Weekly forecast

Solar activity forecast for the period September 01 - September 07, 2023

Activity level: mostly low 
X-ray background flux (1.0-8.0 A): in the range B5.0 - B8.5
Radio flux (10.7 cm): a fluctuation in the range 80-130
Events: class C (1-10/day), class M (0-4/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 80 - 150

Martina Pavelkova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic

Geomagnetic activity forecast for the period September 01 - September 07, 2023

Quiet: Sep 1 - 2, 6 - 7
Unsettled: Sep 2 - 4
Active: Sep 4 - 5
Minor storm: 0
Major storm: 0
Severe storm: 0

Next week, at most, we expect quiet to unsettled conditions This field 
character can be interrupted by one active episode about Monday, 
September 4, and Tuesday, September 5. Except this possible but unlike 
episode, we expect at most quiet to unsettled conditions.

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 September 01 - September 07, 2023

On 27 August, we predicted a rise in geomagnetic activity, triggered by the
arrival of particles from the filament solar flares three days earlier. It
did occur, but to a lesser extent than we expected. No significant solar
flare (at least of M-class) was observed until 25 August, which is somewhat
surprising for the current phase of Cycle 25 development.

We did not see a major class flare until August 26 at 2250 UT, and it was
an M1-class solar flare, hidden behind the Sun's eastern edge, but it was a
long duration eruption (LDE). It was accompanied by a CME, which of course
was not heading towards Earth, but in this case towards Mars (which it
should hit on September 1).

The coronal mass ejection (CME) was observed on August 29 at about 17:48
UTC near the coordinates N05W35. Another major solar flare, C3, was
observed on August 30 with a maximum at 2334 UT at AR 3413. Prior to that,
a filament of solar plasma disappeared near S18W24 in 2015 UT. Still, we
expect only a slight increase in Earth's magnetic field activity in the
next few days.

Ionospheric shortwave propagation conditions have varied erratically, with
partial credit due to the sporadic E layer that occurred irregularly in
Earth's northern hemisphere late this summer.

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

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