Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 7 6 2007 10.5194/acpd-7-15781-2007 http://www.atmos-chem-phys-discuss.net/7/15781/2007/ http://www.atmos-chem-phys-discuss.net/7/15781/2007/acpd-7-15781-2007.html http://www.atmos-chem-phys-discuss.net/7/15781/2007/acpd-7-15781-2007.pdf 15781 15803 2007-11-12 Method for evaluating trends in greenhouse gases from ground-based remote FTIR measurements over Europe T. Gardiner tom.gardiner@npl.co.uk A. Forbes P. Woods M. deMaziere C. Vigouroux E. Mahieu P. Demoulin V. Velazco J. Notholt T. Blumenstock F. Hase I. Kramer R. Sussman W. Stremme J. Mellqvist A. Strandberg K. Ellingsen M. Gauss National Physical Laboratory, Teddington, UK Belgisch Instituut voor Ruimte-Aëronomie, Brussels, Belgium University of Liège, Institute of Astrophysics and Geophysics, Liège, Belgium University of Bremen, Dept. of Physics, Institute of Environmental Physics, Bremen, Germany Forschungszentrum Karlsruhe, Institute of Meteorology and Climate Research, Atmospheric Trace Constituents and Remote Sensing, Karlsruhe, Germany Forschungszentrum Karlsruhe, Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe, Germany Chalmers University of Technology, Goteburg, Sweden University of Oslo, Oslo, Norway This paper describes the statistical analysis of annual trends in long term datasets of greenhouse gas measurements taken over ten or more years. The analysis technique employs a bootstrap resampling method to determine both the long-term and intra-annual variability of the datasets, together with the uncertainties on the trend values. The method has been applied to data from a European network of ground-based solar FTIR instruments to determine the trends in the tropospheric, stratospheric and total columns of ozone, nitrous oxide, carbon monoxide, methane, ethane and HCFC-22. The suitability of the method has been demonstrated through statistical validation of the technique, and comparison with ground-based in-situ measurements and 3-D atmospheric models. Berthouex, P. M. and Brown, L. C.: Statistics for Environmental Engineers, CRC Press, Inc., US, 1994. Cox, M. G, Harris, P. M., Milton, M. J. T., and Woods, P. T.: Method for Evaluating Trends in Ozone Concentration Data and its Application to Data from the UK Ruural Ozone Monitoring Network, NPL Report CMSC 15/02, November, 2002. DeMazière, M., Vigouroux, C., Gardiner, T., Coleman, M., Woods, P., Ellingsen, K., Gauss, M., Isaken, I., Blumenstock, T., Hase, F., Kramer, I., Camy-Peyret, C., Chelin, P., Mahieu, E., Demoulin, P., Duchatelet, P., Mellqvist, J., Strandberg, A., Velazco, V., Notholt, J., Sussman, R., Stremme, W., and Rockmann, A.: The exploitation of ground-based Fourier transform infrared observations for the evaluation of tropospheric trends of greenhouse gases over Europe, Environmental Sciences, 2(2–3), 283–293, 2005. Efron, B.: The Jackknife, the Bootstrap, and Other Resampling Plans, Society for Industrial and Applied Mathematics, Philadelphia, 1982. Efron, B. and Tibshirani, R.: An Introduction to the Bootstrap, Monographs on Statistics and Applied Probability 57, Chapman and Hall, 1993. Gatz, D. F. and Smith, L.: The standard error of a weighted mean concentration – II, Estimating confidence intervals, Atmos. Environ., 29(11), 1195–1200, 1995. Gauss, M., Isaksen, I. S. A., Lee, D. S., and Søvde, O. A.: Impact of aircraft NO_x emissions on the atmosphere – tradeoffs to reduce the impact, Atmos. Chem. Phys., 6, 1529–1548, 2006. Isaksen, I. S. A., Zerefos, C. S., Kourtidis, K., Meleti, C., Dalsoren, S. B., Sundet, J. K., Grini, A., Zanis, P., and Balis, D.: Tropospheric ozone changes at unpolluted and semipolluted regions induced by stratospheric ozone changes, J. Geophys. Res., 110(2), doi:10.1029/2004JD004618, 2005. Lawson, C. L. and Hanson, R. J.: Solving Least Squares Problems, Prentice Hall, Englewood Cliffs, New Jersey, 1974. Olivier, J., Bouwman, A., Berdowski, J., Bloos, J., Visschedijk, A., van der Mass, C., and Zandveld, P.: Sectoral emission inventories of greenhouse gases for 1990 on a per country basis as well as on 1×1 degrees, Environ. Sci. Policy, 2, 241–263, 1999. Oltmans, S. J., Lefohn, A. S., Scheel, H. E., Harris, J. M., et al.: Trends in ozone in the troposphere, Geophys. Res. Lett., 25(2), 139–142, 1998. WMO: Scientific Assessment of Ozone Depletion: 2002, Global Ozone Research and Monitoring Project – Report No. 47, 498 pp, Geneva, 2003.