Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 7 1 2007 10.5194/acpd-7-1995-2007 http://www.atmos-chem-phys-discuss.net/7/1995/2007/ http://www.atmos-chem-phys-discuss.net/7/1995/2007/acpd-7-1995-2007.html http://www.atmos-chem-phys-discuss.net/7/1995/2007/acpd-7-1995-2007.pdf 1995 2035 2007-02-08 Modelling the global tropospheric ozone budget: exploring the variability in current models O. Wild oliver.wild@atm.ch.cam.ac.uk Frontier Research Center for Global Change, JAMSTEC, Yokohama, Japan now at: Centre for Atmospheric Science, University of Cambridge, UK What are the largest uncertainties in modelling ozone in the troposphere, and how do they affect the calculated ozone budget? Published chemistry-transport model studies of tropospheric ozone differ significantly in their conclusions regarding the importance of the key processes controlling the ozone budget: influx from the stratosphere, chemical processing and surface deposition. This study surveys ozone budgets from previous studies and demonstrates that about two thirds of the increase in ozone production seen between early assessments and more recent model intercomparisons can be accounted for by increased precursor emissions. Model studies using recent estimates of emissions compare better with ozonesonde measurements than studies using older data, and the tropospheric burden of ozone is closer to that derived here from measurement climatologies, 335±10 Tg. However, differences between individual model studies remain large and cannot be explained by surface precursor emissions alone; cross-tropopause transport, wet and dry deposition, humidity, and lightning make large contributions to the differences seen between models. The importance of these processes is examined here using a chemistry-transport model to investigate the sensitivity of the calculated ozone budget to different assumptions about emissions, physical processes, meteorology and model resolution. The budget is particularly sensitive to the magnitude and location of lightning NO_x emissions, which remain poorly constrained; the 3–8 TgN/yr range in recent model studies may account for a 10% difference in tropospheric ozone burden and a 1.4 year difference in CH₄ lifetime. Differences in humidity and dry deposition account for some of the variability in ozone abundance and loss seen in previous studies, with smaller contributions from wet deposition and stratospheric influx. At coarse model resolutions stratospheric influx is systematically overestimated and dry deposition is underestimated; these differences are 5–8% at the 300–600 km grid-scales investigated here, similar in magnitude to the changes induced by interannual variability in meteorology. However, a large proportion of the variability between models remains unexplained, suggesting that differences in model chemistry and dynamics have a large impact on the calculated ozone budget, and these should be the target of future model intercomparisons. Berntsen, T., Isaksen, I S A., Wang, W.-C., and Liang, X.-Z.: Impacts of increased anthropogenic emissions in Asia on tropospheric ozone and climate. A global 3-D model study, Tellus, 48B, 13–32, 1996. Bethan, S., Vaughan, G., and Reid, S J.: A comparison of ozone and thermal tropopause heights and the impact of tropopause definition on quantifying the ozone content of the troposphere, Q. J. R. Meteorol. Soc., 122, 929–944, 1996. Bey, I., Jacob, D J., Yantosca, R M., et al.: Global modelling of tropospheric chemistry with assimilated meteorology: Model description and evaluation, J. Geophys. Res., 106(D19), 23 073–23 095, 2001. Chandra, S., Ziemke, J R., Min, W., and Read, W G.: Effects of 1997–1998 El Niño on tropospheric ozone and water vapor, Geophys. Res. Lett., 25, 3867–3870, 1998. Chatfield, R B. and Delany, A C.: Convection links biomass burning to increased tropical ozone: However, models will tend to overpredict \chemO_3, J. Geophys. Res., 95, 18 473–18 488, 1990. Crutzen, P J., Lawrence, M G., and Pöschl, U.: On the background photochemistry of tropospheric ozone, Tellus, 51A-B, 123–146, 1999. Dentener, F., Stevenson, D., Cofala, J., Mechler, R., Amann, M., Bergamaschi, P., Raes, F., and Derwent, R.: The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990–2030, Atmos. Chem. Phys., 