ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-7533-2011 Projections of UV radiation changes in the 21st century: impact of ozone recovery and cloud effects Bais A. F. 1 Tourpali K. 1 Kazantzidis A. 2 Akiyoshi H. 3 Bekki S. 4 Braesicke P. 5 Chipperfield M. P. 6 Dameris M. 7 Eyring V. 7 Garny H. 7 Iachetti D. 8 Jöckel P. 7 Kubin A. 9 Langematz U. 9 Mancini E. 8 Michou M. 10 Morgenstern O. 11 Nakamura T. 3 Newman P. A. 12 Pitari G. 8 Plummer D. A. 13 Rozanov E. 14 15 Shepherd T. G. 16 Shibata K. 17 Tian W. 6 Yamashita Y. 3 Aristotle University of Thessaloniki, Department of Physics, Thessaloniki, Greece University of Patras, Department of Physics, Patras, Greece National Institute for Environmental Studies, Tsukuba, Japan Service d'Aeronomie, Institut Pierre-Simone Laplace, Paris, France University of Cambridge, Department of Chemistry, Cambridge, UK Institute for Climate and Atmospheric Science, University of Leeds, Leeds, UK Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany Università L'Aquila, Dipartimento di Fisica, L'Aquila, Italy Freie Universität Berlin, Institut für Meteorologie, Berlin, Germany GAME/CNRM (Météo-France, CNRS), Toulouse, France National Institute of Water and Atmospheric Research, Lauder, New Zealand NASA Goddard Space Flight Center, Greenbelt, MD, USA Environment Canada, Victoria, BC, Canada Physical-Meteorological Observatory Davos/World Rad. Center, Davos, Switzerland Institute for Atmospheric and Climate Science ETH, Zurich, Switzerland Department of Physics, University of Toronto, Toronto, Canada Meteorological Research Institute, Tsukuba, Japan 01 08 2011 11 15 7533 7545 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/11/7533/2011/acp-11-7533-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/7533/2011/acp-11-7533-2011.pdf

Monthly averaged surface erythemal solar irradiance (UV-Ery) for local noon from 1960 to 2100 has been derived using radiative transfer calculations and projections of ozone, temperature and cloud change from 14 chemistry climate models (CCM), as part of the CCMVal-2 activity of SPARC. Our calculations show the influence of ozone depletion and recovery on erythemal irradiance. In addition, we investigate UV-Ery changes caused by climate change due to increasing greenhouse gas concentrations. The latter include effects of both stratospheric ozone and cloud changes. The derived estimates provide a global picture of the likely changes in erythemal irradiance during the 21st century. Uncertainties arise from the assumed scenarios, different parameterizations – particularly of cloud effects on UV-Ery – and the spread in the CCM projections. The calculations suggest that relative to 1980, annually mean UV-Ery in the 2090s will be on average ~12 % lower at high latitudes in both hemispheres, ~3 % lower at mid latitudes, and marginally higher (~1 %) in the tropics. The largest reduction (~16 %) is projected for Antarctica in October. Cloud effects are responsible for 2–3 % of the reduction in UV-Ery at high latitudes, but they slightly moderate it at mid-latitudes (~1 %). The year of return of erythemal irradiance to values of certain milestones (1965 and 1980) depends largely on the return of column ozone to the corresponding levels and is