Space Weather Effects on Critical Infrastructure

Gas pipelines, transmission lines, overhead wires, transformers, GNSS navigation, and telecommunication systems are part of critical infrastructure. Industry, transportation, service operations, farming, and everyday life highly depend on this infrastructure. However, these systems are very sensitive to solar activity. Therefore, all activities above are vulnerable and defenseless against the catastrophic changes in Earth's cosmic environment. The Solar System is dominated by the influence of our star. A small fraction of the energy produced in the core of our star turns into a magnetic field and emits the constant high-velocity flow, the solar wind. Solar magnetic activity produces radiation and ejects matter from the upper atmosphere of our star. The magnetic field of the solar wind interacts with the planetary magnetic fields and atmospheres. These phenomena, called Space Weather have a serious influence on the radiation environment of Earth where telecommunication, Global Navigation Satellite System, meteorological, and other purpose satellites are located. The conductivity and transparency of the higher partly ionized atmospheric layer, the ionosphere also depend on solar radiation and activity. This fact makes the navigation and communication systems dependent on solar activity. Finally, the solar magnetic activity creates magnetic variations in the terrestrial magnetic field and induces currents in gas pipelines, transmission lines, overhead wires, and transformers. In this short briefing, we introduce the solar activity phenomena, and their influence on our planet's cosmic neighborhood and provide a detailed description of the Space Weather effects on critical infrastructure. We describe the Hungarian national and global space weather forecast centers and capabilities. Finally, we share some guidelines on how to prepare for extreme space weather events.Comment: submitted paper to a conference proceedings of the 4th International Conference on Central European Critical Infrastructure Protection held from November 17 to 18, 2022 in Budapest, Hungary, 25 pages, 8 figures, 2 table

3D pressure-corrected ballistic extrapolation of solar wind speed in the inner heliosphere

Solar wind parameters at different locations in the inner heliosphere can be estimated using various solar wind extrapolation methods. The simple ballistic method extrapolates solar wind parameters from the point of measurement to a chosen heliospheric position by assuming that major solar wind structures are persistent and arrive relatively unaltered to the target position. The method considers the rotation period of the Sun while assuming a constant solar wind speed during radial propagation. We improve the simple ballistic model by considering the interaction between the slow and the fast solar wind with a pressure correction during the propagation. Instead of extrapolating from the position of a single spacecraft, we apply this pressure-corrected ballistic method to 2D speed maps of the solar source surface available from solar coronal models to determine the solar wind speed in the inner heliosphere in 3D, between latitudes of ±50°. We also take into account the effects of the solar differential rotation in our model. Our method is simple and fast, and it can be applied to different source surface datasets. The results of our model are validated with in situ data from the ACE spacecraft. We find that the pressure-corrected ballistic method can give accurate predictions of the solar wind in 3D

Orientation of the stream interface in CIRs

Corotating Interaction Regions (CIRs) are complex structures in the Heliosphere that arise from the interaction of fast and slow solar wind streams. The interface between fast and slow solar wind is called the stream interface, which often has considerable north-south tilt. We apply a sliding window correlation method on multi-spacecraft data in order to obtain the time delay between the spacecraft. Using these time delays and in-situ solar wind velocity measurements, we can shift the positions of two spacecraft, and, together with the position of the reference spacecraft, we can reconstruct the spatial orientation of the stream interface. We examined four CIRs from two different solar sources at the beginning of 2007 using ACE, WIND, and STEREO-A spacecraft data. The gradually increasing distance between STEREO-A and the other spacecraft provides an opportunity to determine the effects of spacecraft separation on the quality of the results. In three out of the four events, the determined planes generally follow the Parker spiral in the ecliptic, their off-ecliptic tilt is determined by the position of the source of the high-speed stream. For the fourth event, STEREO-A was probably too far away for this method to be successfully applied