Baugh, W.: Effects of climate variability on the carbon dioxide, water, and sensible heat fluxes above a ponderosa pine plantation in the sierra nevada (ca), Agric. Forest Meteorol., 101(2–3), 113–129, 2000. Hendriks, D. M. D., Dolman, A. J., van der Molen, M. K., and van Huissteden, J.: A compact and stable eddy covariance set-up for methane measurements using off-axis integrated cavity output spectroscopy, Atmos. Chem. Phys., 8, 431–443, 2008. Ibrom, A., Dellwik, E., Ejling~Larsen, S., and Pilegaard, K.: On the use of the webb-pearman-leuning theory for closed-path eddy correlation measurements, Tellus, 59B, 937–946, 2007a. Ibrom, A., Dellwik, E., Flyvbjerg, H., Jensen, N. O., and Pilegaard, K.: Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation systems, Agric. For. Meteorol., 147, 140–156, 2007b. IPCC: IPCC Fourth Assessment Report, Climate Change 2007, Cambridge University Press, Cambridge, 996 pp., 2007. Kaimal, J. C.: Turbulence spectra, length scales and structure parameters in the stable surface layer, Bound. Lay. Meteorol., 4, 289–309, 1973. Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Coté, O. R.: Spectral characteristics of surface layer turbulence, Q. J. Roy. Meteorol. Soc., 98, 653–689, 1972. Keppler, F., Hamilton, J., Braß, M., and Röckmann, T.: Methane emissions from terrestrial plants under aerobic conditions, Nature, 439, 187–191, doi:10.1038/nature04,420, 2005. Keppler, T., Hamilton, J., McRoberts, W., Vigano, I., Braß, M., and Röckmann, T.: Methoxyl groups of plant pectin as a precursor of atmospheric methane: evidence from deuterium labelling studies, New Phytologist 178, 808–814, doi:10.111/j.1469–8373.2008.02,411.x, 2008. Kiese, R., Hewett, B., and Graham, A.: Seasonal variability of n₂o emissions and ch₄ uptake from tropical rainforest siols of queensland, australia, Global Biogeochem. Cycles, 17(2), 1043, doi:10.1029/2002GB00214, 2003. Kroon, P. S., Hensen, A., Jonker, H. J. J., Zahniser, M. S., van't Veen, W. H., and Vermeulen, A. T.: Suitability of quantum cascade laser spectroscopy for CH₄ and N₂O eddy covariance flux measurements, Biogeosciences, 4, 715–728, 2007. Kutzbach, L., Schneider, J., Sachs, T., Giebels, M., Nykänen, H., Shurpali, N. J., Martikainen, P. J., and Wilmking, M.: Co₂ flux determination by closed-chamber methods can be seriously biased by inappropriate application of linear regression, Biogeochem., 4, 1005–1025, 2007. Lamanna, M. and Goldstein, A.: In-situ measurements of c2-c10 vocs above a sierra nevada ponderosa pine plantation, J. Geophys. Res., 104(D17), 21247–21262, 1999. Laubach, J. and Teichmann, U.: Measuring energy budget components by eddy correlation: Data corrections and application over low vegetation, Beitr. Phys. Atmos., 69(2), 307–320, 1996. Lenschow, D. H. and Raupach, M. R.: The attenuation of fluctuations in scalar concentrations through sampling tubes, J. Geophys. Res., 96, 15259–15268, 1991. Leuning, R. and King, K. M.: Comparison of eddy-covarariance measurements of co₂ fluxes by open- and closed-path co₂ analysers, Bound. Lay. Meteorol., 59, 297–311, 1992. Leuning, R. and Moncrieff, J.: Eddy-covariance co₂ measurements using open- and closed path co₂-analysers: correctionsfor analyser water vaapour sensitivity and damping of fluctuations in air sampling tubes, Bound. Lay. Meteorol., 53, 63–76, 1990. Massman, W. J.: Concerning the measurement of atmospheric trace gas fluxes with open- and closed-path eddy covariance systems: the wpl terms and spectral attenuation, in: Handbook of micrometeorology, edited by: