Empirical evaluation of global vitamin D effective ultraviolet irradiances under cloudy conditions for a sub-tropical southern hemisphere site

Turnbull, David J. and Parisi, Alfio V. and Schouten, Peter W. (2010) Empirical evaluation of global vitamin D effective ultraviolet irradiances under cloudy conditions for a sub-tropical southern hemisphere site. Radiation Research, 173 (5). pp. 703-708. ISSN 0033-7587

Abstract

This paper evaluates the global vitamin D effective UV (UVvitd) irradiances under cloudy conditions at a sub-tropical, southern hemisphere site. The UVvitd irradiances were analysed on a horizontal plane and sampled at five minute intervals over an extended 18 month period 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 to evaluate the UVvitd irradiances on a horizontal plane for cloudy conditions. For vitamin D effective UV, 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 UVvitd 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 against 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.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to paper due to publisher copyright restrictions.
Depositing User: Dr David Turnbull
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 27 May 2010 02:38
Last Modified: 02 Jul 2013 23:44
Uncontrolled Keywords: vitamin D; cloud; ultraviolet radiation
Fields of Research (FOR2008): 04 Earth Sciences > 0401 Atmospheric Sciences > 040107 Meteorology
02 Physical Sciences > 0299 Other Physical Sciences > 029999 Physical Sciences not elsewhere classified
04 Earth Sciences > 0401 Atmospheric Sciences > 040103 Atmospheric Radiation
Socio-Economic Objective (SEO2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
Identification Number or DOI: doi: 10.1667/RR1936.1
URI: http://eprints.usq.edu.au/id/eprint/7251

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