Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 7 17 2007 10.5194/acp-7-4537-2007 http://www.atmos-chem-phys.net/7/4537/2007/ http://www.atmos-chem-phys.net/7/4537/2007/acp-7-4537-2007.html http://www.atmos-chem-phys.net/7/4537/2007/acp-7-4537-2007.pdf 4537 4552 2007-09-03 A new formulation of equivalent effective stratospheric chlorine (EESC) P. A. Newman paul.a.newman@nasa.gov J. S. Daniel D. W. Waugh E. R. Nash Atmospheric Chemistry and Dynamics Branch, NASA Goddard Space Flight Center, Greenbelt, MD, USA NOAA Earth System Research Laboratory/Chemical Sciences Division, Boulder, CO, USA Johns Hopkins University, Baltimore, MD, USA Science Systems and Applications, Inc., Lanham, MD, USA Equivalent effective stratospheric chlorine (EESC) is a convenient parameter to quantify the effects of halogens (chlorine and bromine) on ozone depletion in the stratosphere. We show, discuss, and analyze a new formulation of EESC that now includes the effects of age-of-air dependent fractional release values and an age-of-air spectrum. This EESC can be more appropriately applied to various parts of the stratosphere because of this dependence on mean age-of-air. This new formulation provides quantitative estimates of EESC that can be directly related to inorganic chlorine and bromine throughout the stratosphere. In this paper, we first provide a detailed description of the EESC calculation. We then use this EESC formulation to estimate that human-produced ozone depleting substances will recover to 1980 levels in 2041 in the midlatitudes, and 2067 over Antarctica. These recovery dates are based upon the assumption that the international agreements for regulating ozone-depleting substances are adhered to. In addition to recovery dates, we also estimate the uncertainties and possible problems in the estimated times of recovery. The midlatitude recovery of 2041 has a 95% confidence uncertainty from 2028 to 2049, while the 2067 Antarctic recovery has a 95% confidence uncertainty from 2056 to 2078. The principal uncertainties are from the estimated mean age-of-air and fractional release values, and the assumption that these quantities are time independent. Using other model estimates of age decrease due to climate change, we estimate that midlatitude recovery may be significantly accelerated. Anderson, J., Russell III, J M., Solomon, S., and Deaver, L E.: Halogen Occultation Experiment confirmation of stratospheric chlorine decreases in accordance with the Montreal Protocol, J. Geophys. Res., 103(D4), 4483–4490, doi:10.1029/1999JD901075, 2000. Andrews, A E., Boering, K A., Daube, B C., Wofsy, S C., Loewenstein, M., Jost, H., Podolske, J R., Webster, C R., Herman, R L., Scott, D C., Flesch, G J., Moyer, E J., Elkins, J W., Dutton, G S., Hurst, D F., Moore, F L., Ray, E A., Romashkin, P A., and Strahan, S E.: Mean ages of stratospheric air derived from in situ observations of \chemCO_2, \chemCH_4, and \chemN_2O, J. Geophys. Res., 106(D23), 32 295–32 314, doi:10.1029/2001JD000465, 2001. Austin, J. and Li, F.: On the relationship between the strength of the Brewer-Dobson circulation and the age of stratospheric air, Geophys. Res. Lett., 33, L17807, doi:10.1029/2006GL026867, 2006. Bodeker, G E., Waugh, D W., Akiyoshi,, H., Braesicke, P., Eyring, V., Fahey, D W., Manzini, E., Newchurch, M J., Portmann, R W., Robock, A., Shine, K P., Steinbrecht, W., and Weatherhead. E C.: The ozone layer in the 21$^\mathrmst$ Century, Chapter 6 in World Meteorological Organization: Scientific assessment of ozone depletion: 2006, Global Ozone Research and Monitoring Project – Report No. 50, Geneva, 43~pp., 2007. Chipperfield, M P., Randel, W J., Bodeker, G E., Dameris, M., Fioletov, V E., Friedl, R R., Harris, N R P., Logan. J A., McPeters, R D., Muthama, N J., Peter, T., Shepherd, T G., Shine, K~.P., Solomon, S., Thomason, L W., and Zawodny, J M.: Global ozone: Past and future, Chapter 4 in World Meteorological Organization: Scientific assessment of ozone depletion: 2002, Global Ozone Research and Monitoring Project – Report No. 47, Geneva, 91~pp., 2003. Clerbaux, C., Cunnold, D M., Anderson, J., Engel, A., Fraser, P J., Mahieu, E., Manning, A., Miller, J., Montzka, S A., Nassar, R., Prinn, R., Reimann, S., Rinsland, C P., Simmonds, P., Verdonik, D., Weiss, R., Wuebbles, D., and Yokouchi, Y.: Long-lived