Past Events
The new year began with the signals of the solar cycle 25. After 40 days without any sunspots, on 23th December 2019, a new sunspot showed itself around 30° south hemisphere and the number of spotless days have not reached 13 since then. Even though it is expected that the solar minimum will continue throughout most of 2020, the solar activity will start to increase eventually. Other than the sign of the new solar cycle, the solar activity was at low levels. There were several significant HSSs, the one on 6th February was the most intense one and the solar wind speed reached almost 700 km per second. Solar flares were remained at background levels. There were a few earth-directed CME's, yet all of them were glancing blows and their speeds did not reach 360 km per second. There was no geomagnetic storm, magnetopause crossings, SEP or magnetopause crossings.
Within the last 24 hours, the solar activity was at very low levels. The Sun was a spotless disk without any sunspot groups and active region. Solar flares were at background levels. No CMEs were observed. Other than the coronal hole at the south pole, there is another small CH located at southeast limb and very close to the center. The solar wind speed varied between 336 and 419 km per second. The southward interplanetary magnetic field strength was 1.6 nT at maximum. The minimum magnetopause standoff distance was 11 Re. The maximum Kp was 2. The geomagnetic storm indices Dst and AE was measured between -12 and 3 nT, and less than 500 nT respectively. The F10.7 solar flux unit is 71 sfu which is normal at solar minimum.
The solar activity is expected to be at low levels in the following days. A slight increase at the solar wind speed is expected due to the CH at the southeast limb. No interplanetary shocks are expected since no CME is observed. ASSA model predicts the possibility of C, M and X flares are 9%, 1% and 0% respectively. Geomagnetic conditions are expected to remain at quiet conditions as well.
Forecaster: Ezgi Gülay
Msc. Student
Faculty of Aeronautics and Astronautics, ITU
Supervisor: Dr. Emine Ceren Kalafatoğlu Eyigüler