associated with large uncertainties mainly due to the spread of the model projections. The inclusion of cloud effects in the calculations has only a small effect of the return years. At mid and high latitudes, changes in clouds and stratospheric ozone transport by global circulation changes due to greenhouse gases will sustain the erythemal irradiance at levels below those in 1965, despite the removal of ozone depleting substances. At northern high latitudes (60°–90°), the projected decreases in cloud transmittance towards the end of the 21st century will reduce the yearly average surface erythemal irradiance by ~5 % with respect to the 1960s.

 References Akiyoshi, H., Zhou, L. B., Yamashita, Y., Sakamoto, K., Yoshiki, M., Nagashima, T., Takahashi, M., Kurokawa, J., Takigawa, M., and Imamura, T.: A CCM simulation of the breakup of the Antarctic polar vortex in the years 1980–2004 under the CCMVal scenarios, J. Geophys. Res.-Atmos., 114, D03103, http://dx.doi.org/10.1029/2007JD009261doi:10.1029/2007JD009261, 2009. Akiyoshi, H., Yamashita, Y., Sakamoto, K., Zhou, L. B., and Imamura, T.: Recovery of stratospheric ozone in calculations by the Center for Climate System Research/National Institute for Environmental Studies chemistry-climate model under the CCMVal-REF2 scenario and a no-climate-change run, J. Geophys. Res., 115, D19301, doi:19310.11029/12009jd012683, 2010. Arola, A., Lakkala, K., Bais, A., Kaurola, J., Meleti, C., and Taalas, P.: Factors affecting short- and long-term changes of spectral UV irradiance at two European stations, J. Geophys. Res.-Atmos., 108, 4549, http://dx.doi.org/10.1029/2003JD003447doi:10.1029/2003JD003447, 2003. Austin, J. and Wilson, R. J.: Sensitivity of polar ozone to sea surface temperatures and halogen amounts, J. Geophys. Res.-Atmos., 115, D18303, http://dx.doi.org/10.1029/2009JD013292doi:10.1029/2009JD013292, 2010. Austin, J., Scinocca, J., Plummer, D., Oman, L., Waugh, D., Akiyoshi, H., Bekki, S., Braesicke, P., Butchart, N., Chipperfield, M., Cugnet, D., Dameris, M., Dhomse, S., Eyring, V., Frith, S., Garcia, R. R., Garny, H., Gettelman, A., Hardiman, S. C., Kinnison, D., Lamarque, J. F., Mancini, E., Marchand, M., Michou, M., Morgenstern, O., Nakamura, T., Pawson, S., Pitari, G., Pyle, J., Rozanov, E., Shepherd, T. G., Shibata, K., Teyssedre, H., Wilson, R. J., and Yamashita, Y.: Decline and recovery of total column ozone using a multimodel time series analysis, J. Geophys. Res.-Atmos., 115, D00M10, http://dx.doi.org/10.1029/2010JD013857doi:10.1029/2010JD013857, 2010. Bais, A. F., Lubin, D., Arola, A., Bernhard, G., Blumthaler, M., Chubarova, N., Erlick, C., Gies, H. P., Krotkov, N., Lantz, K., Mayer, B., McKenzie, R. L., Piacentini, R., Seckmeyer, G., Slusser, J. R., and Zerefos, C.: Surface ultraviolet radiation: Past, present and future, Geneva, Switzerland, Chapter 7 in Scientific Assessment of Ozone Depletion: 2006, Global Ozone Research and Monitoring Project–Report No 47, World Meteorological Organization, 58, 2007. Bernhard, G., Booth, C. R., Ehramjian, J. C., Stone, R., and Dutton, E. G.: Ultraviolet and visible radiation at Barrow, Alaska: Climatology and influencing factors on the basis of version 2 National Science Foundation network data, J. Geophys. Res.