1:45 PM - 2:05 PM
[PEM14-24] Geomagnetic Phenomena near the AUTUMNX Magnetic Array in Québec, Canada
Keywords:geomagnetism, magnetometer, data inversion, GIC, substorm, magnetic conjugacy
The dense coverage of the Eastern Hudson Bay part of AUTUMNX allows magnetic inversion studies to be done well. Here we use techniques based on forward modelling to analyze cross meridian and regional currents. In addition to substorms, some of small total current, we find that steady convection is common. The currents in the March 17, 2015 storm attained 3 MA. A new finding relevant to space weather is that impulsive events are common. The Hydro-Québec utility measures harmonic distortion in the grid, and we find a close correlation with impulsive events. Our first detection of a pulse subsequently found to cause GIC in the Hydro-Québec network was on February 2, 2017 (link given above). In approximately 50 other cases, we have verified that GIC pulses initially detected in the grid had associated magnetic impulses. These are sometimes associated with substorms, but those which are not often show direct correlation with solar wind changes.
The AUTUMNX array has distinct advantages for ground magnetic studies in which high data rate, coverage of a large region, at least one closely spaced meridian chain, and conjugacy to geosyncronous satellites are important. We have also compared magnetic data with that from nearby GPS stations to show colocation of the auroral electrojets with scintillation during a storm. To these we currently add proximity to the major Hydro-Québec power grid servicing eastern North America for studies on space weather effects. There is further the potential for interhemispheric studies both on the conjugate magnetic footpoints in Antarctica at latitudes interesting for substorm studies, and along the meridian overlapping with Asia for day/night studies.
AUTUMNX was built with support from the GO Canada programme of the Canadian Space Agency, which now supports its operation.