Extensive reduction of surface UV radiation since 1750 in world's populated regions 1Department of Geosciences, University of Oslo, P.B. 1022 Blindern, 0315 Oslo, Norway
2Center for International Climate and Environmental Research – Oslo (CICERO), P.B. 1129 Blindern, 0318 Oslo, Norway
3Norwegian Institute for Air Research, P.B. 100, 2027 Kjeller, Norway
Received: 09 March 2009 – Published in Atmos. Chem. Phys. Discuss.: 30 April 2009 Abstract. Human activity influences a wide range of components that affect the surface
UV radiation levels, among them ozone at high latitudes. We calculate the
effect of human-induced changes in the surface erythemally weighted
ultra-violet radiation (UV-E) since 1750. We compare results from a
radiative transfer model to surface UV-E radiation for year 2000 derived by
satellite observations (from Total Ozone Mapping Spectroradiometer) and to
ground based measurements at 14 sites. The model correlates well with the
observations; the correlation coefficients are 0.97 and 0.98 for satellite
and ground based measurements, respectively. In addition to the effect of
changes in ozone, we also investigate the effect of changes in SO2,
NO2, the direct and indirect effects of aerosols, albedo changes and
aviation-induced contrails and cirrus. The results show an increase of
surface UV-E in polar regions, most strongly in the Southern Hemisphere.
Furthermore, our study also shows an extensive surface UV-E reduction over
most land areas; a reduction up to 20% since 1750 is found in some
industrialized regions. This reduction in UV-E over the industrial period is
particularly large in highly populated regions.
Revised: 21 September 2009 – Accepted: 28 September 2009 – Published: 19 October 2009
Citation: Kvalevåg, M. M., Myhre, G., and Lund Myhre, C. E.: Extensive reduction of surface UV radiation since 1750 in world's populated regions, Atmos. Chem. Phys., 9, 7737-7751, doi:10.5194/acp-9-7737-2009, 2009.