Last week
Since our last forecast on November 19, the Sun showed us again that it going towards solar maximum. There was 4 C type CMEs and two of them were Earth-directed. The CME erupted on November 24 had 561 km/s speed and it caused interplanetary shock and caused Kp to increase up to 3 from 1 for the majority of the day.The other Earth-directed CME erupted on November 29 and it still have not arrived! It will be discussed in the forecast part.
Solar wind speed is over 400 km/s since 30 November due to the coronal holes. The first impact of the high speed stream also caused an interplanetary shock and caused Kp to increase to 5! Also caused radiation belt enchancement due to increased energetic electron flux. Our geospace environment has still disturbed since then.
Within the last 24 hours the solar activity were at quiet to moderate levels. HSS has been still continuing with a speed varied between 424 and 531 km/s. Even though there is not an ongoing geomagnetic storm, the geomagnetic environment is disturbed with low Dst which lower than -18 nT and high AE between 500 and 1000 nT. This HSS is caused by the coronal holes located at west side of the visible disk. Strength of the southward component of the interplanetary magnetic field was -5.25 nT at its maximum which is relatively high but not threatening.
There are 45 sunspots on the visible disk as we see the increase in the number day by day. There are four active regions but there was no solar flares within the last 24 hours. F10.7 radio flux is 87 sfu which is normal during the ascending phase of the solar cycle.
Solar activity is expected to remain at unsettled conditions due to active regions, and coming CME from November 29. The CME was expected to arrive at Earth at December 2 10.55 UTC according to ENLIL model by NASA. Yet, it seems like the CME is going to affect the Earth as a glancing blow at the south part of the Earth, but the effect of the CME has already arrived yesterday with increased levels in solar wind parameters.
Solar wind is expected to remain at high for the next day but then decrease slowly as the coronal holes turns to the west side of the Sun. ASSA flare model predicts the occurrence possibility of C, M and X class flares as, 15%, 2% and 0% respectively.
Forecaster: Ezgi Gülay
MSc. Student
Faculty of Aeronautics and Astronautics, ITU
Supervisor: Dr. Emine Ceren Kalafatoğlu Eyigüler
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