Magnetosphere Distortions During the 'Satellite Killer' Storm of February 3-4, 2022, as Derived From a Hybrid Empirical Model and Archived Data Mining

N. A. Tsyganenko, V. A. Andreeva, M. I. Sitnov, G. K. Stephens


A pair of relatively mild geomagnetic storms of February 3-4, 2022, resulted in the loss of 38 Starlink satellites. In this work we reconstruct a sequence of magnetospheric configurations during that event, based on the largest ever archive of historical data, a new magnetic field model, and the nearest-neighbor method of mining the solar wind, magnetosphere, and ground activity data. The model is constructed as a combination of main modular framework, explicitly representing magnetic effects of principal current systems, and a high-resolution superstructure, based on expanding the field of equatorial currents into a sum of quasi-orthogonal harmonics, whose purpose is to correct residual inaccuracies of the modular component. In addition, the variable penetration of the interplanetary magnetic field (IMF) into the magnetosphere is taken into account in the form of a potential field, parameterized by the observed IMF components. Despite relatively modest intensity of the event in terms of Sym-H peak values, surprisingly strong transient distortions of the global magnetic field are found. Whereas under quiet pre-storm conditions the midnight segment of synchronous orbit and the dayside cusps mapped, respectively, to 67 and 77 deg of corrected latitude, at the peak of the storm their footpoints shifted equatorward to as low as 63 deg and 67-68 deg, with formation of entangled flux-rope-like structures and magnetic neutral lines at distances R = 12-15 RE on the nightside. At nearly the same time, a deep magnetic depression and, possibly, an island of reversed field polarity forms even closer, in the post-dusk sector of geosynchronous orbit.
JGRA, published December 5, 2022:

This work was supported by the Russian Foundation for Basic Research (RFBR) grant 20-05-00218.