Development of substorm bulges during storms of different interplanetary origins

摘要

Different solar wind structures are observed: magnetic clouds (MC), recurrent streams (RS), and regions of their interaction with undisturbed solar wind (Sheath and CIR). Three of these structures, Sheath, CIR, MC, are the sources of geomagnetic storms. We have searched for distinctions in the development of substorm bulges occurring during geomagnetic storms connected with the MC, Sheath and CIR. Solar wind parameters were taken from the Wind spacecraft and the auroral bulge parameters were obtained from the Ultra Violet Imager onboard Polar spacecraft. We determined the dimensions of the auroral bulges, the poleward aurora propagation, and the onset latitude of auroral bulges. It is shown that auroral bulges "geometry" is different for the examined types of storms. In consequence, the ratio between longitudinal and latitudinal sizes is also different.