Paper#: 91
Poster #: 24
Session Name: Poster Session 1
Room: East Ballroom
Day: Tuesday
Time: 10:10 a.m.-Noon
Abstract Title: Modeling of Substorm Activity by the Discreet Model with Magnetosphere-Ionosphere Feedback
PresentSurname: Kozelov, B.V.
All Authors: B.V. Kozelov, T.V. Kozelova
Abstract : Observational studies of magnetospheric activity suggest that magnetosphere-ionosphere coupling plays a critical role in the physical processes leading up to substorm onset. The cellular model as an analogy of the dynamic magnetosphere-ionosphere system related with the substorm activity is presented. The model contains the positive feedback arising between magnetospheric and ionospheric parts of each magnetic field tube. Dynamics of the model for constant input parameters and for driving by z-component of Interplanetary Magnetic Field is discussed. It was found that when the model with feedback is driving by Bz IMF, it demonstrates features observed in the magnetosphere-ionosphere system: the probability distribution of the transient power for the moments, when the feedback is activated, has a characteristic maximum at large values and power law segment at small values. This distribution looks like the one obtained in (Lui et al., 2000) for auroral blobs during substorms. Similar distribution for the moments, when in all cells of the system feedback is not activated, has no maximum. Also our model calculation have shown that probability distribution of avalanche power in model at the self-organized critical (SOC) state has no power law form. Therefore the results of (Lui et al., 2000) can not be used as an evidence of the SOC state in the magnetosphere and may be explained by magnetosphere-ionosphere feedback with driving by solar wind. The work was supported by grants of RFBR-01-05-64827 and INTAS-99-0078.