Quadrantids 2008 and 2009: Detection of Dust in the Atmosphere by Polarization Twilight Sky Measurements

The paper contains the results of the polarization measurements of twilight sky background during the wintertime including the epoch of Quadrantids activity in January 2008 and 2009 in Crimea (Ukraine). Analysis of the twilight sky polarization behavior had shown the barely detectable depolarization effect at the scattering altitudes above 90 km right after the Quadrantids maximum. This effect can be related with the meteoric dust in the upper atmosphere of the Earth.