Fig. 6

Representation of the method used to determine the ideal storm detection parameters for a given method. In this case when using the MODWT, a _MODWT is the amplitude a peak in the squared MODWT needs to exceed to trigger a potential detection, and p _MODWT is the period it needs to exceed this amplitude to be a proper detection. The test “detector” was tested on the geomagnetic data using each pair of values within a certain range (\(0.00 < a_{\mathrm{MODWT}} \le 0.01\,{\hbox {nT}}^2\) and \(20 < p_{\mathrm{MODWT}} \le 90\) s), and the numbers of correct detections and false positives were recorded. The best parameters were those that had the highest percentage of correct detections out of the total possible (left) and the correspondingly highest percentage of correct detections out of all detections made, including false positives (right)