“…(
2020) and first construct a 1‐min‐resolution sequence of maps of horizontal‐component geomagnetic field variation. Although our method and the data we use are specialized for the storm of March 1989, our method is similar to that which we use in related explorations of storm‐induced geoelectric fields (e.g., Love, Lucas et al.,
2018; Love, Rigler et al.,
2018; Lucas et al.,
2018,
2020); related methods are used by other investigators in their own studies of geoelectric fields (e.g., Blake et al.,
2016; Cordell et al.,
2021; Marshalko et al.,
2020; Marshall et al.,
2020; Sokolova et al.,
2019; Torta et al.,
2017; Wang et al.,
2020). We assume that the horizontal‐component of geomagnetic field variation B h ( t n | x , y ) at the Earth's surface and at each 1‐min instance in time t n is quasi‐static and that, with the Biot‐Savart law, field variation can be represented across the Earth in terms of an idealized “equivalent” set of overhead electric currents,
(e.g., Panofsky and Phillips, 1962, their Chapter 7–6).…”