Empirical Evaluation of Global Vitamin D Effective Ultraviolet Irradiances under Cloudy Conditions for a Subtropical Southern Hemisphere Site

doi: 10.1667/RR1936.1
Radiation Research 173(5):703-708. 2010
David J. Turnbull1, Alfio V. Parisi, and Peter W. Schouten
Centre for Rural and Remote Area Health, University of Southern Queensland, Toowoomba, Queensland 4350, Australia
Turnbull, D. J., Parisi, A. V. and Schouten, P. W. Empirical Evaluation of Global Vitamin D Effective Ultraviolet Irradiances under Cloudy Conditions for a Subtropical Southern Hemisphere Site.
1Address for correspondence: Centre for Rural and Remote Area Health, University of Southern Queensland, Toowoomba, 4350, Australia; e-mail: turnbull at usq.edu.au.

This paper evaluates the global vitamin D effective UV (UVvitd) irradiances under cloudy conditions at a subtropical, southern hemisphere site. The UVvitd irradiances were analyzed on a horizontal plane and sampled at 5-min intervals over 18 months so that a wide range of parameters including cloud conditions, solar zenith angles (SZA) and ozone levels were taken into account. Cloud modification factors were determined from the influence of clouds on the global broadband solar radiation, and these were applied to the cloud-free vitamin D effective UV irradiance to evaluate the UVvitd irradiances on a horizontal plane for cloudy conditions.

For vitamin D effective UV irradiance, cloud modification factors were found to range from 0.9 to 1.0 for no cloud and 0.4 to 0.5 for 8 octa of cloud cover. SZA played a minimal role in this variation. A comparison of the measured and calculated UV vitd irradiances for the 2004 data set in the range of SZA of 70° or less provided an R2 value of 0.90. The output of the model was compared to data measured during the first 6 months of 2005 for an SZA of 70° or less and provided an R2 value of approximately 0.82.