Compounds, Chapter 1 in World Meteorological Organization: Scientific assessment of ozone depletion: 2006, Global Ozone Research and Monitoring Project – Report No. 50, Geneva, 63~pp., 2007. Daniel, J S., Solomon, S., and Albritton, D L.: On the evaluation of halocarbon radiative forcing and global warming potentials, J. Geophys. Res., 100(D1), 1271–1285, doi:10.1029/94JD02516, 1995. Daniel, J S., Solomon, S., Portmann, R W., and Garcia, R R.: Stratospheric ozone destruction: The importance of bromine relative to chlorine, J. Geophys. Res., 104(D19), 23 871–23 880, doi:10.1029/1999JD900381, 1999. Daniel, J S., Velders, G J M., Douglass, A R., Forster, P M D., Hauglustaine, D A., Isaksen, I S A., Kuijpers, L J M., McCulloch, A., and Wallington, T J.: Halocarbon scenarios, ozone depletion potentials, and global warming potentials, Chapter 8 in World Meteorological Organization: Scientific assessment of ozone depletion: 2006, Global Ozone Research and Monitoring Project – Report No. 50, Geneva, 39~pp., 2007. Danilin, M Y., Sze, N.-D., Ko, M K., Rodriguez, J M., and Prather, M J.: Bromine-chlorine coupling in the Antarctic ozone hole, Geophys. Res. Lett., 23(2), 153–156, doi:10.1029/95GL03783, 1996. Dhomse, S., Weber, M., Wohltmann, I., Rex, M., and Burrows, J P.: On the possible causes of recent increases in northern hemispheric total ozone from a statistical analysis of satellite data from 1979 to 2003, Atmos. Chem. Phys., 6, 1165–1180, 2006. Dorf, M., Bösch, H. Butz, A., Camy-Peyret, C., Chipperfield, M P., Engel, A., Goutail, F., Grunow, K., Hendrick, F., Hrechanyy, S., Naujokat, B., Pommereau, J.-P., Van Roozendael, M., Sioris, C., Stroh, F., Weidner, F., and Pfeilsticker, K.: Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles, Atmos. Chem. Phys., 6, 2483–2501, 2006. Farman, J C., Gardiner, B G., and Shanklin, J D.: Large losses of total ozone in Antarctica reveal seasonal \chemClO_x/NO_x interaction, Nature, 315, 207–210, doi:10.1038/315207a0, 1985. Fioletov, V E., Bodeker, G E., Miller, A J., McPeters, R D., and Stolarski, R.: Global and zonal total ozone variations estimated from ground-based and satellite measurements, J. Geophys. Res., 107(D22), 4647, doi:10.1029/2001JD001350, 2002. Fleming, E L., Jackman, C H., Stolarski, R S., and Considine, D B.: Simulation of stratospheric tracers using an improved empirically based two-dimensional model transport formulation, J. Geophys. Res., 104(D1), 1759–1766, doi:10.1029/1998JD10028, 1999. Guillas, S., Tiao, G C., Wuebbles, D J., and Zubrow, A.: Statistical diagnostic and correction of a chemistry-transport model for the prediction of total column ozone, Atmos. Chem. Phys., 6, 525–537, 2006. % Law, K S., Sturges, W T., Blake, D R., Blake, N J., Burkholder, J B., Butler, J H., Cox, R A., Haynes, P H., Ko, M K W., Kreher, K., Mari, C., Pfeilsticker, K., Plane, J .M C., Salawitch, R J., Schiller, C., Sinnhuber, B.-M., von Glasow, R., Warwick, N J., Wuebbles, D J., and Yvon-Lewis, S A.: Halogenated very short-lived substances, Chapter 2 in World Meteorological Organization: Scientific assessment of ozone depletion: 2006, Global Ozone Research and Monitoring Project – Report No. 50, Geneva, 57~pp., 2007. Madronich, S., Velders, G J M., Daniel, J S., Lal, M., McCulloch, A., and Slaper, H.: Halocarbon scenarios for the future ozone layer and related consequences, Chapter 11 in World Meteorological Organization: Scientific assessment of ozone depletion: 1998, Global Ozone Research and Monitoring Project – Report No. 44, Geneva, 38~pp., 1999. Montzka, S A., Butler, J H., Myers, R C., Thompson, T M., Swanson, T H., Clarke, A D., Lock, L T., and Elkins, J W.: Decline in the tropospheric abundance of halogen from halocarbons: Implications for stratospheric ozone depletion, Science, 272, 1318–1322, doi:10.1126/science.272.5266.1318, 1996. Montzka, S A., Fraser, P J., Butler, J H., Connell, P S., Cunnold, D M., Daniel, J S., Derwent, R G., Lal, S., McCulloch, A., Oram, D E., Reeves, C E., Sanhueza, E., Steele, L P., Velders, G J M., Weiss, R F., and Zander, R J.: Controlled substances and other source gases, Chapter 1 in World Meteorological Organization: Scientific assessment of ozone depletion: 2002, Global Ozone Research and Monitoring Project – Report No. 47, Geneva, 83~pp., 2003. Newchurch, M J., Yang, E.