ИСТИНА

The ring current development during magnetic storms 21-22.01.2005 and 14-15.12.2006 was studied on the basis of satellite data and theoretical modeling. It was shown that large-scale magnetospheric convection as well as substorm-related injections can not provide the observed magnetic depression at the Earth’s surface during 21-22.01.2005. Comparative analysis of magnetospheric particle fluxes (30-80 keV protons in the near-equatorial region and in the region of isotropic precipitations) measured by low-altitude polar sun-synchronous NOAA satellites (POES 15, 16, 17) shows that the proton fluxes as well as isotropic boundary and maximum precipitation locations were approximately the same during maximum of two storms under consideration. It was shown that ring current development during 21-22.01.2005 magnetic storm was provided by prolonged extremely strong solar wind dynamical impact. Extreme pressure pulse during SSC caused intensive trapped particle radial motion to the lover L-shells and subsequent ring current enhancement similar to that taking place due to particle injection from the tail. Ring current development during 14-15.12.2006 was mostly due to IMF southward turning. Magnetospheric compression during SSC was not too strong to create storm-time ring current.