Predikce sluneční a geomagnetické aktivity

Solar activity forecast for the period

February 14 - February 20, 2025

Activity level:	low to moderate
X-ray background flux (1.0-8.0 A):	in the range B9.8-C5.0
Radio flux (10.7 cm):	a fluctuation in the range 110-250
Events:	class C (4-15/day), class M (4-17/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri):	in the range 70-220

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

Geomagnetic activity forecast for the period

February 14 - February 20, 2025

Quiet:	Feb 19 - 20
Unsettled:	Feb 14 - 15, 17 - 19
Active:	Feb 16 - 18
Minor storm:	Feb 13, 16, 18
Major storm:	0
Severe storm:	0
Geomagnetic activity summary:	Next week, we expect three active events with possible minor storming events. The first one is expected tonight (February 13) because of the coronal hole 14/-4. The other ones have been expected about Sunday, February 16, and also about Tuesday, February 18. Between these active episodes, we expect at most unsettled conditions. The last days, February 19 - 20, we expect geomagnetic activity decrease to quiet level.

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

Geomagnetic activity forecast for the period

February 14 - February 20, 2025

Remarks:

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere February 14 - February 20, 2025
Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – February 13, 2025

Total solar activity was highest last October in the current 11-year cycle. Since then, it has been declining, but slowly. This is also true for flare activity. Medium strong solar flares were produced mainly by the active region of AR3981. Some of these were accompanied by CMEs, none of which hit the Earth directly, but passed close enough to affect its atmosphere.

NOAA predicted on February 8 that there was a possibility of G1 class geomagnetic storms on February 10 and 11. The prediction turned out to be fairly accurate - although geomagnetic field activity increased as early as February 9, it was highest on February 10 and was elevated on February 11. Therefore, ionospheric shortwave propagation conditions were at their worst on 10 February and subsequently improved only very slowly in the following days.

We now observe a large coronal hole, resembling a canyon, on the Sun, which could be another source of enhanced solar wind. Earth should be hit by it on Valentine's Day, or February 14. The days ahead will also be rather unsettled, but the active regions now rising near the southeastern limb of the solar disk will cause an uptick in solar activity, nevertheless, causing improved propagation conditions.

The good news at the end: at https://www.solarham.com/ on the bottom left, after an eleven-week hiatus, we can see a map of the entire Sun, especially the sun's far side, under the "Farside Watch" banner. So the JSOC glitch has been fixed, and after another click on http://jsoc.stanford.edu/data/timed/ we can read more under the heading "Time-Distance Helioseismic Far-Side Imaging".

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

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

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