-S., Cunnold, D M., Reinsel, G C., Zawodny, J M., , and Russel III, J. M.: Evidence for slowdown in stratospheric ozone loss: First stage of ozone recovery, J. Geophys. Res., 108(D16), 4507, doi:10.1029/2003JD003471, 2003. Newman, P A., Pyle, J A., Austin, J., Braathen, G O., Canziani, P O., Carslaw, K S., Forster, P M de~F., Godin-Beekman, S., Knudsen, B M., Kreher, K., Nakane, H., Pawson, S., Ramaswamy, V., Rex, M., Salawitch, R J., Shindell, D T., Tabazadeh, A., and Toohey, D W.: Polar stratospheric ozone: Past and future, Chapter 3 in World Meteorological Organization: Scientific assessment of ozone depletion: 2002, Global Ozone Research and Monitoring Project – Report No. 47, Geneva, 104~pp., 2003. Newman, P A., Nash, E R., Kawa, S R., Montzka, S A., and Schauffler, S M.: When will the Antarctic ozone hole recover?, Geophys. Res. Lett., 33, L12814, doi:10.1029/2005GL025232, 2006. Prinn, R G., Zander, R, Cunnold, D M., Elkins, J W., Engel, A., Fraser, P J., Gunson, M R., Ko, M K W., Mahieu, E., Midgley, P M., Russell III, J M., Volk, C M., and Weiss, R F.: Long-lived ozone-related compounds, Chapter 1 in World Meteorological Organization: Scientific assessment of ozone depletion: 1998, Global Ozone Research and Monitoring Project – Report No. 44, Geneva, 54~pp., 1999. Sarma, K M. and Bankobeza, G M. (Eds.): The Montreal protocol on substances that deplete the ozone layer, United Nations Environment Programme, Nairobi, Kenya, 2000. Schauffler, S M., Atlas, E L., Donnelly, S G., Andrews, A., Montzka, S A., Elkins, J W., Hurst, D F., Romashkin, P A., Dutton, G S., and Stroud, V.: Chlorine budget and partitioning during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE), J. Geophys. Res., 108(D5), 4173, doi:10.1029/2001JD002040, 2003. Schoeberl, M R., Douglass, A R., Polansky, B., Boone, C., Walker, K A., and Bernath, P.: Estimation of stratospheric age spectrum from chemical tracers, J. Geophys. Res., 110, D21303, doi:10.1029/2005JD006125, 2005. Sinnhuber, B.-M., Sheode, N., Sinnhuber, M., Chipperfield, M P., and Feng, W.: The contribution of anthropogenic bromine emissions to past stratospheric ozone trends: a modelling study, Atmos. Chem. Phys. Discuss., 6, 6497–6524, 2006. Solomon, S. and Albritton, D.: Time-dependent ozone depletion potentials for short- and long-term forecasts, Nature, 357, 33–37, doi:10.1038/357033a0, 1992. Solomon, S., Wuebbles, D., Isaksen, I., Kiehl, J. Lal, M., Simon, P., and Sze, N.-D.: Ozone depletion potentials, global warming potentials, and future chlorine/bromine loading, Chapter 13 in World Meteorological Organization: Scientific assessment of ozone depletion: 1994, Global Ozone Research and Monitoring Project – Report No. 37, Geneva, 36~pp., 1995. Stolarski, R S., Douglass, A R., Steenrod, S., and Pawson, S.: Trends in stratospheric ozone: Lessons learned from a 3D chemical transport model, J. Atmos. Sci., 63, 1028–1041, doi:10.1175/JAS3650.1, 2006a. Stolarski, R S., Douglass, A R., Gupta, M., Newman, P A., Pawson, S., Schoeberl, M R., and Nielsen, J E.: An ozone increase in the Antarctic summer stratosphere: A dynamical response to the ozone hole, Geophys. Res. Lett., 33, L21805, doi:10.1029/2006GL026820, 2006b. 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.: Evaluation of source gas lifetimes from Stratospheric observations, J. Geophys. Res., 102(D21), 25 543–25 564, doi:10.1029/97JD02215, 1997. Waugh, D W. and Hall, T M.: Age of stratospheric air: Theory, observations, and models, Rev. Geophys., 40(4), 1010, doi:10.1029/2000RG000101, 2002. World Meteorological Organization: Scientific assessment of ozone depletion: 1994, Global Ozone Research and Monitoring Project – Report No. 37, Geneva, 1995. World Meteorological Organization: Scientific assessment of ozone depletion: 1998, Global Ozone Research and Monitoring Project – Report No. 44, Geneva, 1999. World Meteorological Organization: Scientific assessment of ozone depletion: 2002, Global Ozone Research and Monitoring Project – Report No. 47, Geneva, 2003. World Meteorological Organization: Scientific assessment of ozone depletion: 2006, Global Ozone Research and Monitoring Project – Report No. 50, Geneva, 2007. Yang, E.-S., Cunnold, D M., Newchurch, M J., and Salawitch, R J.: Change in ozone trends at southern high latitudes, Geophys. Res. Lett., 32, L12812, doi:10.1029/2004GL022296, 2005.