5, 1731–1755, 2005. Dentener, F., Stevenson, D., Ellingsen, K., et al.: The global atmospheric environment for the next generation, Environ. Sci. Technol., 40, 3586–3594, doi:10.1021/es0523845, 2006a. Dentener, F., Drevet, J., Lamarque, J F., et~al.: Nitrogen and sulfur deposition on regional and global scales: A multi-model evaluation, Global Biogeochem. Cycles, 20, GB2020, doi:10.1029/2005GB002672, 2006b. Doherty, R M., Stevenson, D S., Collins, W J., and Sanderson, M G.: Influence of convective transport on tropospheric ozone and its precursors in a chemistry-climate model, Atmos. Chem. Phys., 5, 3205–3218, 2005. Fiore, A M., Horowitz, L W., Dlugokencky, E J., and West, J J.: Impact of meteorology and emissions on methane trends, 1990–2004, Geophys. Res. Lett., 33, L12809, doi:10.1029/2006GL026199, 2006. Fortuin, J P F. and Kelder, H.: An ozone climatology based on ozonesonde and satellite measurements, J. Geophys. Res., 103, 31 709–31 734, 1998. Gauss, M., Myhre, G., Pitari, G., et~al.: Radiative forcing in the 21st century due to ozone changes in the troposphere and lower stratosphere, J. Geophys. Res., 108, 4292, doi:10.1029/2002JD002624, 2003. Gettelman, A., Holton, J R., and Rosenlof, K H.: Mass fluxes of \chemO_3, \chemCH_4, \chemN_2O and \chemCF_2Cl_2 in the lower stratosphere calculated from observational data, J. Geophys. Res., 102, 19 149–19 159, 1997. Guenther, A., Hewitt, C N., Erickson, D., et~al.: A global model of natural volatile organic compound emissions, J. Geophys. Res., 100, 8873–8892, 1995. Hauglustaine, D A., Brasseur, G P., Walters, S., Rasch, P J., Müller, J.-F., Emmons, L K., and Carroll, M A.: MOZART, a global chemical transport model for ozone and related chemical tracers: 2. Model results and evaluation, J. Geophys. Res., 103, 28 291–28 335, 1998. Hauglustaine, D A., Hourdin, F., Jourdain, L., Filiberti, M.-A., Walters, S., Lamarque, J.-F., and Holland, E A.: Interactive chemistry in the Laboratoire de Météorologie Dynamique general circulation model: Description and background tropospheric chemistry evaluation, J. Geophys. Res., 109, D04314, doi:10.1029/2003JD003957, 2004. Holloway, T., Fiore, A M., and Galanter-Hastings, M.: Intercontinental transport of air pollution: Will emerging science lead to a new hemispheric treaty?, Environ. Sci. Technol., 37, 4535–4542, 2003. Holtslag, A A M. and Boville, B A.: Local versus nonlocal boundary layer diffusion in a global climate model, J. Clim., 6, 1825–1842, 1993. Horowitz, L W., Walters, S., Mauzerall, D L., et~al.: A global simulation of tropospheric ozone and related tracers: Description and evaluation of MOZART, version 2, J. Geophys. Res., 108(D24), 4784, doi:10.1029/2002JD002853, 2003. Hough, A M.: Development of a two-dimensional global tropospheric model: Model chemistry, J. Geophys. Res., 96, 7325–7362, 1991. Houweling, S., Dentener, F., and Lelieveld, J.: The impact of non-methane hydrocarbon compounds on tropospheric photochemistry, J. Geophys. Res., 103, 10 673–10 696, 1998. Isaksen, I S A., Hov, \O., Penkett, S A., and Semb, A.: Model analysis of the measured concentration of organic gases in the Norwegian Arctic, J. Atmos. Chem., 3, 3–27, 1985. Labrador, L J., von Kuhlmann, R., and Lawrence, M G.: The effects of lightning-produced NO_x and its vertical distribution on atmospheric chemistry: sensitivity simulations with MATCH-MPIC, Atmos. Chem. Phys., 5, 1815–1834, 2005. Lawrence, M G., Crutzen, P J., Rasch, P J., Eaton, B E., and Mahowald, N M.: A model for studies of tropospheric photochemistry: description, global distributions and evaluation, J. Geophys. Res., 104, 26 245–26 277, 1999. Lawrence, M G., von Kuhlmann, R., and Salzmann, M.: The balance of effects of deep convective mixing on tropospheric ozone, Geophys. Res. Lett., 30, 18, doi:10.1029/2003GL017644, 2003. Lelieveld, J. and Dentener, F J.: What controls tropospheric ozone? J. Geophys. Res., 105, 3531–3551, 2000. Lelieveld, J. and van Dorland, R.: Ozone chemistry changes in the troposphere and consequent radiative forcing of climate, in Atmospheric Ozone as a Climate Gas, W.C. Wang and I.S.A. Isaksen (eds.), NATO ASI Series I, Vol 32, Springer-Verlag, Berlin, 1995. Levy II, H., Kasibhatla, P S., Moxim, W J., Klonecki, A A., Hirsch, A I., Oltmans, S