North-south asymmetry of the substorm intensity depending on the IMF B Y -component

Abstract

The dependence of maximum variations of H-component negative bays at magnetic conjugate stations on a sign of the IMF B Y -component during the substorms of small and moderate intensity with |ΔH|max < 750 nT developed at B Z < 0 and |B Z / B Y | < 1 has been studied. By data from Kotzebue (Φ = 64.5°; Λ = 249.7°) and Macquarie Isl. (Φ = −64.5°; Λ = 247.8°) observatories in the eastern hemisphere and Leirvogur (Φ = 65.3°; Λ = 68.2°) and Syowa (Φ = −66.1°; Λ = 71.0°) stations in the western hemisphere it is shown that at B Y < 0 the absolute values of negative bays |ΔH|max are greater in the southern hemisphere and at B Y > 0, on the contrary, in the northern hemisphere.