Analysis of the October 3-7 2000 GEM storm with the WINDMI

dimensional physics model WINDMI is used to analyze the October 3–7, 2000 geomagnetic storm using solar wind input data from the ACE satellite. This period was chosen because it contains an extended interval of well-defined and quasi-periodic auroral activations called sawtooth oscillations, a phenomena whose relationship to substorm processes and to upstream solar wind drivers is still under debate. The question of whether multiple sawtooth oscillations are triggered by periodic upstream solar wind features or by internal magnetospheric processes is addressed. The model predicts both the occurrence of 8 auroral activations identified as sawtooth events during the 24 hour period on the 4th of October, in agreement with the measured AL index, and also an earlier multiple sawtooth interval on the 3rd of October, in agreement with the measured AL index. These intervals occur during steady but moderate solar wind IMF Bz values and the periodicity of the sawtooth events was not directly related to any periodic features in the upstream solar wind. The model also predicts the geomagnetic Dst index through the main and recovery phase of the storm