The results of simultaneous investigations into variations of the optical aerosol extinction coefficients, atmospheric electric field strength, and UV flux (280-320 nm) in June 2004 near Tomsk are considered. The effect of the antiphase dynamics of the aerosol extinction coefficient at 0.45 mkm and the electric field strength, observed for 10 days, is discussed. It is shown that this effect coincides in time with minimum of sunspots. A physical hypothesis taking into account all the observed experimental facts is proposed to explain this phenomenon. The temporal dynamics of the coefficient a(0.45) and the UV flux in June 1-24 is analyzed. The presence of an in-phase low-frequency oscillation component with close periods in the both cases suggests the existence of a weak, but still noticeable influence of the solar UV radiation on optical characteristics of aerosol in the lower troposphere.