美国发布警报

Core Viewpoint - The article discusses the severe geomagnetic storm and solar radiation storm currently affecting Earth's space environment, with impacts expected to last until the 21st [1][2]. Group 1: Geomagnetic and Solar Radiation Storms - The National Oceanic and Atmospheric Administration (NOAA) issued a warning about a strong geomagnetic storm and severe solar radiation storm, triggered by a solar flare on the 18th, which resulted in an S4 level solar radiation storm [1][2]. - The geomagnetic storm reached G4 level (severe) on two occasions, first on the 19th and again on the 20th, marking the strongest geomagnetic activity since October 2003 [2]. Group 2: Impacts on Infrastructure and Communication - High-latitude regions may experience voltage fluctuations in power systems, with some power grids facing operational instability risks due to the strong geomagnetic storm [2]. - Satellites may encounter attitude anomalies and increased atmospheric drag, while high-frequency radio communications in high-latitude areas could experience attenuation or interruptions [2]. - The S4 level solar radiation storm poses increased radiation exposure risks for astronauts and polar flight personnel, as well as heightened risks for geostationary satellites and space launch systems [2].