Last Week
Within the last week, the solar activity was at low levels at the visible side of the Sun, yet the far side of the Sun was pretty active. Three C-class and one M1.4 class solar flares were observed at AR12898 which was turning the far side of the Sun at the southwest limb. The three C-class flares were observed on December 4, and the M-class observed on December 5. All of the flares also erupted with various CMEs. There were total 10 CMEs recorded on December 4 and 5, and 10 more within the rest of the week. 11 of them were S type and 9 of them were C type. Most of the CMEs were not Earth-directed. Only the ones on December 5 at 14:36 and on December 6 at 05:48 were Earth-directed which will be discussed on forecast section.
Within the last 24 hours the solar activity was at low levels. The sun was a spotless disk for the first time since October 17, 2021. There were no significant solar flares. The only coronal hole was in the North pole. The solar wind speed varied between 350 and 440 km/s. The strength of the southward IMF was -5.59 nT at its maximum. The minimum magnetopause standoff distance was 10 Re. The maximum Kp indice was 2. The minimum Dst was -18 nT, and the maximum AE was less than 500 nT which indicate no geomagnetic disturbance. The F10.7 radio flux was 77 sfu which is normal for solar minimum and slightly lower than it was for the last months.
Solar activity is expected to remain at low levels, yet the geomagnetic conditions are expected to be in slightly unsettled conditions for the later hours of December 9 and for the latter days due to the filament eruption on December 5. The filament eruption observed from SDO AIA 304 imagery at December 5 around 11:30 UTC. That filament eruption caused a S-type Earth-directed CME with a speed of 248 km/s at around latitudes -26 and longititudes -1 according to iSWA ENLIL model. This CME is expected to arrive as a glancing blow at the southern hemisphere of our planet.
There are no HSS is expected due to the absence of any coronal holes other than the one on north pole. ASSA flare model predicts the occurrence possibility of C, M and X class flares as, 6%, 1% and 0% respectively. Kp level is expected to be 3 at maximum for the following days.
Forecaster: Ezgi Gülay
MSc. Student
Faculty of Aeronautics and Astronautics, ITU
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