Past Events
The last week was exciting in terms of solar activity. Even though there were no significant impacts, there were flares, CMEs and even filament eruptions. On May 28, the images from STEREO A, revealed some regions with magnetic activity which looked promising. Thus once they rotate toward Earth, formation of a sunspot or even an active region was expected. Yet it did not happen as expected. On May 29 at 07.24 UTC, a M1.1 flare has observed at right on the NE limb. This was the first M class flare since October 2017. Later on that day there were C9.3 and C1 flares from the same region at 10.46 and 14.22 UTC respectively. On May 30, the region rotated towards Earth but started to decade before it was numbered as an active region. Thus the Sun has been remaining to seen as a spotless disk for a month. Moreover, 5 CMEs were observed overall throughout the week, yet only one of them were Earth directed which is the one on May 26. The impact was expected as glancing blow on May 30 according to WSA ENLIL model, yet there were no significant effects on that day. The source of some of the CME's were the region caused the M1.1 flare, since it was on the NE limb, those CMEs had no impact on Earth. The filament eruption observed from SDO imagery at SE limb on May 30, 00.00 UTC caused a CME, yet it was not Earth directed either. Lastly, the solar wind speed fluctuated between 270 and 435 km/s. The enhancements were due to the coronal holes. There were no geomagnetic disturbances or enhanced energetic particles either.
Within the last 24 hours, the solar activity was at very low levels. There were no sunspots or active regions. Thus there were no flares. No CMEs were observed through the coronagraph imageries. There are two coronal holes at the both poles. The solar wind speed fluctuated between 370 and 435 km/s. The strength of southward IMF was 3.94 nT at its minimum. The minimum magnetopause standoff distance was 10 Re. The maximum Kp was 2. The geomagnetic indices Dst was -10 nT at its minimum and AE was below 500 nT. The F10.7 radio flux was 71 sfu which is normal during solar minimum.
The solar activity is expected to remain at very low levels in the following days. The region turned from the far side of the Sun is decaying and there are no active regions on the visible disk. Thus no flares are expected. No CME arrivals are expected neither. There are no additional significant coronal holes other than the ones on the poles, so no significant enhancement in the solar wind speed is expected neither.
Forecaster: Ezgi Gülay
MSc. Student
Faculty of Aeronautics and Astronautics, ITU
Supervisor: Dr. Emine Ceren Kalafatoğlu Eyigüler