MID-LATITUDE AURORA IN SOLAR CYCLES 23–24 FROM OBSERVATIONS IN THE SOUTH OF EASTERN SIBERIA

Abstract

The paper presents observations of mid-latitude aurora (MA) in the south of Eastern Siberia in solar cycles 23–24. Spectral composition and dominant emissions of MA, daily distribution of MA detection probability, dependence on the level of geomagnetic activity, and classification according to types of aurora are discussed. A close relationship is shown between the intensity of dominant emission at 630.0 nm and the Dst index during magnetic storms (MSs). It is pointed out that the most intense MA are recorded during MS main phases. The MA detected on November 20, 2003 can enlarge the list of great aurora. For the severe MSs (Dstmin< –200 nT) of March 24, 1991, April 6, 2000, October 30 and November 20, 2003, March 17, 2015, the observed dynamics of 557.7 and 630.0 nm auroral emissions is presented. Mechanisms of emission excitation during geomagnetic storms and a possible connection with magnetospheric structures are discussed.