Auroral structure over the Kola Peninsula and the X-ray oval measured on February 9, 1997, onboard the POLAR satellite

A comparative analysis of the structures of aurorae detected by a TV camera over the Kola Peninsula and an oval of the X-rays recorded with a PIXIE in strument on board the POLAR satellite during the extended magnetic perturba tion of February 9, 1997, is carried out in this work. It has been shown th at auroral active forms can be divided into three groups: the auroral inten sifications associated with a marked increase in X-rays, active aurorae not accompanied by X-rays, and active and large-scale auroral forms accompanie d by slight and short-term bursts of X-rays, The conclusion has been made t hat the difference in the energy spectrum of auroral electrons reflects dif ferent structures of the electric fields and, correspondingly, the characte r of the instability activating the substorms.