Effects of total solar eclipse of 29 March 2006 on surface radiation S. Kazadzis1, A. Bais1, M. Blumthaler2, A. Webb3, N. Kouremeti1, R. Kift3, B. Schallhart2, and A. Kazantzidis1 1Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Greece 2Division of Biomedical Physics, Innsbruck Medical University, Austria 3School of Earth Atmospheric and Environmental Sciences, University of Manchester, UK
Abstract. Solar irradiance spectral measurements were performed during a total solar
eclipse. The spectral effect of the limb darkening to the global, direct
irradiance and actinic flux measurements was investigated. This effect leads
to wavelength dependent changes in the measured solar spectra showing a much
more pronounced decrease in the radiation at the lower wavelengths.
Radiative transfer model results were used for the computation of a
correction for the total ozone measurements due to the limb darkening. This
correction was found too small to explain the large decrease in total ozone
column derived from the standard Brewer measurements, which is an artifact
in the measured irradiance due to the increasing contribution of diffuse
radiation against the decreasing direct irradiance caused by the eclipse.
Calculations of the Extraterrestrial spectrum and the effective sun's
temperatures, as measured from ground based direct irradiance measurements,
showed an artificial change in the calculations of both quantities due to
the fact that radiation coming from the visible part of the sun during the
eclipse phases differs from the black body radiation described by the
Citation: Kazadzis, S., Bais, A., Blumthaler, M., Webb, A., Kouremeti, N., Kift, R., Schallhart, B., and Kazantzidis, A.: Effects of total solar eclipse of 29 March 2006 on surface radiation, Atmos. Chem. Phys., 7, 5775-5783, doi:10.5194/acp-7-5775-2007, 2007.