ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-6309-2008 Reconstruction of erythemal UV-doses for two stations in Austria: a comparison between alpine and urban regions Rieder H. E. 1 2 6 Holawe F. 2 Simic S. 1 Blumthaler M. 3 Krzyścin J. W. 4 Wagner J. E. 1 Schmalwieser A. W. 5 Weihs P. 1 Institute for Meteorology, University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Austria Institute for Geography and Regional Research, University of Vienna, Vienna, Austria Division for Biomedical Physics, Innsbruck Medical University, Innsbruck, Austria Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland Institute of Medical Physics and Biostatistics, University of Veterinary Medicine Vienna, Vienna, Austria now at: Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland 31 10 2008 8 20 6309 6323 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/8/6309/2008/acp-8-6309-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/6309/2008/acp-8-6309-2008.pdf

The aim of this study is the reconstruction of past UV-doses for two stations in Austria, Hoher Sonnblick and Vienna, using a physical radiation transfer model. The method uses the modeled UV-dose under clear-sky conditions, cloud modification factors and a correction factor as input variables. To identify the influence of temporal resolution of input data and modification factors, an ensemble of four different modelling approaches was calculated, each with hourly or daily resolution. This is especially important because we found no other study describing the influence of the temporal resolution of input data on model performance. Following the results of the statistical analysis of the evaluation period the model with the highest temporal resolution (HMC) was chosen for the reconstruction of UV-doses. A good agreement between modelled and measured values of erythemally effective UV-doses was found at both stations. In relation to the reference period 1976–1985 an increase in the erythemal UV-dose in Vienna of 11% is visible in the period 1986–1995 and an increase of 17% in the period 1996–2005 can be seen. At Hoher Sonnblick the corresponding increase is 2% and 9%. For the different seasons the strongest increase in erythemal UV-dose has been found for winter and spring season at both stations. Further the influences of total ozone and cloudiness on changes in erythemal UV-doses were analyzed. This analysis showed for both stations, that changes in total ozone had a larger influence on erythemal UV-doses than changes in cloudiness.

 References Ångstroem, A.: On the Atmospheric Transmission of Sun Radiation and on Dust in the Air, Geografiska Annaler, 11, 156–166, 1929. Blumthaler, M. and Ambach, W.: Solar UVB-albedo of various surfaces, Photochem. Photobiol., 48, 85–88, 1988. Blumthaler, M.: Quality assurance and quality control methodologies within the Austrian UV monitoring network, Rad. Prot. Dos., 111, 359–362, 2004. Brewer, A. W.: A replacement for the Dobson spectrophotometer?, Pure Appl. Geophys., 106–108, 919–927, 1973. Burrows, W. R.: CART regression models for predicting UV radiation at the ground in the presence of cloud and other environmental factors, J. Appl. Meteorol., 36, 531–544, 1997. Calbó, J., Pagès, D., and González, J.