Past Events
Solar activity was at low levels within the last week. New sunspots groups and active regions, AR2761, AR2762 and AR2763, from the Solar Cycle 25 have emerged on April 28, 30 and May 1, even though, they produced no significant flares. AR2761 was a small sunspot group to hold any threats and AR2762 has turned behind the visible disk on May 3, while AR2763 is still present. Two CMEs were observed from SOHO LASCO C2 on April 27 and 29. Their speeds were measured as 317 and 358 km/s respectively. While the one on 29 was not Earth-directed, the one on 27 was predicted as glancing blow. Solar wind speed varied between 350 and 450 km/s, and the cause of the enhancements were coronal holes. The maximum Kp was 3. There were no magnetopause crossings.
The solar activity was at very low levels within the last 24 hours. There are no sunspots on the visible disk, yet there are two remaining active regions AR2763 and AR2760. There were only background level solar flares. The coronal hole on the South pole has an extended as a straight thin line on the southeast limb. The coronal hole at the North poles is smaller than the one on the other pole. The solar wind speed was low compared to the rest of the week. It fluctuated between 278 and 343 km/s. The strength of southward IMF component was 5.5 nT at its maximum. The minimum magnetopause standoff distance was 8.5 Re. The planetary Kp was 3 at its maximum. The geomagnetic indices Dst and AE were at levels which oppose no threat. The F10.7 radio flux data was 69 which is normal during solar minimum.
The solar activity is expected to remain at low levels in the following days. ASSA flare model predicts the occurrence possibility of C, M and X class flares as, 6%, 1% and 0% respectively. IPS is expected on May 5 due to the arrival of the CME happened on April 27. Thus changes in the geomagnetic environment and slight increase in the levels are expected. Also in the following days, an increase is expected in solar wind speed up to no more than 450 km/s due to the observed coronal holes on May 1.
Forecaster: Ezgi Gülay
MSc. Student
Faculty of Aeronautics and Astronautics, ITU
Supervisor: Dr. Emine Ceren Kalafatoğlu Eyigüler