Magnetic fields of magnetopause and magnetotail currents on the Earth's surface during magnetic storms

The relationship between magnetic effects generated in the observed D-st variation by currents flowing on the magnetopause (DCF) and in the magnetospheric tail (DT) is analyzed. The analysis is based on data for four medium-intensity magnetic storms. The quantitative characteristics are calculated in a paraboloid model of the magnetospheric magnetic field, which makes it possible to separate the contributions of various sources to the observed magnetic disturbance. It is shown that there is a fairly close relationship between the fields of the currents DCF and DT. These are approximately equal in intensity, are opposite in sign, and vary quite synchronously in time.