-A.: Empirical studies of cloud effects on UV radiation: a review, Rev. Geophys., 43, 155–183, 2005. Cheymol, A. and De Backer, H.: Retrieval of the aerosol optical depth in the UV-B at Uccle from Brewer ozone measurements over a long time period 1984–2002, J. Geophys. Res., 108(D24), 4800, doi:10.1029/2003JD003758, 2003. Commission Internationale de l'Eclairage (CIE): 134/1, TC 6-26 Report: Standardization of the terms UV-A1, UV-A2 and UV-B, in Collection in Photobiology and Photochemistry, Comm. Int. de l'Eclairage, Vienna, 1999. 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., 110, D02203, doi:10.1029/2004JD004824, 2005. Dobson, G. M. B.: A photoelectric spectrophotometer for measuring the amount of atmospheric ozone, Proc. Phys. Soc. London, 43, 324–337, 1931. Farman, J. C., Gardiner, B. G., and Shanklin, J. D.: Large losses of total ozone in Antarctica reveal seasonal \chemClO_x/NO<sub>x</sub> interaction, Nature, 315, 207–210, 1985. 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., 106(D19), 23 009–23 028, doi:10.1029/2001JD000367, 2001. Gantner, L., Winkler, P., and Köhler, U.: A method to derive long-term time series and trends of UV-B radiation (1968–1997) from observations at Hohenpeissenberg (Bavaria), J. Geophys. Res., 105(D4), 4879–4888, doi:10.1029/1999JD900907, 2000. Gleason, J. F., Bhartia, P. K., and Herman, J. R.: Record low global ozone in 1992, Science, 260, 523–526, 1993. International Agency for Research on Cancer: Solar and Ultraviolet Radiation, Monogr. Eval. Carcinogenic Risks Hum., 55 , 336 pp., Geneva, Switzerland, 1992. International Program on Chemical Safety (IPCS): Ultraviolet Radiation. Environmental Criteria, 160, World Health Organization, Geneva, Switzerland, 1994. Kaurola, J., Taalas, P., Koskela, T., Borkowski, J., Josefsson, W.: Long-term variations of UV-B doses at three stations in northern Europe, J. Geophys. Res., 105(D16), 20 813–20 820, doi:10.1029/2000JD900258, 2000. Kazadzis, S., Bais, A., Amiridis, V., Balis, D., Meleti, C., Kouremeti, N., Zerefos, C. S., Rapsomanikis, S., Petrakakis, M., Kelesis, A., Tzoumaka, P., and Kelektsoglou, K.: Nine years of UV aerosol optical depth measurements at Thessaloniki, Greece, Atmos. Chem. Phys., 7, 2091–2101, 2007. Kerr, J. B. and McElroy, C. T.: Total ozone measurements made with the Brewer ozone spectrophotometer during STOIC 1989, J. Geophys. Res., 100(D5), 9225–9230, doi:10.1029/94JD02147, 1995. Kerr, J. B.: Understanding the factors that effect surface UV radiation, Proc. of SPIE, 5156, 1–14, 2003. Koepke, P., De Backer, H., Bais, A., Curylo, A., Eerme, K., Feister, U., Johnsen, B., Junk, J., Kazantzidis, A., Krzyscin, J., Lindfors, A., Olseth, J. A., den Outer, P, Pribullova, A., Schmalwieser, A., Slaper, H., Staiger, H., Verdebout, J., Vuilleumier, Komyhr, W. D.: Operations handbook – Ozone observations with a Dobson spectrophotometer, Global Ozone, Research and Monitoring Project Report 6 – WMO, Geneva, Switzerland, 1980. Krzy\'scin, J. W.: Statistical reconstruction of daily total ozone over Europe 1950 to 2004, J. Geophys. Res., 113, D07112, doi:10.1029/2007JD008881, 2008. Kylling, A., Dahlback, A., and Mayer, B.: The effect of clouds and surface albedo on UV irradiances at a high latitude site, Geophys. Res. Lett., 27(9), 1411–1414, doi:10.1029/1999GL011015, 2000. Lindfors, A., Arola, A., Kaurola, J., Taalas, P., and Svenøe, T.: Long-term erythemal UV doses at Sodankylä estimated using total ozone, sunshine duration and snow depth, J. Geophys. Res., 108(D16), 4518, doi:10.1029/2002JD003325, 2003. Lindfors, A. and Vuilleumier, L.: Erythemal UV at Davos (Switzerland), 1926–2003, estimated using total ozone, sunshine duration, and snow depth, J. Geophys. Res., 110, D02104, doi:10.1029/2004JD005231, 2005. Longstreth, I., de