-Atmos., 112, D09101, doi:09110.01029/02006JD007865, 2007. Blumthaler, M., Ambach, W., and Salzgeber, M.: Effects of cloudiness on global and diffuse UV irradiance in a high-mountain area, Theor. Appl. Climatol., 50, 23–30, 1994. Butchart, N., Scaife, A. A., Bourqui, M., de Grandpre, J., Hare, S. H. E., Kettleborough, J., Langematz, U., Manzini, E., Sassi, F., Shibata, K., Shindell, D., and Sigmond, M.: Simulations of anthropogenic change in the strength of the Brewer-Dobson circulation, Clim. Dynam., 27, 727–741, http://dx.doi.org/10.1007/s00382-006-0162-4doi:10.1007/s00382-006-0162-4, 2006. Butchart, N., Cionni, I., Eyring, V., Shepherd, T. G., Waugh, D. W., Akiyoshi, H., Austin, J., Bruhl, C., Chipperfield, M. P., Cordero, E., Dameris, M., Deckert, R., Dhomse, S., Frith, S. M., Garcia, R. R., Gettelman, A., Giorgetta, M. A., Kinnison, D. E., Li, F., Mancini, E., McLandress, C., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Sassi, F., Scinocca, J. F., Shibata, K., Steil, B., and Tian, W.: Chemistry-Climate Model Simulations of Twenty-First Century Stratospheric Climate and Circulation Changes, J. Climate, 23, 5349–5374, http://dx.doi.org/10.1175/2010jcli3404.1doi:10.1175/2010jcli3404.1, 2010. Cordero, R. R., Seckmeyer, G., Pissulla, D., Dasilva, L., and Labbe, F.: Uncertainty evaluation of the spectral UV irradiance evaluated by using the UVSPEC radiative transfer model, Opt. Commun., 276, 44–53, http://dx.doi.org10.1016/j.optcom.2007.04.008doi:10.1016/j.optcom.2007.04.008, 2007. de Grandpre, J., Beagley, S. R., Fomichev, V. I., Griffioen, E., McConnell, J. C., Medvedev, A. S., and Shepherd, T. G.: Ozone climatology using interactive chemistry: Results from the Canadian Middle Atmosphere Model, J. Geophys. Res.-Atmos., 105, 26475–26491, 2000. den Outer, P. N., Slaper, H., and Tax, R. B.: UV radiation in the Netherlands: Assessing long-term variability and trends in relation to ozone and clouds, J. Geophys. Res.-Atmos., 110, D02203, doi:02210.01029/02004JD004824, 2005. den Outer, P. N., Slaper, H., Kaurola, J., Lindfors, A., Kazantzidis, A., Bais, A. F., Feister, U., Junk, J., Janouch, M., and Josefsson, W.: Reconstructing of erythemal ultraviolet radiation levels in Europe for the past four decades, J. Geophys. Res.-Atmos., 115, D10102, doi:10110.11029/12009JD012827, 2010. Deque, M.: Frequency of precipitation and temperature extremes over France in an anthropogenic scenario: Model results and statistical correction according to observed values, Global Planet. Change, 57, 16–26, http://dx.doi.org/10.1016/j.gloplacha.2006.11.030doi:10.1016/j.gloplacha.2006.11.030, 2007. Dufresne, J. L. and Bony, S.: An assessment of the primary sources of spread of global warming estimates from coupled atmosphere–ocean models, J. Climate, 21, 5135–5144, http://dx.doi.org/10.1175/2008JCLI2239.1doi:10.1175/2008JCLI2239.1, 2008. Egorova, T., Rozanov, E., Zubov, V., Manzini, E., Schmutz, W., and Peter, T.: Chemistry-climate model SOCOL: a validation of the present-day climatology, Atmos. Chem. Phys., 5, 1557–1576, http://dx.doi.org/10.5194/acp-5-1557-2005doi:10.5194/acp-5-1557-2005, 2005. Engel, A., Mobius, T., Bonisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T., Sugawara, S., Moore, F., Hurst, D., Elkins, J., Schauffler, S., Andrews, A., and