Study of Magnetic Storm Current Systems by the Application of Wavelet Analysis to Ground-Based Magnetograms

摘要

Ground-based magnetograms are used to measure the intensity of magnetic storms, yet the relative contributions of the current systems involved have been debated for decades. Wavelet analysis is a technique to analyze signals with complex content and is well suited to the analysis of time-series data. I applied wavelet analysis to ground magnetograms to extract information about magnetic storms current systems. The analysis showed three components at low- and mid-latitudes: 3-6 hours, 12-25 hours, and >30 hours, with each most likely associated with different current systems. Wavelet analysis also enabled the separation of directly driven and unloading components in high- latitude magnetic data. This allowed a comparison of low- and high-latitude substorm measurements to calculate the confignration of the substorm current wedge. Reasonable wedge configurations were found that matched the magnetic measurements. (135 pages).