Core Viewpoint - A geomagnetic storm triggered by a solar flare reached G5 (extreme) level in South Africa, impacting satellite performance and wireless communication [1] Group 1: Solar Activity - On the 18th, a prolonged X1.9 solar flare caused a coronal mass ejection, leading to charged particles reaching Earth [1] - The geomagnetic storm initially reached G4 (severe) level on the night of the 19th before escalating to G5 (extreme) level early on the 20th [1] Group 2: Geomagnetic Storm Measurement - The Kp index, which measures the intensity of geomagnetic storms, recorded a value of 9 during the G5 storm, indicating a significant disturbance [1] - The Kp index ranges from 0 to 9, with higher values representing stronger geomagnetic storm intensity [1] Group 3: Potential Impacts - The geomagnetic storm can cause severe disturbances in the Earth's magnetosphere, ionosphere, and upper atmosphere [1] - Potential impacts include effects on satellite performance and safety, as well as disruptions to wireless communication [1]

Core Viewpoint - A geomagnetic storm triggered by a solar storm reached G5 (extreme) level in South Africa on January 20, 2023, impacting satellite performance and wireless communication [1] Group 1: Solar Activity - A prolonged X1.9 solar flare on January 18 initiated a coronal mass ejection, leading to charged particles reaching Earth and causing a geomagnetic storm [1] - The geomagnetic storm escalated to G4 (severe) level on the evening of January 19 before reaching G5 (extreme) level early on January 20 [1] Group 2: Geomagnetic Storm Metrics - The Kp index, which measures the intensity of geomagnetic storms, peaked at 9 during the G5 storm, indicating a high level of disturbance in Earth's magnetic field [1] - On January 20 at 6:21 AM, the Earth experienced a Kp value of 6, with solar wind speeds reaching 900 kilometers per second, while the geomagnetic storm intensity in Hermanus was recorded at Kp value 7 [1] Group 3: Effects and Observations - Geomagnetic storms can cause significant disturbances in the Earth's magnetosphere, ionosphere, and upper atmosphere, potentially affecting satellite operations and wireless communications [1] - Residents in parts of South Africa's Western Cape shared photos of auroras on social media, which are more vibrant during stronger geomagnetic storms [1]