Institution: | 1Institute of Ionospheric and Space Research, National Observatory of Athens, 15236 Penteli, Greece 2Solar-Terrestrial Environment Laboratory, Nagoya University, Toyokawa 442, Japan 3Max-Planck-Institut für Aeronomie, 37191 Katlenburg-Lindau, Germany 4Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 5Demokritos University of Thrace, 37100 Xanthi, Greece |
Abstract: | Following a long period of consensus on the storm-substorm relationship, a dispute on this topic has emerged in recent years. The importance of substorms for the buildup of the terrestrial ring current, which is the major element of magnetic storms, has been questioned in several studies. This paper is an effort to assess the “fine structure” of the storm-substorm relationship, by investigating the correlation between the changes in Dst and the substorm-associated O+ enhancements in the inner magnetosphere during the storm main phase. For this purpose we use energetic ion measurements from the Magnetospheric Ion Composition Spectrometer (MICS) on board the Combined Release and Radiation Effects Satellite (CRRES), and the newly produced high-resolution (5-min) Dst index for the intense storm of June 5, 1991. Substorm signatures from both MICS measurements and ground magnetometers correlate well with changes in the Dst decrease rate. This implies a significant influence of substorm occurrence on storm dynamics. |