Boering, K.: Age of stratospheric air unchanged within uncertainties over the past 30 years, Nat. Geosci., 2, 28–31, http://dx.doi.org/10.1038/Ngeo388doi:10.1038/Ngeo388, 2009. Eyring, V., Butchart, N., Waugh, D. W., Akiyoshi, H., Austin, J., Bekki, S., Bodeker, G. E., Boville, B. A., Brühl, C., Chipperfield, M. P., Cordero, E., Dameris, M., Deushi, M., Fioletov, V. E., Frith, S. M., Garcia, R. R., Gettelman, A., Giorgetta, M. A., Grewe, V., Jourdain, L., Kinnison, D. E., Mancini, E., Manzini, E., Marchand, M., Marsh, D. R., Nagashima, T., Newman, P. A., Nielsen, J. E., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Schraner, M., Shepherd, T. G., Shibata, K., Stolarski, R. S., Struthers, H., Tian, W., and Yoshiki, M.: Assessment of temperature, trace species, and ozone in chemistry-climate model simulations of the recent past, J. Geophys. Res.-Atmos., 111, D22308, doi:22310.21029/22006JD007327, 2006. Eyring, V., Waugh, D. W., Bodeker, G. E., Cordero, E., Akiyoshi, H., Austin, J., Beagley, S. R., Boville, B. A., Braesicke, P., Brühl, C., Butchart, N., Chipperfield, M. P., Dameris, M., Deckert, R., Deushi, M., Frith, S. M., Garcia, R. R., Gettelman, A., Giorgetta, M. A., Kinnison, D. E., Mancini, E., Manzini, E., Marsh, D. R., Matthes, S., Nagashima, T., Newman, P. A., Nielsen, J. E., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Schraner, M., Scinocca, J. F., Semeniuk, K., Shepherd, T. G., Shibata, K., Steil, B., Stolarski, R. S., Tian, W., and Yoshiki, M.: Multi-model projections of stratospheric ozone in the 21st century, J. Geophys. Res.-Atmos., 112, D16303, doi:16310.11029/12006JD008332, 2007. Eyring, V., Chipperfield, M. P., Giorgetta, M. A., Kinnison, D. E., Manzini, E., Matthes, K., Newman, P. A., Pawson, S., Shepherd, T. G., and Waugh, D. W.: Overview of the New CCMVal Reference and Sensitivity Simulations in Support of Upcoming Ozone and Climate Assessments and the Planned SPARC CCMVal Report, SPARC Newsletter No 30, 20–26, 2008. Eyring, V., Cionni, I., Bodeker, G. E., Charlton-Perez, A. J., Kinnison, D. E., Scinocca, J. F., Waugh, D. W., Akiyoshi, H., Bekki, S., Chipperfield, M. P., Dameris, M., Dhomse, S., Frith, S. M., Garny, H., Gettelman, A., Kubin, A., Langematz, U., Mancini, E., Marchand, M., Nakamura, T., Oman, L. D., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Shepherd, T. G., Shibata, K., Tian, W., Braesicke, P., Hardiman, S. C., Lamarque, J. F., Morgenstern, O., Pyle, J. A., Smale, D., and Yamashita, Y.: Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models, Atmos. Chem. Phys., 10, 9451–9472, http://dx.doi.org/10.5194/acp-10-9451-2010doi:10.5194/acp-10-9451-2010, 2010. Fioletov, V. E., McArthur, L. J. B., Kerr, J. B., and Wardle, D. I.: Long-term variations of UV-B irradiance over Canada estimated from Brewer observations and derived from ozone and pyranometer measurements, J. Geophys. Res.-Atmos., 106, 23009–23027, 2001. Garcia, R. R., Marsh, D. R., Kinnison, D. E., Boville, B. A., and Sassi, F.: Simulation of secular trends in the middle atmosphere, 1950–2003, J. Geophys. Res.