The effect of clouds on enhancing UVB irradiance at the earth's surface: a one year study

Sabburg, J. and Wong, J. (2000) The effect of clouds on enhancing UVB irradiance at the earth's surface: a one year study. Geophysical Research Letters, 27 (20). pp. 3337-3340. ISSN 0094-8276


The most extensive study of frequency, magnitude and sky properties associated with UVB enhancement is reported. The first integrated automatic sky camera and irradiance measurement system was used for simultaneous data collection over the solar zenith angle range of 4.2 to 64.3°. It is reported that 3% of UVB irradiance measurements collected at intervals of 6 minutes, over a one-year period, were cloud enhanced. It was found that 85% of possible UVB enhancements occurred for solar zenith angles ranging from 40 to 63°. The study was undertaken during September 1997 to August 1998 at Toowoomba, Australia (27.6°S, 151.9°E). The maximum UVB enhancement was found to have an irradiance of 8% greater than that of an equivalent clear-sky. A mechanism for UVB enhancement for cases of solar obstruction by cirrus cloud is postulated. Analysis showed that 86% of enhancement occurred under hazy/cirrus skies.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty / Department / School: Historic - Faculty of Sciences - No Department
Date Deposited: 30 Nov 2007 11:47
Last Modified: 14 Nov 2013 02:19
Uncontrolled Keywords: clouds; solar radiation; ultraviolet radiation
Fields of Research : 04 Earth Sciences > 0401 Atmospheric Sciences > 040106 Cloud Physics
04 Earth Sciences > 0401 Atmospheric Sciences > 040103 Atmospheric Radiation
02 Physical Sciences > 0299 Other Physical Sciences > 029904 Synchrotrons; Accelerators; Instruments and Techniques
Socio-Economic Objective: D Environment > 96 Environment > 9602 Atmosphere and Weather > 960202 Atmospheric Processes and Dynamics
Identification Number or DOI: 10.1029/2000GL011683

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