太阳耀斑爆发，可能引发中等或更强地磁暴

Core Viewpoint - A medium-strength solar flare of M8.1 occurred on December 7, 2025, from solar activity region 14299, but it did not affect China as it happened during nighttime [1][2]. Group 1: Solar Activity - The solar flare was accompanied by a coronal mass ejection (CME), which was relatively weak and emitted a small amount of material [2][3]. - The material from the CME is expected to reach Earth on December 9, potentially causing geomagnetic storms with moderate to strong intensity [3]. - Solar activity region 14299 has a complex β-δ magnetic field structure and covers an area of 268 microhemispheres (µh) [3]. Group 2: Future Predictions - The solar activity level is expected to remain moderate over the next three days, with the possibility of M-class flares [5]. - Geomagnetic activity is predicted to be calm to minor on December 8, but geomagnetic storms may occur on December 9-10 due to the CME [5]. - Ionospheric weather is expected to be mostly calm, with potential disturbances on December 9-10 [6]. Group 3: Recent Observations - In the past 24 hours, solar activity was low, with no M-class flares observed, and a new activity region 14303 was identified [8]. - The largest current activity region, 14294, has an area of 800 µh and a complex β-γ-δ magnetic field structure, indicating potential for future eruptions [8]. - Geomagnetic activity was active for three hours, while solar wind speed decreased from 630 km/s to around 440 km/s [8].