-Atmos., 112, D09301, doi:09310.01029/02006JD007485, 2007. Garny, H., Dameris, M., and Stenke, A.: Impact of prescribed SSTs on climatologies and long-term trends in CCM simulations, Atmos. Chem. Phys., 9, 6017–6031, http://dx.doi.org/10.5194/acp-9-6017-2009doi:10.5194/acp-9-6017-2009, 2009. Hegglin, M. I. and Shepherd, T. G.: Large climate-induced changes in ultraviolet index and stratosphere-to-troposphere ozone flux, Nat. Geosci., 2, 687–691, http://dx.doi.org/10.1038/Ngeo604doi:10.1038/Ngeo604, 2009. Herman, J. R.: Global increase in UV irradiance during the past 30 years (1979–2008) estimated from satellite data, J. Geophys. Res.-Atmos., 115, D04203, doi:04210.01029/02009JD012219, 2010. Herman, J. R., Larko, D., Celarier, E., and Ziemke, J.: Changes in the Earth's UV reflectivity from the surface, clouds and aerosols, J. Geophys. Res., 106, 5353–5368, 2001. IPCC: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change., Cambridge, UK, 2001, pp 881, 4~March~2002, 2001. IPCC: (Intergovernmental Panel on Climate Change): Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, Cambridge, UK, and New York, NY, 996, 2007. Jöckel, P., Tost, H., Pozzer, A., Brühl, C., Buchholz, J., Ganzeveld, L., Hoor, P., Kerkweg, A., Lawrence, M. G., Sander, R., Steil, B., Stiller, G., Tanarhte, M., Taraborrelli, D., van Aardenne, J., and Lelieveld, J.: The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere, Atmos. Chem. Phys., 6, 5067–5104, http://dx.doi.org/10.5194/acp-6-5067-2006doi:10.5194/acp-6-5067-2006, 2006. Jourdain, L., Bekki, S., Lott, F., and Lefèvre, F.: The coupled chemistry-climate model LMDz-REPROBUS: description and evaluation of a transient simulation of the period 1980-1999, Ann. Geophys., 26, 1391–1413, http://dx.doi.org/10.5194/angeo-26-1391-2008doi:10.5194/angeo-26-1391-2008, 2008. Kaurola, J., Lindfors, A., Lakkala, K., Hansen, G., Josefsson, W., Vuilleumier, L., Feister, U., and Slaper, H.: On the usability of the ERA-40 reanalysis in the estimation of past surface UV radiation over Europe, J. Geophys. Res., 115, D24107, http://dx.doi.org/10.1029/2010jd013810doi:10.1029/2010jd013810, 2010. Kazantzidis, A., Bais, A., Garane, K., Kazadzis, S., and Meleti, C.: Estimation of UV irradiance from ancillary data and comparison with measurements at Thessaloniki, Greece (40.5° N, 23° E), P Soc Photo-Opt Ins, Stockholm, Sweden, 2006. Kazantzidis, A., Bais, A. F., Zempila, M. M., Kazadzis, S., den Outer, P. N., Koskela, T., and Slaper, H.: Calculations of the human vitamin D exposure from UV spectral measurements at three European stations, Photochem. Photobiol. Sci., 8, 45–51, http://dx.doi.org/10.1039/b811216adoi:10.1039/b811216a, 2009. Kinne, S., Schulz, M., Textor, C., Guibert, S., Balkanski, Y., Bauer, S. E., Berntsen, T., Berglen, T. F., Boucher, O., Chin, M., Collins, W., Dentener, F., Diehl, T., Easter, R., Feichter, J., Fillmore, D., Ghan, S., Ginoux, P., Gong, S., Grini, A., Hendricks, J., Herzog, M., Horowitz, L., Isaksen, I., Iversen, T., KirkevÃ¥g, A., Kloster, S., Koch, D., Kristjansson, J. E., Krol, M., Lauer, A., Lamarque, J. F., Lesins, G., Liu, X., Lohmann, U., Montanaro, V., Myhre, G., Penner, J., Pitari, G., Reddy, S., Seland, O., Stier, P., Takemura, T., and Tie, X.: An AeroCom initial assessment - optical properties in aerosol component modules of global models, Atmos. Chem. Phys., 6, 1815–1834, http://dx.doi.org/10.5194/acp-6-1815-2006doi:10.5194/acp-6-1815-2006, 2006. Lamarque, J. F., Kinnison, D. E., Hess, P. G., and Vitt, F. M.: Simulated lower stratospheric trends between 1970 and 2005: Identifying the role of climate and composition changes, J. Geophys. Res.