Gruijl, F. R., Kripke, M. L., Abseck, S., Arnold, F., Slaper, H., Velders, G., Takizawa, Y., and van der Leun, J. C.: Health risks, J. Photochem. Photobiol. B, 46, 20–33, 1998. Makowski, K., Wild, M., and Ohmura, A.: Diurnal temperature range over Europe between 1950 and 2005, Atmos. Chem. Phys. Discuss., 8, 7051–7084, 2008. Matthijsen, J., Slaper, H., and Reinen, H. A. J. M.: Reduction of solar UV by clouds: A comparison between satellite-derived cloud effects and ground-based radiation measurements, J. Geophys. Res., 105(D4), 5069–5080, doi:10.1029/1999JD900937, 2000. McKenzie, R. L., Madronich, S., and Paulin, K. J.: Effects of snow cover on UV irradiance and surface albedo: A case study, J. Geophys. Res., 103(D22), 28 785–28 792, do:10.1029/98JD02704, 1998. Moan, J., Dahlback, A., and Setlow, R. B.: Epidemiological support for an hypothesis for melanoma induction indicating a role for UVA radiation, Photchem. Photobiol., 70, 243–247, 1999. National Radiological Protection Board: Health effects from ultraviolet radiation, Report of an advisory group on non-ionising radiation, Doc. NRP, 13, p 1, UK, 2002. Neuwirth, F.: Beziehungen zwischen den Monatswerten der Globalstrahlung und der Sonnenscheindauer in Österreich, Arch. Met. Geoph. Biokl., Ser. B, 26, 171–182, 1978. Nicolet, M.: On the molecular scattering in the terrestrial atmosphere: an empirical formula for its calculation in the homosphere, Planet. Space Sci., 32, 1467–1468. Reuder, J. and Koepke, P.: Reconstruction of UV radiation over Southern Germany for the past decades, Meteorol. Z., 14(2), 237–246, 2005. Ruckstuhl., C., Philipona, R., Behrens, K., Collaud Coen, M., Dürr., B., Heimo, A., Mätzler, C., Nyeki, S., Ohmura, A., Vuilleumier, L., Weller, M., Wehrli, C., and Zelenka, A.: Aerosol and cloud effects on solar brightening and the recent rapid warming, Geophys. Res. Lett., 35, L12708, doi:10.1029/200GL034228, 2008. Schmalwieser, A. W. and Schauberger, G.: A monitoring network for erythemally-effective solar ultraviolet radiation in Austria: determination of the measuring sites and visualisation of the spatial distribution, Theor. Appl. Climatol., 69, 221–229, 2001. Schmucki, D. A. and Philipona, R.: Ultraviolet radiation in the alps: The altitude effect, Opt. Eng., 41, 3090–3095, 2002. Schwander, H., Koepke, P., and Ruggaber, A.: Uncertainties in modeled UV irradiances due to limited accurancy and availability of input data, J. Geophys. Res., 102(D8), 9419–9430, doi:10.1029/97JD00244, 1997. Schwander, H., Koepke, P., Kaifel, A., and Seckmeyer, G.: Modification of spectral UV irradiance by clouds, J. Geophys. Res., 107(D16), 4319, doi:10.1029/2001JD001297, 2002. Seckmeyer, G., Mayer, B., Bernhard, G., McKenzie, R. L., Johnston, P. V., Kotkamp, M., Booth, C.R., Lucas, T., Mestechkina, T., Roy, C. R., Gies, H. P., Tomlinson, D.: Geographical differences in the UV measured by intercompared spectroradiometers, Geophys. Res. Lett., 22(14), 1889–1892, doi:10.1029/95GL01352, 1995. Setlow, R. B.: Wavelengths in sunlight effective in producing skin cancer – theoretical analysis, Proc. Nat. Ac. Sci. Am., 71, 9, 3363–-3366, 1974. Simic, S., Weihs, P., Kromp-Kolb, H., Vacek, A., and Laube, W.: Factors affecting changes of spectral UV irradiance at the Sonnblick Observatory (3106 m, Austria), Proc. SPIE, 5979, 597927-1–597927-9, 2005. Slaper, H., Velders, G. J. M., Daniel, J. S., deGruijl, F. R., and van der Leun, J. C.: Estimates of ozone depletion and skin cancer incidence to examine the Vienna