Hvezdáreň Roztoky

September 17 – 23, 2021

Solar activity forecast for the period September 17 – 23, 2021

Issued: 2021 Sep 16 2100 UTC

Activity level from Sep 17 to Sep 20: very low to low
X-ray background flux (1.0-8.0 A): in the range A4.0-B3.0
Radio flux (10.7 cm): a fluctuation in the range 70-85 f.u.
Events: class C (0-8/day), class M (0/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 0-40

Activity level from Sep 21 to Sep 23: very low to low
X-ray background flux (1.0-8.0 A): in the range A3.0-B3.0
Radio flux (10.7 cm): a fluctuation in the range 70-90 f.u.
Events: class C (0-8/day), class M (0-1/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 0-50

Jozef Lesko
Roztoky Observatory, Slovak Republic
www.osveta.sk/n/11283/astronomia.html
e-mail: safor (at) protonmail.ch

Geomagnetic activity forecast for the period September 17 – 23, 2021

Issued: 2021 Sep 16 2130 UTC

Quiet to unsettled: Sep 17 – 23

Jozef Lesko
Roztoky Observatory, Slovak Republic
www.osveta.sk/n/11283/astronomia.html
e-mail: safor (at) protonmail.ch