Predikce sluneční a geomagnetické aktivity

Solar activity forecast for the period

March 14 - March 20, 2025

Activity level:	low to moderate
X-ray background flux (1.0-8.0 A):	in the range B9.5-C5.0
Radio flux (10.7 cm):	a fluctuation in the range 90-170
Events:	class C (3-15/day), class M (2-13/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri):	in the range 70-160

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

Geomagnetic activity forecast for the period

March 14 - March 20, 2025

Quiet:	Mar 19 - 20
Unsettled:	Mar 14 - 19
Active:	Mar 14 - 15, 17 - 18
Minor storm:	Mar 14 - 15, 17
Major storm:	0
Severe storm:	0
Geomagnetic activity summary:	Next week, we expect the general geomagnetic activity at unsettled to active level. An active event with possible minor storm effect can occur about Friday/Saturday, March 14 - 15, and also the first half of the next week. At the end of currently forecasted period, we expect geomagnetic activity decrease to quiet to unsettled level.

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

Geomagnetic activity forecast for the period

March 14 - March 20, 2025

Remarks:

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – March 13, 2025

The two geomagnetic disturbances (8-9 March and 12-13 March) were both triggered by an enhanced solar wind blowing from the border between the coronal holes and the adjacent active sunspot group. OM Kevin VE3EN has largely restored the content of his website https://www.solarham.com/, so that we could conveniently observe the entire solar evolution in the five images at the top of the main page (HMI Intensity, HMI Magnetogram, Coronal Holes, AIA 131, and SUVI 304). Again, it is not surprising that both disturbances were correctly predicted, including the expected worsening on the second day of each disturbance (March 9 and March 13).

Even with thanks to relative simplicity of the situation and the clear images, it was not surprising that both disturbances were predicted (including the likely deterioration on the second day of each disturbance, i.e. 9 and 13 March). Both disturbances were followed by only gradual improvement, i.e. a return to normal.

If solar activity had been higher, the improvement after the disturbances would have been faster. However, there was no large area of spots on the Sun this time, and certainly not any with a more complex configuration of magnetic fields.

In the second half of March, solar activity will increase slightly and the spring equinox will occur. While until recently it appeared that the increase in solar activity would be more rapid, even the current expectation of solar flux values only slightly above 200 s.f.u. should result in a noticeable overall improvement, including an increase in MUF at mid-latitudes during the day up to the VHF region.

F. K. Janda, A.R.S. OK1HH

e-mail: ok1hh(at)crk.cz; ok1hh(at)rsys.cz

Pmail: OK1HH(at)OK0NAG.#BOH.CZE.EU