Influence of the Solar Wind on Auroral Absorption Events at Very High Geomagnetic Latitudes
1986 Volume 38 Issue 11 Pages 1109-1114
Details
1986 Volume 38 Issue 11 Pages 1109-1114
We investigate numerous unusual appearances of auroral absorption events measured by riometers located at the center of the Southern polar cap. We have shown that such nighttime (in MLT) events take place during the expansion phase of magnetospheric substorms and are closely associated with both high velocity (V≥600km s-1) solar wind fluxes and strong negative Bz values. The polar ionosphere behaviour is also studied. A model for the propagation of the westward travelling surge was recently developed by ROTHWELL et al. (1984). This model seems to be an appropriate tool for describing the events if one takes into account the solar wind velocity.
We believe that the daytime polar cap auroral absorption events which are not as numerous and intense as their nighttime counterparts have a different origin.
