Effects of total solar eclipse of 29 March 2006 on surface radiation

Abstract

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 Planck's law.

The effects of a solar eclipse on photo-oxidants in different areas of China

“…This limb darkening is spectrally dependent because radiation from the limb of the solar disk is less intense than that from the centre. Thus the spectral composition of the irradiance of the sun changes during the eclipse (Emde and Mayer, 2007;Kazantzidis et al, 2007;Koepke et al, 2001).…”

“…In Kazantzidis (2007), a radiative transfer model was used for computation of a correction for the total ozone measurements due to the limb darkening. This correction was found to be too small (less than 0.01 %) to explain the large decrease in total ozone column.…”

“…Temperature, solar irradiance, relative humidity, wind and cloudiness within the surface layer are among the most common meteorological parameters explored by previous studies of solar eclipses (Fernandez et al, 1993(Fernandez et al, , 1996Hanna, 2000;Psiloglou and Kambezidis, 2007;Emde and Mayer, 2007;Kazadzis et al, 2007). The drop in surface temperature during a solar eclipse is of broad interest and becomes noticeable when the sun is about half covered (Anderson, 1999).…”

Influence of solar eclipse on seawater

“…Zerefos et al [24] pointed out that the eclipse-induced cooling of the ozone layer in the stratosphere is the main source of gravity waves propagating both upwards and downwards. Measurements of total column of ozone [9] using Brever Spectrophotometers have revealed that there was a reduction of 30-40 DU total ozone on the day of eclipse, 29 March 2006, than the day before at Athens. Such a reduction in surface O 3 may be due to decreased efficiency of the photochemical O 3 formation [13].…”

“…Several measurements of solar radiation were carried out since 1960; recent works [7,8] focussed on the study of eclipse-induced changes in the spectral solar irradiance at the earth's surface, the effect of multiple scattering on sky brightness, and the wavelength dependence of the limb darkening effect etc.. The radiations in shorter wavelengths (350 nm) are generally influenced more by the eclipse, and at large eclipse percentages (> 85%), it slowly decreases as the eclipse approaches its maximum [9,10] compared to that of the longer wavelengths. Hence, one can expect shorter wavelength radiations during partial eclipse, which is less studied.…”