Pc1–2 auroral pulsations

Abstract

AbstractBy observations at Lovozero station (64.3 N, 114.3 E CGM coordinates), we have investigated two events of auroral pulsations of Pc1–2 type with periods in the range 2.5–7 s accompanied by similar geomagnetic pulsations. Luminous variations in different parts of the sky were found by photometric measurements of the frames of all‐sky camera, which was operated at the rate of one frame per second. The pulsations under study are associated with the diffuse aurora. For the event with 7 s period, a phase relationship between auroral and magnetic pulsations is as follows: the luminosity bursts are coincident with positive half periods in the Z component and negative ones in the D component, while positive peaks in the H component lag behind the luminous peaks by about π/2. For the event with 2.5 s period, this relationship appears different. Within one of 10‐min intervals, Pc2 pulsations observed in both magnetic field and aurora were superposed by regular Pc4 pulsations of 1‐min period. For these, the luminosity bursts corresponded to negative half periods in the Z component. A connection between auroral and magnetic pulsations is discussed.