J., and Chameides, W L.: The global impact of human activity on tropospheric ozone, Geophys. Res. Lett., 24, 791–794, 1997. Li, D. and Shine, K P.: A 4-Dimensional Ozone Climatology for UGAMP Models, UGAMP Internal Report No. 35, April 1995. Logan, J A.: An analysis of ozonesonde data for the troposphere: Recommendations for testing 3-D models, and development of a gridded climatology for tropospheric ozone, J. Geophys. Res., 104, 16 115–16 149, 1999. Mallet, V. and Sportisse, B.: Uncertainty in a chemistry-transport model due to physical parameterizations and numerical approximations: An ensemble approach applied to ozone modeling, J. Geophys. Res., 111, D01302, doi:10.1029/2005JD006149, 2006. McLinden, C A., Olsen, S., Hannegan, B., Wild, O., Prather, M J., and Sundet, J.: Stratospheric ozone in 3-D models: A simple chemistry and the cross-tropopause flux, J. Geophys. Res., 105, 14 653–14 665, 2000. Mickley, L J., Murti, P P., Jacob, D J., Logan, J A., Rind, D., and Koch, D.: Radiative forcing from tropospheric ozone calculated with a unified chemistry-climate model, J. Geophys. Res., 104, 30 153–30 172, 1999. Müller, J.-F. and Brasseur, G.: IMAGES: A three-dimensional chemical transport model of the global troposphere, J. Geophys. Res., 100(D8), 16 445–16 490, 1995. Murphy, D M. and Fahey, D W.: An estimate of the flux of stratospheric reactive nitrogen and ozone into the troposphere, J. Geophys. Res., 99, 5325–5332, 1994. Olivier, J G J. and Berdowski, J J M.: Global emissions sources and sinks, in The Climate System, edited by J J M. Berdowski, R. Guicherit and B J. Heij, pp 33–78, A A. Balkemer Publishers, Lisse, The Netherlands. Olivier, J G J., Bouwman, A F., van der Maas, C W M., et~al.: Description of EDGAR Version 2.0, RIVM/TNO report 771060~002, RIVM, Bilthoven, December 1996. Olsen, S C., McLinden, C A., and Prather, M J.: The stratospheric \chemN_2O–NO_y system: Testing uncertainties in a 3-D framework, J. Geophys. Res., 106, 28 771–28 784, 2001. Park, R J., Pickering, K E., Allen, D J., Stenchikov, G L., and Fox-Rabinovitz, M S.: Global simulation of tropospheric ozone using the University of Maryland Chemical Transport Model (UMD-CTM): 1. Model description and evaluation, J. Geophys. Res., 109, D09301, doi:10.1029/2003JD004266, 2004. Pickering, K E., Wang, Y., Tao, W.-K., Price, C., and Müller, J.-F.: Vertical distributions of lightning NO_x for use in regional and global chemical transport models, J. Geophys. Res., 103(D23), 31 203–31 216, doi:10.1029/98JD02651, 1998. Pöschl, U., von Kuhlmann, R., Poisson, N., and Crutzen, P J.: Development and intercomparison of condensed isoprene oxidation mechanisms for global atmospheric modeling, J. Atmos. Chem., 37, 29–52, 2000. Prather, M J. and Ehhalt, D.: Atmospheric Chemistry and Greenhouse Gases, in Climate Change 2001: The Scientific Basis, Cambridge University Press, Cambridge, UK, 2001. Price, C. and Rind, D.: A simple lightning parameterization for calculating global lightning distributions, J. Geophys. Res., 97, 9919–9933, 1992. Price, C., Penner, J., and Prather, M J.: NO_x from lightning: 1. Global distribution based on lightning physics, J. Geophys. Res., 102, 5929–5941, 1997. Roelofs, G.-J. and Lelieveld, J.: Distribution and budget of \chemO_3 in the troposphere calculated with a chemistry general circulation model, J. Geophys. Res., 100(D10), 20 983–20 998, 1995. Roelofs, G.-J. and Lelieveld, J.: Model study of cross-tropopause \chemO_3 transports on tropospheric \chemO_3 levels, Tellus, 49B, 38–55, 1997. Roelofs, G.-J. and Lelieveld, J.: Tropospheric ozone simulation with a chemistry-general circulation model: Influence of higher hydrocarbon chemistry, J. Geophys. Res., 105(D18), 22 697–22 712, 2000. Rotman, D A., Atherton, C S., Bergmann, D J., et~al.: IMPACT, the LLNL 3-D global atmospheric chemical transport model for the combined troposphere and stratosphere: Model description and analysis of ozone and other trace gases, J. Geophys. Res., 109, D04303, doi:10.1029/2002JD003155, 2004. Shindell, D T., Grenfell, J L., Rind, D., and Grewe, V.: Chemistry-climate interactions in the Goddard Institute for Space Studies general circulation model. 