Received: July 22, 2009; Accepted: October 31, 2009

REFERENCES

1. Bordewijk, J. A., H. Slaper, H. A. J. M. Reinen, and E. Schlamann. Total solar radiation and the influence of clouds and aerosols on the biologically effective UV. Geophys. Res. Lett 22:2151–2154. 1995. CrossRef, CSA
2. Blumthaler, M., W. Ambach, and R. Ellinger. Increase in solar UV radiation with altitude. J. Photochem. Photobiol. B Biol 39:130–134. 1997. CrossRef
3. WMO Scientific Assessment of Ozone Depletion: 1998 Global Ozone Research and Monitoring Project, Report No. 44, World Meteorological Organization, Geneva,. 1998.
4. Parisi, A. V., J. Sabburg, J. Turner, and P. K. Dunn. Cloud observations for the statistical evaluation of the UV index at Toowoomba, Australia. Int. J. Biomet 52:159–166. 2008. CrossRef, PubMed
5. Parisi, A. V., D. J. Turnbull, and J. Turner. Calculation of cloud modification factors for the horizontal plane eye damaging ultraviolet radiation. Atmos. Res 86:278–285. 2007. CrossRef
6. Staiger, H., P. N. den Outer, A. F. Bais, U. Feister, B. Johnsen, and L. Vuilleumier. Hourly resolved cloud modification factors in the ultraviolet. Atmos. Chem. Phys 8:2493–2508. 2008. CrossRef
7. Büttner, K. Physik. Bioklimat, Leipzig, 1938. (quoted in M. L. Nack and A. E. S. Green, Influence of clouds, haze, and smog on the middle ultraviolet reaching the ground. Appl. Opt 13:2405–2415. 1974. CrossRef, PubMed, CSA
8. Grant, R. H. and G. M. Heisler. Estimation of ultraviolet-B irradiance under variable cloud conditions. J. Appl. Meterol 39:904–916. 2000. CrossRef, CSA
9. Geogdzhaev, I. V., T. V. Kondranin, N. E. Chubarova, and A. N. Rublev. Comparison of UV measurements and modelling under broken cloudiness. In. Current Problems in Atmosphere Radiation. (W. L. Smith and K. Stamnes, Eds.),. A. Deepak Publishing. Hampton. 1996.
10. Kylling, A., K. Stamnes, and S-C. Tsay. A reliable and efficient two-stream algorithm for spherical radiative transfer: Documentation of accuracy in realistic layered media. J. Atmos. Chem 21:115–150. 1995. CrossRef, CSA
11. Charache, D. H., V. J. Abreu, W. R. Kuhn, and W. R. Skinner. Incorporation of multiple cloud layers for ultraviolet radiation modelling studies. J. Geophys. Res 99:23031–23039. 1994. CrossRef, CSA
12. Sabburg, J. and J. Wong. Evaluation of a sky/cloud formula for estimating UV-B irradiance under cloudy skies. J. Geophys. Res 105:29685–29292. 2000. CrossRef, CSA
13. Schafer, J. S., V. K. Saxena, B. N. Wenny, W. Barnard, and J. J. De Luisi. Observed influence of clouds on ultraviolet-B radiation. Geophys. Res. Lett 23:2625–2628. 1996. CrossRef, CSA
14. Kuchinke, C. and M. Nunez. Cloud transmission estimates of UVB erythemal irradiance. Theor. Appl. Climatol 66:149–161. 1999. CrossRef
15. Renaud, A., J. Staehelin, C. Frohlich, R. Philipona, and A. Heimo. Influence of snow and clouds on erythemal UV radiation: Analysis of Swiss measurements and comparison with models. J. Geophys. Res 105:4961–4969. 2000. CrossRef, CSA
16. Foyo-Moreno, I., J. Vida, and L. Alados-Arboledas. On the use of a cloud modification factor for solar (290–383 nm) spectral range. Theor. Appl. Meteorol 38:1020–1026. 2001. CrossRef
17. Krzyscin, J. W., J. Jaroslawski, and P. S. Sobolewski. Effects of clouds on the surface erythemal irradiance at northern midlatitudes: estimation from the observations taken at Belsk, Poland (1999–2001). J. Atmos. Sol. Terrest. Phys 65:457–467. 2003. CrossRef, CSA
18. Adam, M. E. N. and S. M. El Shazly. Attenuation of UV-B radiation in the atmosphere: Clouds effect, at Quena (Egypt). Atmos. Environ 41:4856–4864. 2007. CrossRef
19. Esteve, A. R., M. J. Marin, F. Tena, M. P. Utrillas, and J. A. Martinez-Lozano. Influence of cloudiness over the values of erythemal radiation in Valencia, Spain. Int. J. Climatol DOI: 10.1002/joc.1883. 2009.
20. Kasten, F. and G. Czeplak. Solar and terrestrial radiation dependent on the amount and type of cloud. Sol. Energy 24:177–189. 1980. CrossRef
21. Blumthaler, M., W. Ambach, and M. Salzgeber. Effect of cloudiness on global and diffuse UV irradiance in a high-mountain area. Theor. Appl. Climatol 50:68–74. 1994. CrossRef
22. Davies, J. A. Comparison of modelled of observed global irradiance. J. Appl. Meteorol 35:192–201. 1995. CrossRef, CSA
23. Alados, I., F. J. Olmo, I. Foyo-Moreno, and L. Alados-Arboledas. Estimation of photosynthetically active radiation under cloudy conditions. Agric. For. Meteorol 102:39–50. 2000. CrossRef, CSA
24. Holick, M. F. Vitamin D deficiency. N. Engl. J. Med 357:266–281. 2007. CrossRef, PubMed
25. Garland, C. F., F. C. Garland, E. D. Gorham, M. Lipkin, H. Newmark, S. B. Mohr, and M. F. Holick. The role of vitamin D in cancer prevention. Am. J. Public Health 96:252–261. 2006. CrossRef, PubMed
26. Foss, Y. J. Vitamin D deficiency is the cause of common obesity. Med. Hypotheses 72:314–321. 2009. CrossRef, PubMed
27. Parisi, A. V. and N. Downs. Cloud cover and horizontal plane eye damaging solar UV exposures. Int. J. Biometeorol 49:130–136. 2004. CrossRef, PubMed
28. CIE (International Commission on Illumination) Action Spectrum for the Production of Previtamin D3 in Human Skin. CIE 174:2006, International Commission on Illumination. Vienna. 2006.
29. Sabburg, J. and A. V. Parisi. Spectral dependency of cloud enhanced UV irradiance. Atmos. Res 81:206–214. 2006. CrossRef
30. Foyo-Moreno, I., I. Alados, F. J. Olmo, and L. Alados-Arboledas. The influence of cloudiness on UV global irradiance (295–385 nm). Agric. For. Meteorol 120:101–111. 2003. CrossRef
31. Pfister, G., R. L. McKenzie, J. B. Liley, A. Thomas, B. W. Forgan, and C. N. Long. Cloud coverage based on all-sky imaging and its impact on surface solar irradiance. J. Appl. Meteorol 42:1421–1434. 2003. CrossRef, CSA
32. Sabburg, J., A. V. Parisi, and M. G. Kimlin. Enhanced spectral UV irradiance: a one year preliminary study. Atmos. Res 66:261–272. 2003. CrossRef, CSA
33. Engelsen, O., M. Brustad, L. Aksnes, and E. Lund. Daily duration of vitamin D synthesis in human skin with relation to latitude, total ozone, altitude, ground cover, aerosols and cloud thickness. Photochem. Photobiol 81:1287–1290. 2005. BioOne, PubMed

Abbreviations used:

CMF: cloud modification factor,
DU: Dobson unit,
SZA: solar zenith angle,
UVvitd; ultraviolet radiation for vitamin D3 synthesis.

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