-Atmos., 113, D12301, http://dx.doi.org/10.1029/2007JD009277doi:10.1029/2007JD009277, 2008. Li, F., Stolarski, R. S., and Newman, P. A.: Stratospheric ozone in the post-CFC era, Atmos. Chem. Phys., 9, 2207–2213, http://dx.doi.org/10.5194/acp-9-2207-2009doi:10.5194/acp-9-2207-2009, 2009. Lindfors, A., Kaurola, J., Arola, A., Koskela, T., Lakkala, K., Josefsson, W., Olseth, J. A., and Johnsen, B.: A method for reconstruction of past UV radiation based on radiative transfer modeling: Applied to four stations in northern Europe, J. Geophys. Res., 112, D23201, doi:23210.21029/22007JD008454, 2007. Madronich, S.: Analytic Formula for the Clear-sky UV Index, Photochem. Photobiol. Sci., 83, 1537–1538, http://dx.doi.org/10.1111/j.1751-1097.2007.00200.xdoi:10.1111/j.1751-1097.2007.00200.x, 2007. Mayer, B. and Kylling, A.: Technical note: The libRadtran software package for radiative transfer calculations – description and examples of use, Atmos. Chem. Phys., 5, 1855–1877, http://dx.doi.org/10.5194/acp-5-1855-2005doi:10.5194/acp-5-1855-2005, 2005. McKenzie, R. L., Bjorn, L. O., Bais, A., and Ilyas, M.: Changes in biologically active ultraviolet radiation reaching the Earth's surface (Vol 2, p 5, 2003), Photochem. Photobiol. Sci., 2, 354–354, 2003. McKenzie, R. L., Liley, J. B., and Björn, L. O.: UV Radiation: Balancing Risks and Benefits, Photochem. Photobiol. Sci., 85, 88–98, 2009. McKinlay, A. F. and Diffey, B. L.: A Reference Action Spectrum for Ultra-violet Induced Erythema in Human Skin, in: Human Exposure to Ultraviolet Radiation: Risks and Regulations, edited by: Passchier, W. F. and Bosnajakovic, B. F. M., Elsevier, Amsterdam, 83–87, 1987. McLandress, C. and Shepherd, T. G.: Simulated Anthropogenic Changes in the Brewer-Dobson Circulation, Including Its Extension to High Latitudes, J. Climate, 22, 1516–1540, http://dx.doi.org/10.1175/2008jcli2679.1doi:10.1175/2008jcli2679.1, 2009. McLandress, C., Jonsson, A. I., Plummer, D. A., Reader, M. C., Scinocca, J. F., and Shepherd, T. G.: Separating the Dynamical Effects of Climate Change and Ozone Depletion, Part I: Southern Hemisphere Stratosphere, J. Climate, 23, 5002–5020, http://dx.doi.org/10.1175/2010jcli3586.1doi:10.1175/2010jcli3586.1, 2010. Meinander, O., Kontu, A., Lakkala, K., Heikkilä, A., Ylianttila, L., and Toikka, M.: Diurnal variations in the UV albedo of arctic snow, Atmos. Chem. Phys., 8, 6551–6563, http://dx.doi.org/10.5194/acp-8-6551-2008doi:10.5194/acp-8-6551-2008, 2008. Morgenstern, O., Giorgetta, M. A., Shibata, K., Eyring, V., Waugh, D. W., Shepherd, T. G., Akiyoshi, H., Austin, J., Baumgaertner, A. J. G., Bekki, S., Braesicke, P., Brühl, C., Chipperfield, M. P., Cugnet, D., Dameris, M., Dhomse, S., Frith, S. M., Garny, H., Gettelman, A., Hardiman, S. C., Hegglin, M. I., Jöckel, P., Kinnison, D. E., Lamarque, J. F., Mancini, E., Manzini, E., Marchand, M., Michou, M., Nakamura, T., Nielsen, J. E., Olivié, D., Pitari, G., Plummer, D. A., Rozanov, E., Scinocca, J. F., Smale, D., Teyssèdre, H., Toohey, M., Tian, W., and Yamashita, Y.: Review of the formulation of present-generation stratospheric chemistry-climate models and associated external forcings, J. Geophys. Res.