Convention achievements, Nature, 384, 256–258, 1996. Staehelin, J., Kegel, R., and Harris, N. R.: Trend analysis of the homogenized total ozone series of Arosa (Switzerland), 1929–1996, J. Geophys. Res., 103(D7), 8389–8400, doi:10.1029/97JD03650, 1998a. Staehelin, J., Renaud, A., Bader, J., McPeters, R., Viatte, P., Hoegger, B., Bugnion, V., Giroud, M., and Schill, H.: Total ozone series at Arosa (Switzerland): Homogenization and data comparison, J. Geophys. Res., 103(D5), 5827–5842, doi:10.1029/97JD02402, 1998b. Stamnes, K., Tsay, S. C., Wiscombe, W., and Jayaweera, K.: Numerically stable algorithmn for discrete-ordinate-method radiative transfer in multible scattering and emitting layered media, Appl. Opt., 27, 2502–2509, 1988. Stolarski, R. S., Bloomfield, P., Peters, R. D. M., and Herman, J. R.: Total ozone trends deduced from Nimbus 7 TOMS data, Geophys. Res. Lett., 18(6), 1015–1018, doi:10.1029/91GL01302, 1991. Tegen, I., Koch D., Lacis, A. A., and Sato, M.: Trends in tropospheric aerosol loads and corresponding impact on direct radiative forcing between 1950 and 1990: A model study, J. Geophys. Res., 105(D22), 26 971–26 990, doi:10.1029/2000JD900280, 2000. Thiel, S., Steiner, K., and Seidlitz, H. K.: Modification of global erythemally effective irradiance by clouds, Photchem. Photobiol., 65, 6, 969–973, 1997. United Nations Environment Program (UNEP): Scientific Assessment on ozone depletion, Global Ozone Research and Monitoring Project, Report No 47, 498~pp., Geneva, 2002. United Nations Environment Program (UNEP): Environmental effects of ozone depletion: 1998 assessment, Nairobi, Kenya, 1998. Vanicek, K., Frei, T., Litynska, Z., and Schmalwieser, A.: UV-index for the public: A guide for publication and interpretation of solar UV index forecasts for the public prepared by the Working Group 4 of the COST-713 action "UVB forecasting", Eur. Coop. Field Sci. Tech. Res., Brussels, 2000. Weihs, P. and Webb, A.: Accuracy of spectral UV model calculations: 1 – Consideration of uncertainties in input parameters, J. Geophys. Res., 102(D1), 1541–1550, doi:10.1029/96JD01242, 1997. Weihs, P. and Webb, A.: Accuracy of spectral UV model calculations: 2 – Comparison of UV calculations with measurements, J. Geophys. Res., 102(D1), 1551–1560, doi:10.1029/96JD02621, 1997. Weihs, P., Simic, S., Laube, W., Mikielewicz, W., Rengarajan, G., and Mandl, G.: Albedo influences on surface UV irradiance at the Sonnblick high mountain Observatory (3106 m altitude), J. Appl. Meteorol., 38, 1599–1610, 1999. Weihs, P., Lenoble, J., Blumthaler, M., Martin, T., Seckmeyer, G., Philipona, R., De la Casiniere, A., Sergent, C., Gröbner, J., Cabot, T., Masserot, D., Pichler, T., Pougatch, E., Rengarajan, G., Schmucki, D., and Simic S.: Modelling the effect of an inhomogeneous surface albedo on incident UV radiation in mountainous terrain: Determination of an effective surface albedo, Geophys. Res. Lett., 28(16), 3111–3114, doi:10.1029/2001GL012986, 2001. Weihs, P.: Modelling solar UV radiation in the past: algorithms and input data, Proc. SPIE, 6362, 1–11, 2006. Woodhead, A. D., Setlow, R. B., and Tanaka, M.: Environmental factors in nonmelanoma and melanoma skin cancer, J. Epidemiol., 9, 102–114, 1999. World Health Organization (WHO): Environmental Health Criteria 160 – Ultraviolet radiation, 1994. World Health Organization (WHO): Global Solar UV Index – A practical guide, 2002. World Health Organization (WHO): Environmental Burden of Disease Series No. 13 – Solar Ultraviolet radiation, 2006.