Lee, X., Massman, W. J., and Law, B., Atmospheric and Oceanographic Sciences Library, Kluwer Academic Publishers, pp 133–160, 2004. Miller, J. B., Gatti, L. V., D'Amelio, M. T. S., Crotwell, A. M., Dlugokencky, E. J., Bakwin, P., Artaxo, P. P., and~Tans, P.: Airborne measurements indicate large methane emissions from the eastern amazon basin, Geophys. Res. Lett., 34, L10809, doi:10.1029/2006GL029213, 2007. Misson, L., Tang, J., Xu, M., McKay, M., and Goldstein, A.: Influences of recovery from clear-cut, climate variability, and thinning on the carbon balance of a young ponderosa pine plantation, Agric. Forest Meteorol., 130, 207–222, 2005. Moore, C. J.: Frequency response corrections for eddy correlation systems, Bound. Lay. Meteorol., 37, 17–35, 1986. Prinn, R. and Weiss, R.: Advanced Global Atmospheric Gases Experiment Sponsored by NASA Upper Atmosphere Research Program. Trinidad Head, California 41° N, 124° W, 03 May 2005, http://agage.eas.gatech.edu/data.htm, 2005. Ridgwell, J. R., Marshall, S. J., and Gregson, K.: Consumption of atmospheric methane by soils: a process-based model, Global Biogeochem. Cycles, 13(1), 59–70, 1999. Schotanus, P., Nieuwstadt, F. T. M., and De~Bruin, H. A. R.: Temperature measurement with a sonic anemometer and its application to heat and moisture fluxes, Bound. Lay. Meteorol., 26, 81–93, 1983. Shimizu, T.: Practical applicability of high frequency correction theories to co₂ flux measured by a closed-path system, Bound. Lay. Meteorol., 122, 417–438, 2007. Simpson, I. J., Edwards, G. C., and Thurtell, G. W.: Variations in methane and nitrous oxide mixing ratios at the southern boundary of a canadian boreal forest, Atmos. Environ. 33, 1141–1150, 1999. Singh, J. S., Singh, S., Raghubanshi, A. S., Singh, S., Kashyap, A. K., and Reddy, V. S.: Effects of soil nitrogen, carbon and moisture on methane uptake by dry tropical forest soils, Plant and Soil, 196, 115–121, 1997. Sinha, V., Williams, J., Crutzen, P. J., and Lelieveld, J.: Methane emissions from boreal and tropical forest ecosystems derived from in-situ measurements, Atmos. Chem. Phys. Discuss., 7, 14011–14039, 2007. Spank, U. and Bernhofer, C.: Another simple method of spectral correction to obtain robust eddi-covariance results, Bound. Lay. Meteorol., 128, 403–422, 2008. Stull, R.: An introduction to boundary layer meteorology, D Reidel Publ. Comp., Dordrecht, The Netherlands, 670 pp., 1997. Verchot, L. V., Davidson, E. A., Henrique~Cattânio, J., and Ackerman, I. L.: Land-use change and biogeochemical controls of methane fluxes in soils of eastern amazonia, Ecosystems, 3, 41–56, 2000. Vigano, I., van Weelden, H., Holzinger, R., Keppler, F., McLeod, A., and Röckmann, T.: Effect of UV radiation and temperature on the emission of methane from plant biomass and structural components, Biogeosciences, 5, 937–947, 2008. Webb, E. K., Pearman, G. I., and Leuning, R.: Correction of the flux measurements for density effects due to heat and water vapour transfer, Q. J. Roy. Meteorol. Soc., 106, 85–100, 1980. Wienhold, F. G., Welling, M., and Harris, G. W.: Micrometeorological measurements and source region analysis of nitrous oxide fluxes from an agricultural soil, Atmos. Environ., 29(17), 2219–2227, 1995. Wieringa, J.: Representative roughness parameters for homogeneous terrain, Bound. Lay. Meteorol., 63, 323–363, 1993. Wille, C., Kutzbach, L., Sachs, T., Wagner, D., and Pfeiffer, E.: Methane emission from siberian arctic polygonal tundra: eddy covariance measurements and modeling, Global Change Biol., 14, 1395–1408, 2008.