Quantification of the effect of urbanization on solar dimming
Article first published online: 17 APR 2008
Copyright 2008 by the American Geophysical Union.
Geophysical Research Letters
Volume 35, Issue 8, April 2008
How to Cite
2008), Quantification of the effect of urbanization on solar dimming, Geophys. Res. Lett., 35, L08801, doi:10.1029/2007GL033012., and (
- Issue published online: 17 APR 2008
- Article first published online: 17 APR 2008
- Manuscript Accepted: 10 MAR 2008
- Manuscript Revised: 26 FEB 2008
- Manuscript Received: 18 DEC 2007
- solar dimming;
- atmospheric aerosols
 During the 25-year period (1964–1989), a noticeable decline in surface solar radiation, termed global dimming, over worldwide sites was essentially a local phenomenon associated with human activity as expressed by the sites' population density. Specifically, our findings indicate that solar dimming was observed only over a limited part (∼30%) of the total land area, restricted to highly-populated sites with population density higher than 10 person/km2. Dimming was dominated by anthropogenic aerosol emissions: the decline in surface solar radiation intensified from −0.05 W/m2/yr to −0.32 W/m2/yr, with population density increasing from 10 to 200 person/km2. At sites with population density >200 person/km2, a saturation effect was observed: declining trends were much less pronounced than those over sites with a lower population density. Overall, it is demonstrated that urban areas obtained less solar radiation, compared to rural areas, in the amount of ∼12 W/m2 which is equivalent to about 8%.