Temporal changes in the north-south asymmetry of polarized light of Jupiter may be associated with the comet SL9 visit to the Jovian system

Polarimetric observations of Jupiter at blue wavelengths were taken during the comet SL9 collision with the planet and compared with seven other observations made during the period from 1981 to 1995. The data show temporal variations in the north-south asymmetry of polarization of high latitudes. Before 1993–1994 the polarization degree near the north limb is greater than that for the symmetrical regions near the south limb. In the July 1994 data the difference between the polarization degrees at north and south vanished. The observations of 1995 show the degree of polarization at south latitudes to be greater than that at the same north latitudes. These changes may be related to the increase of dust abundance in the magnetosphere and stratosphere of Jupiter owing to the visit of comet SL9 to the Jovian system. However, correlation between temporal variations of the polarization asymmetry and the magnetic solar cycle cannot be ruled out.