Spectral investigations of the solar radiation during the total solar eclipse on March 29, 2006

Abstract

We present results from examination of the dynamics and spectral distribution of the solar radiation reaching the Earth's surface during the total solar eclipse on March 29, 2006. The solar spectra were recorded using a multichannel spectrometer OCEAN USB2000 in 2048 spectral channels in the spectral range 350–1000 nm at a spectral resolution (halfwidth) of 1.5 nm. The spectral measurements were carried out between the 1st and 2nd and the 3rd and 4th contacts of the total solar eclipse from an observation point situated on the Mediterranean Sea coast, Antalya region, Turkey. The spectral data were evaluated using statistical methods such as the Student's t-criterion and others. The changes in dynamics of incident solar radiation intensity before and after eclipse totality were found to correlate ( R≈0.998) with the changes during the total Sun's eclipse on August 11, 1999, observed from an observation post on the line of totality situated on the Black Sea coast on Bulgarian territory. The changes in solar radiation measured before and after totality, within the absorption bands of water and oxygen, as well as along the spectra envelope, show statistically significant differences, which point to an unstable terrestrial atmosphere. Images from concurrent videometric observations proved that fine cloudy structures have appeared after totality in front of the solar disk.