Predikce sluneční a geomagnetické aktivity

Solar activity forecast for the period

September 06 - September 12, 2024

Activity level:	low to moterate, but possibly high
X-ray background flux (1.0-8.0 A):	in the range C1.5 - C7.0
Radio flux (10.7 cm):	a fluctuation in the range 160-330
Events:	class C (2-14/day), class M (1-25/period), class X (0-3/period), proton (0-2/period)
Relative sunspot number (Ri):	in the range 130-350

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

Geomagnetic activity forecast for the period

September 06 - September 12, 2024

Quiet:	Sep 6 - 7, 11
Unsettled:	Sep 6, 10 - 11
Active:	Aug 31, Sep 8 - 9
Minor storm:	Sep 8 - 9
Major storm:	possible Sep 8
Severe storm:	0
Geomagnetic activity summary:	Next two days, we expect at most quiet to unsettled conditions. The next peak of geomagnetic activity is expected at the start of new week, about Sunday, September 8, and Monday, September 9. The expected active episode with possible storming effect is probable because of the new coronal mass ejection observed today, i.e. Thursday, September 5. Then, since September 10, we expect geomagnetic activity decrease to unsettled level and, the last day, at the range of quiet to unsettled conditions.

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

Geomagnetic activity forecast for the period

September 06 - September 12, 2024

Remarks:

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere September 06 - September 12, 2024
Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – September 5, 2024

September 6th was the sixth day of a continuous influx of solar-origin protons into the Earth's atmosphere. The likely source is on the far side of the Sun, probably in AR3792, possibly AR 3796. This influx briefly intensified on 3 September at noon UT.

Overall solar activity remains high. The solar flux is again close to the values measured on August 6-13, about 27 days ago, or during the last solar revolution. Summer in the Earth's northern hemisphere is slowly coming to an end and shortwave propagation conditions should improve on average. Which is happening, but at a slower and more erratic pace. The reason for this is the irregular changes in the activity of the Earth's magnetic field and the parameters of the solar wind. Sometimes the changes are even opposite to what we would expect - for example, on 4 September between 10 - 15 UT there was a rather significant and unexpected increase in geomagnetic activity, without any major changes in MUF and overall propagation conditions.

We are now observing only a single small coronal hole on the Sun now. It is located near the central meridian and there is no active region nearby. Respectively, all three larger ARs, capable of producing eruptions of moderate magnitude, are south of the solar equator. Accordingly, we find no change in the short-term forecasts from the current state. More optimistic are the medium-term forecasts, which take into account seasonal changes.

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

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

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