1. Tropospheric chemistry model description and evaluation, J. Geophys. Res., 106(D8), 8047–8075, 2001. Shindell, D T., Faluvegi, G., and Bell, N.: Preindustrial to present day radiative forcing by tropospheric ozone from improved simulations with the GISS chemistry-climate GCM, Atmos. Chem. Phys., 3, 1675–1702, 2003. Shindell, D T., Faluvegi, G., Stevenson, D S., et~al.: Multi-model simulations of carbon monoxide: Comparison with observations and projected near-future changes, J. Geophys. Res., 111, D19306, doi:10.1029/2006JD007100, 2006. Stevenson, D S., Johnson, C E., Collins, W J., Derwent, R G., and Edwards, J M.: Future tropospheric ozone radiative forcing and methane turnover – the impact of climate change, Geophys. Res. Lett., 27, 2073–2076, 2000. Stevenson, D S., Doherty, R M., Sanderson, M G., Collins, W J., Johnson, C E., and Derwent, R G.: Radiative forcing from aircraft NO_x emissions: Mechanisms and seasonal dependence, J. Geophys. Res., 109, D17307, doi:10.1029/2004JD004759, 2004. Stevenson, D., Dentener, F J., Schultz, M G., et~al.: Multi-model ensemble simulations of present-day and near-future tropospheric ozone, J. Geophys. Res., 111, D08301, doi:10.1029/2005JD006338, 2006. Sudo, K. and Takahashi, M.: Simulation of tropospheric ozone changes during 1997–1998 El Niño: Meteorological impact on tropospheric photochemistry, Geophys. Res. Lett., 28, 4091–4094, 2001. Sudo, K., Takahashi, M., and Akimoto, H.: CHASER: A global chemical model of the troposphere 2. Model results and evaluation, J. Geophys. Res., 107, doi:10.1029/2001JD001114, 2002. Tie, X., Madronich, S., Walters, S., Zhang, R., Rasch, P., and Collins, W.: Effect of clouds on photolysis and oxidants in the troposphere, J. Geophys. Res., 108(D20), 4642, doi:10.1029/2003JD003659, 2003. Thompson, A M., Witte, J C., McPeters, R D., et~al.: Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2000 tropical ozone climatology 1. Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground-based measurements, J. Geophys. Res., 108(D2), 8238, doi:10.1029/2001JD000967, 2003. von Kuhlmann, R., Lawrence, M G., Crutzen, P J., and Rasch, P J.: A model for studies of tropospheric ozone and nonmethane hydrocarbons: Model description and ozone results, J. Geophys. Res., 108(D9), 4294, doi:10.1029/2002JD002893, 2003. von Kuhlmann, R., Lawrence, M G., Pöschl, U., and Crutzen, P J.: Sensitivities in global scale modeling of isoprene, Atmos. Chem. Phys., 4, 1–17, 2004. Wang, Y., Logan, J A., and Jacob, D J.: Global simulation of tropospheric \chemO_3–NO_x–hydrocarbon chemistry. 2. Model evaluation and global ozone budget, J. Geophys. Res., 103, 10 727–10 755, 1998. Wauben, W M F., Fortuin, J P F., van Velthoven, P F J., and Kelder, H.: Comparison of modelled ozone distributions with sonde and satellite observations, J. Geophys. Res., 103, 3511–3530, 1998. Wesely, M L.: Parameterization of surface resistances to gaseous dry deposition in regional-scale numerical models, Atmos. Environ., 23, 1293–1304. 1989. Wild, O. and Prather, M J.: Excitation of the primary tropospheric chemical mode in a global 3-D model, J. Geophys. Res., 105, 24 647–24 660, 2000. Wild, O. and Prather, M J.: Global tropospheric ozone modelling: Quantifying errors due to grid resolution, J. Geophys. Res., 111, D11305, doi:10.1029/2005JD006605, 2006. Wild, O., Zhu, X., and Prather, M J.: Fast-J: Accurate simulation of in- and below-cloud photolysis in tropospheric chemical models, J. Atmos. Chem., 37, 245–282, 2000. Wild, O., Pochanart, P., and Akimoto, H.: Trans-Eurasian transport of ozone and its precursors, J. Geophys. Res., 109, D11302, doi:10.1029/2003JD004501, 2004. Wong, S., Wang, W.-C., Isaksen, I S A., Berntsen, T K., and Sundet, J K.: A global climate-chemistry model study of present-day tropospheric chemistry and radiative forcing from changes in tropospheric \chemO_3 since the preindustrial period, J. Geophys. Res., 109, D11309, doi:10.1029/2003JD003998, 2004. Wu, S., Mickley, L J., Jacob, D J., Logan, J A., Yantosca, R M., and Rind, D.: Why are there large differences between models in global budgets of tropospheric ozone?, J. Geophys. Res., in press, 2007. Zeng, G. and Pyle, J A.: Influence of El Niño Southern Oscillation on stratosphere/troposphere exchange and the global tropospheric ozone budget, Geophys. Res. Lett., 32, L01814, doi:10.1029/2004GL021353, 2005.