LATITUDINAL DEPENDENCE OF THE GEOMAGNETIC RESPONSE TO SOLAR WIND PRESSURE VARIATIONS DURING THE EARTH'S PASSAGE OF THE JULY 15-16, 2000 CORONAL EJECTA

摘要

In this work we present the analysis of the geomagnetic field fluctuations observed at different ground stations (approximately along a geomagnetic meridian) during the passage at the Earth's orbit of the tail of the July 15-16, 2000 coronal ejecta. The time interval of interest is characterized by northward interplanetary magnetic field conditions and several changes of the solar wind dynamic pressure. On the ground, at geomagnetic latitudes between 36°and 64° a close correspondence between the horizontal geomagnetic field component and the solar wind pressure variations is observed around local noon, while no correspondence at all emerges during the local morning. The amplitude of the response around local noon shows a monotonic increase with the increasing latitude.