Analysis of Large Geomagnetically Induced Currents During the 7–8 September 2017 Storm: Geoelectric Field Mapping

Abstract

Geomagnetically induced currents (GICs) are intense, low-frequency currents induced in large conductive systems like power lines and pipelines, during space weather events (e.g., Lakhina et al., 2021). GICs, depending on the solar wind and the Earth's electrical conductivity structure, were analyzed extensively for many years (e.g.,

Multi‐Site Transfer Function Approach for Real‐Time Modeling of the Ground Electric Field Induced by Laterally‐Nonuniform Ionospheric Source

“…Note that coefficients a i and b i are time‐independent, but depend on pipeline physical parameters. In case when the conductivity distribution and the source are both laterally uniform, Equation degenerates to $$$GIC(\mathbf{r},t)=a(\mathbf{r}){E}_{x}(\mathbf{r},t)+b(\mathbf{r}){E}_{y}(\mathbf{r},t).$$$ The Equation has been used in many studies (e.g., Pulkkinen et al., 2001; Trichtchenko and Boteler, 2002; Wawrzaszek et al., 2023), but due to the obvious lateral nonuniformity of the conductivity distribution and the source in the region under investigation, we use Equation to calculate GIC.…”

“…The Equation 13 has been used in many studies (e.g., Pulkkinen et al, 2001;Trichtchenko and Boteler, 2002;Wawrzaszek et al, 2023), but due to the obvious lateral nonuniformity of the conductivity distribution and the source in the region under investigation, we use Equation 12 to calculate GIC.…”

Review of Geomagnetically Induced Current Proxies in Mid-Latitude European Countries

“…The geomagnetic field is measured by stations located at a wide range of latitudes (also at mid-latitudes of European countries) with 1 s, 10 s, or 1 min resolution. It is worth mentioning that the spatial distribution of stations is non-uniform and sparse for mid-latitudes, which, next to the time resolution of the measurements, has a direct influence on the possibility of application of some methods (e.g., [60]).…”

“…As described above, GIC modeling can be validated and compared with direct GIC measurements made along electric power grids and oil and gas pipelines. The most-popular ones are the GIC recordings in the Finnish natural gas pipeline near Mäntsälä presented in the upper panel of Figure 1, during the famous September 2017 geomagnetic storm (e.g., [60]). It is located at subauroral latitudes (57.9 [82].…”

“…The temporal variability of the electric field was calculated using two methods: (1) that proposed by Viljanen and Pirjola [101] and (2) the one-dimensional layered conductivity Earth model (e.g., Boteler et al [72]). The second method was performed using the conductivity values of the lithospheric layers determined for Poland [74] at individual depths [60,102]. Figure 2 presents the sample of the computed local geoelectric field E and its components, E X and E y [60].…”