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| Titel |
Effects of urban pollution on UV spectral irradiances |
| VerfasserIn |
R. L. McKenzie, C. Weinreis, P. V. Johnston, B. Liley, H. Shiona, M. Kotkamp, D. Smale, N. Takegawa, Y. Kondo |
| 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 ; 8, no. 18 ; Nr. 8, no. 18 (2008-09-29), S.5683-5697 |
| Datensatznummer |
250006393
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| Publikation (Nr.) |
 copernicus.org/acp-8-5683-2008.pdf |
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| Zusammenfassung |
| Spectral measurements of UV irradiances at Tokyo are compared with
corresponding measurements at a pristine site (Lauder New Zealand) to
identify the causes of the reductions in urban UV irradiances, and to
quantify their effects. Tropospheric extinctions in Tokyo were found to be up
to ~40% greater than at Lauder. Most of these differences can be
explained by differences in cloud and aerosols, but ozone differences are
also important in the summer. Examining spectral signatures of tropospheric
transmission of both sites shows that reductions due to mean NO2 and
SO2 amounts are generally small. However, at times the amount of NO2
can be 10 times higher than the mean amount, and on these days it can
decrease the UVA irradiance up to 40%. If SO2 shows comparable day to day
variability, it would contribute to significant reductions in UVB
irradiances. The results indicate that at Tokyo, interactions between the
larger burden of tropospheric ozone and aerosols also have a significant
effect. These results have important implications for our ability to
accurately retrieve surface UV irradiances at polluted sites from satellites
that use backscattered UV. Supplementary data characterising these boundary
layer effects are probably needed. |
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