-Atmos., 115, D00M02, http://dx.doi.org/10.1029/2009jd013728doi:10.1029/2009jd013728, 2010. Nissen, K. M., Matthes, K., Langematz, U., and Mayer, B.: Towards a better representation of the solar cycle in general circulation models, Atmos. Chem. Phys., 7, 5391–5400, http://dx.doi.org/10.5194/acp-7-5391-2007doi:10.5194/acp-7-5391-2007, 2007. Overland, J. E. and Wang, M.: Future regional Arctic sea ice declines, Geophys. Res. Lett., 34, L17705, doi:17710.11029/12007GL030808, 2007. Pawson, S., Stolarski, R. S., Douglass, A. R., Newman, P. A., Nielsen, J. E., Frith, S. H., and Gupta, M. L.: Goddard Earth Observing System Chemistry-Climate Model Simulations of Stratospheric Ozone-Temperature Coupling Between 1950 and 2005, J. Geophys. Res.-Atmos., 113, D12103, doi:12110.11029/12007JD009511, 2008. Pitari, G., Mancini, E., Rizi, V., and Shindell, D.: Impact of future climate and sulfur emission changes on stratospheric aerosols and ozone, J. Atmos. Sci., 59, 414–440, 2002. Schraner, M., Rozanov, E., Schnadt Poberaj, C., Kenzelmann, P., Fischer, A. M., Zubov, V., Luo, B. P., Hoyle, C. R., Egorova, T., Fueglistaler, S., Brönnimann, S., Schmutz, W., and Peter, T.: Technical Note: Chemistry-climate model SOCOL: version 2.0 with improved transport and chemistry/microphysics schemes, Atmos. Chem. Phys., 8, 5957–5974, http://dx.doi.org/10.5194/acp-8-5957-2008doi:10.5194/acp-8-5957-2008, 2008. Scinocca, J. F., McFarlane, N. A., Lazare, M., Li, J., and Plummer, D.: Technical Note: The CCCma third generation AGCM and its extension into the middle atmosphere, Atmos. Chem. Phys., 8, 7055–7074, http://dx.doi.org/10.5194/acp-8-7055-2008doi:10.5194/acp-8-7055-2008, 2008. Seckmeyer, G., Erb, R., and Albold, A.: Transmittance of a cloud is wavelength-dependent in the UV- range, Geophys. Res. Lett., 23, 2753–2755, 1996. Shepherd, T. G.: Dynamics, stratospheric ozone, and climate change, Atmos. Ocean, 46, 117–138, 2008. Shibata, K. and Deushi, M.: Long-term variations and trends in the simulation of the middle atmosphere 1980-2004 by the chemistry-climate model of the Meteorological Research Institute, Ann. Geophys., 26, 1299–1326, 2008. Son, S.-W., Tandon, N. F., Polvani, L. M., and Waugh, D. W.: Ozone hole and Southern Hemisphere climate change, Geophys. Res. Lett., 36, L15705, http://dx.doi.org/10.1029/2009GL038671doi:10.1029/2009GL038671, 2009. SPARC_CCMVal: SPARC Report on the Evaluation of Chemistry-Climate Models, Stratospheric Processes And their Role in Climate (SPARC) Report No 5, WCRP-132, WMO/TD-No 1526, available: http://www.atmosp.physics.utoronto.ca/SPARC, edited by: Eyring, V., Shepherd, T. G., and Waugh, D. W., WMO, Geneva, 2010. Staiger, H., den Outer, P. N., Bais, A. F., Feister, U., Johnsen, B., and Vuilleumier, L.: Hourly resolved cloud modification factors in the ultraviolet, Atmos. Chem. Phys., 8, 2493–2508, http://dx.doi.org/10.5194/acp-8-2493-2008doi:10.5194/acp-8-2493-2008, 2008. Stenke, A., Dameris, M., Grewe, V., and Garny, H.: Implications of Lagrangian transport for simulations with a coupled chemistry-climate model, Atmos. Chem. Phys., 9, 5489–5504, http://dx.doi.org/10.5194/acp-9-5489-2009doi:10.5194/acp-9-5489-2009, 2009. Teyssèdre, H., Michou, M., Clark, H. L., Josse, B., Karcher, F., Olivié, D., Peuch, V.