Map of the Italian power grid
The Italian power grid consists of transmission lines operating at 380-400 kV (red), and 220-275 kV (green) plus a high voltage DC transmission line running under the sea to the island of Sardinia (pink). The four dots indicate the geomagnetic observatories for which data was used in the highlighted article. Future assessments of space weather risks should include assessments of whether coastal effects can enhance geoelectric fields induced by space weather, and thus affect transmission lines near coasts. The map is derived from the 2018 map of the European Network of Transmission System Operators. Credit: Tozzi et al. [2019], Figure 1
Source: Space Weather

Geomagnetically induced currents (GIC) driven by space weather have the potential to disrupt national power grids the world over. Tozzi et al. [2019] use the “GIC index” developed by Marshall et al. [2011] to make a preliminary assessment of the risk from space-weather GIC to the Italian power grid. This index is a convenient tool for initial GIC risk assessment as it is derived from geomagnetic measurements readily-available from ground-based observatories, in this case from observatories in northern and central Italy and on the Mediterranean island of Lampedusa.

The authors show that significant GIC can flow in the Italian power grid during space weather events, such as large sudden commencements and sharp changes in the strength of the ring current. They thus make the case for deeper assessment of GIC risks, for example, to take account of ground conductivity and coastal effects. They also note that a wider census of power grid failures is needed to better calibrate how the GIC index can be used for assessment of the risk that space weather poses to power grids in countries at lower magnetic latitudes.

Citation: Tozzi, R., De Michelis, P., Coco, I., & Giannattasio, F. [2019]. A preliminary risk assessment of geomagnetically induced currents over the Italian territory. Space Weather, 17.

—Michael A. Hapgood, Editor, Space Weather

Text © 2019. The authors. CC BY-NC-ND 3.0
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