Solar activity forecast for the period December 10 - December 16, 2021

Activity level: mostly very low 
X-ray background flux (1.0-8.0 A): in the range A1.0-A7.5
Radio flux (10.7 cm): a fluctuation in the range 75-82
Events: class C (0/period), class M (0/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 0-60

Martina Pavelkova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic
e-mail: sunwatch(at)asu.cas.cz

Geomagnetic activity forecast for the period December 10 - December 16, 2021

Quiet: Dec 10 - 12
Unsettled: Dec 13 - 16
Active: Dec 13 - 14
Minor storm: possible Dec 13 - 14
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:
Currently, geomagnetic field is quiet.
Next days, till December 13, we expect at most quiet conditions 
remaining.
Geomagnetic activity enhancement is expected about Monday, December 13. 
Between December 13 - 14, an active event is possible with minor 
probability of minor storm effect. After this active episode, we expect 
geomagnetic activity decrease to generally unsettled level. Last day of 
currently forecasted period, we expect quiet to unsettled conditions 
return.

Tomas Bayer
RWC Prague
Institute of Geophysics of the ASCR, Prague
Department of Geomagnetism
Budkov observatory (BDV)

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere December 09 - December 16, 2021

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere
- December 9, 2021

(Created as a continuation of Earth's magnetic field activity predictions,
published since 1978.)

The only sunspot group on solar disk No. 2904, in which we observed three
spots (=> R = 13) on December 7, was calm and decayed to plage. Thus, R = 0
applies since December 8, so we register a minimum within the
quasi-periodic twenty-seven-day fluctuation. At the same time, the solar
wind has weakened, the geomagnetic field has calmed down and consequently
result are the lowest values of f0F2. However, the decreasing length of
sunshine in the Earth's northern hemisphere also contributes to it.
In the remaining weeks until the end of the year, we can expect a gradual
rise in solar activity to the level of the end of November, an irregular
alternation of the Earth's magnetic field between quiet and unsettled, and
a gradual rise in daily f0F2 values just slightly above average.

F. K. Janda, A.R.S. OK1HH
Emails: ok1hh(at)crk.cz, ok1hh(at)rsys.cz
Pmail: OK1HH(at)OK0NAG.#BOH.CZE.EU