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| Titel |
The influence of the spatial resolution of topographic input data on the accuracy of 3-D UV actinic flux and irradiance calculations |
| VerfasserIn |
P. Weihs, J. E. Wagner, S. F. Schreier, H. E. Rieder, F. Angelini, M. Blumthaler, M. Fitzka, G. P. Gobbi, R. Kift, A. Kreuter, S. Simic, A. R. Webb |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 5 ; Nr. 12, no. 5 (2012-03-01), S.2297-2312 |
| Datensatznummer |
250010846
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| Publikation (Nr.) |
 copernicus.org/acp-12-2297-2012.pdf |
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| Zusammenfassung |
| The aim of this study is to investigate the influence of the spatial
resolution of a digital elevation map (DEM) on the three-dimensional (3-D)
radiative transfer performance for both spectral ultraviolet (UV) irradiance
and actinic flux at 305 nm. Model simulations were performed for clear sky
conditions for three case studies: the first and second one using three
sites in the Innsbruck area and the third one using three sites at the
Sonnblick observatory and surrounding area. It was found that the DEM
resolution may change the altitude at some locations by up to 500 m,
resulting in changes in the sky obscured by the horizon of up to 15%. The
geographical distribution of UV irradiance and actinic flux shows that with
larger pixel size, uncertainties in UV irradiance and actinic flux
determination of up to 100% are possible. These large changes in incident
irradiance and actinic flux with changing pixel size are strongly connected
to shading effects. The effect of the DEM pixel size on irradiance and
actinic flux was studied at the six locations, and it was found that
significant increases in irradiance and actinic flux with increasing DEM
pixel size occurred at one valley location at high solar zenith angles in
the Innsbruck area as well as for one steep valley location in the Sonnblick
area. This increase in irradiance and actinic flux with increasing DEM
resolution is most likely to be connected to shading effects affecting the
reflections from the surroundings. |
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