Statistical Analysis of Substorm Events Using the WINDMI Model

The SuperMAG magnetic index called the SML index characterizes variations in the Earth's magnetic field due to significant external geomagnetic activities resulting from substorms. This index serves as a crucial parameter for detecting substorm onsets, as utilized by several authors ([1]–[5]). The outputs from the low-order physics-based model WINDMI can also be employed to analyze substorm onsets. In this paper, we evaluate the outputs from the model against the aforementioned techniques to derive criteria for the field-aligned current (FAC) <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</tex> <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> and its time derivative, both of which are outputs from the model. These criteria hold potential significance in predicting substorm onsets from solar wind data.