The effects of geomagnetic storms on the Earth are: effects on communication systems, effects on navigation systems, and effects on power systems.
The impact on communication systems: geomagnetic storms cause drastic changes in the geomagnetic field, which affects the propagation of communication signals. During a magnetic storm, shortwave communications may be severely interfered with or even completely disrupted.
Effects on navigation systems: The effects of geomagnetic storms on the Earth's magnetic field are transmitted to the Earth's navigation systems, such as compasses and magnetic compasses. During a magnetic storm, these navigation devices may be misread or disabled.
Effects on power systems: Electromagnetic radiation from earth's magnetic storms may produce induced currents on power system transmission lines, which can lead to damage to power equipment. In addition, magnetic storms may cause voltage fluctuations in the power grid, affecting power supply.
Alert Levels and Research Progress:
For the delineation of the alert level of geomagnetic storms, it is usually characterized by the Kp index. A geomagnetic Kp = 9 is considered a strong geomagnetic storm, and a red alert is issued; a geomagnetic Kp > 7 is considered a moderate geomagnetic storm, and an orange alert is issued; a geomagnetic Kp > 5 is considered a weak geomagnetic storm, and a yellow alert is issued. In a solar activity week, weak geomagnetic storms occur about 2,000 times, moderate geomagnetic storms about 300 times, and strong geomagnetic storms only a few times.
In 2016, a research team led by Special Assistant Professor Oyuki Shioda of the Institute for Space-Earth Environmental Research at Nagoya University and Professor Ryumo Kataoka of the National Institute of Polar Research at Nagoya University in Japan developed a data simulation system that can reproduce the entire process of the high-speed plasma cloud released during solar eruptive activity and the strong magnetic field impacting the Earth's magnetosphere, with a higher degree of accuracy than previous systems. The results of this research are expected to improve the accuracy of predicting the process and scale of magnetic storm formation.
Reference: Baidu Encyclopedia - Geomagnetic storms