A statistical study of Bills (SMCs), isolatedsubstorms, and individual sawtooth injections

摘要

There are many similarities and differences in the solar wind drivers during threeof the main modes of convection in the magnetosphere (isolated substorms, globalsawtooth oscillations, and steady magnetospheric convection (SMC) events, which weterm here balanced reconnection intervals (BRI)). Thus, this investigation utilizesstatistical analysis to Compare the solar wind and interplanetary magnetic field (IMF)drivers and their steadiness (standard deviation divided by the mean) during these threedifferent event types. By including the steadiness of the drivers, the importance ofmagnitude, sign, and stability of the drivers for the different modes can be investigated. Aseries of histograms with each mode plotted over top of 6 years of background is usedto measure the deviation of the mode drivers from the nominal data, and also allowsfor a comparison between each event type. We found that the magnitude and directionof 13, are the dominate driver for substorms, while BRIs and sawteeth require bothmagnitude and steadiness of certain drivers to occur. Both BRIs and sawteeth show similarsteadiness in their drivers, while the magnitude of the drivers is much stronger for thesawtooth oscillations. Also included in this study are the substorms that initiate BRIs. Thesolar wind and IMF drivers for the initiating substorms are similar to drivers for BRIs;thus initiating substorms of BRIs are different from isolated substorms and may play a rolein preconditioning the magnetosphere for BRIs.