Monthly Archives: March 2014

Feb 27, 2014 geomagnetic storm and aurora

Solar Cycle 24 has been somewhat scarce in terms of mid-latitude aurora as there have been few very complex and active sunspots. On February 25th sunspot group AR 1990, returning for its third rotation (!), produced a strong X4.9 flare. It caused a fast full-halo coronal mass ejection, but as the sunspot was still near […]