-H., Saint-Martin, D., Cariolle, D., Attié, J.-L., Nédélec, P., Ricaud, P., Thouret, V., van der A, R. J., Volz-Thomas, A., and Chéroux, F.: A new tropospheric and stratospheric Chemistry and Transport Model MOCAGE-Climat for multi-year studies: evaluation of the present-day climatology and sensitivity to surface processes, Atmos. Chem. Phys., 7, 5815–5860, http://dx.doi.org/10.5194/acp-7-5815-2007doi:10.5194/acp-7-5815-2007, 2007. Tian, W. and Chipperfield, M. P.: A new coupled chemistry – climate model for the stratosphere: The importance of coupling for future O<sub>3</sub>-climate predictions, Q. J. Roy. Meteorol. Soc., 131, 281–304, 2005. Tian, W. S., Chipperfield, M. P., Gray, L. J., and Zawodny, J. M.: Quasi-biennial oscillation and tracer distributions in a coupled chemistry-climate model, J. Geophys. Res.-Atmos., 111, D20301, http://dx.doi.org/10.1029/2005JD006871doi:10.1029/2005JD006871, 2006. Tourpali, K., Bais, A. F., Kazantzidis, A., Zerefos, C. S., Akiyoshi, H., Austin, J., Brühl, C., Butchart, N., Chipperfield, M. P., Dameris, M., Deushi, M., Eyring, V., Giorgetta, M. A., Kinnison, D. E., Mancini, E., Marsh, D. R., Nagashima, T., Pitari, G., Plummer, D. A., Rozanov, E., Shibata, K., and Tian, W.: Clear sky UV simulations for the 21st century based on ozone and temperature projections from Chemistry-Climate Models, Atmos. Chem. Phys., 9, 1165–1172, http://dx.doi.org/10.5194/acp-9-1165-2009doi:10.5194/acp-9-1165-2009, 2009. UNEP: Environmental effects of ozone depletion and its interaction with climate change: 2006 assessment, United Nations Environment Programme (UNEP), Nairobi, 206, 2006. UNEP: Environmental effects of ozone depletion and its interaction with climate change: 2010 assessment, United Nations Environment Programme (UNEP), Nairobi, 278, 2010. Waugh, D. W., Oman, L., Kawa, S. R., Stolarski, R. S., Pawson, S., Douglass, A. R., Newman, P. A., and Nielsen, J. E.: Impacts of climate change on stratospheric ozone recovery, Geophys. Res. Lett., 36, L03805, doi:03810.01029/02008GL036223, 2009. Webb, A. R. and Engelsen, O.: Calculated ultraviolet exposure levels for a healthy vitamin D status, Photochem. Photobiol. Sci., 82, 1697–1703, 2006. Weihs, P. and Webb, A. R.: Accuracy of spectral UV model calculations 1. Consideration of uncertainties in input parameters, J. Geophys. Res., 102, 1541–1550, 1997. WMO: Scientific Assessment of Ozone Depletion: 2002, World Meteorological Organisation, Geneva, Global Ozone Research and Monitoring Project – Report No 47, 498, 2003. WMO: (World Meteorological Organization): Scientific Assessment of Ozone Depletion: 2006, World Meteorological Organisation, Geneva, Switzerland Global ozone Research and Monitoring Project – Report No 50, 572, 2007. WMO: (World Meteorological Organization): Scientific Assessment of Ozone Depletion: 2010, World Meteorological Organisation, Geneva, Switzerland Global ozone Research and Monitoring Project – Report No 52, 438, 2011. Wuttke, S., Seckmeyer, G., and Koenig-Langlo, G.: Measurements of spectral snow albedo at Neumayer, Antarctica, Ann. Geophys., 24, 7–21, 2006.