Pulses in Solar Wind Pressure and the Occurrence of Intense Geomagnetically Induced Currents

The occurrence of geomagnetically induced currents (GICs) in Northwest Russia associated with pulses in the dynamic solar wind pressure is investigated. A detailed analysis of the complex space weather event of November 3–4, 2021, is performed using data from the OMNI database and the IMAGE and SuperMAG magnetometer networks. Types and parameters of the solar wind and geomagnetic activity are compared to the occurrence of intense GICs using direct measurements of the current in the solid-earthed neutral line of autotransformers on the Karelian–Kola power line (Vykhodnoy, Loukhi, and Kondopoga) and the gas pipeline in the Mäntsälä area (Southern Finland). The complex space weather event is divided into three cases observed in the midnight, morning, and daytime sectors. Each case is associated with a spike in the dynamic solar wind pressure (∼20–30 nPa). It is shown that the GICs in the midnight and morning sectors were caused by intensification and expansion of the westward electrojet during substorms. In the daytime and early evening sectors, the source was sharp intensifications of the eastward electrojet that were associated with the development of supersubstorm and intense substorms on the night side. In the morning and daytime MLT sectors, Pi3 pulsations were observed during and after the recovery phase of the substorms, which also caused GICs that were less intense.