Viewing archive of Thursday, 30 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 30 1232 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
30 Sep 2021	102	013
01 Oct 2021	102	016
02 Oct 2021	102	007

Bulletin

Four active regions (ARs) present on the visible solar disk. NOAA AR 2877 and 2880 have beta-gamma magnetic field configuration. The former produced three C-class flares, the strongest being a C2.8 flare peaking at 21:56 UT on 29 September. There is one more AR rotating into view from the east limb (in the southern hemisphere) that could also contribute to solar activity. Over the next 24 hours, more C-class flares can be expected and M-class flares are possible.

No Earth directed CMEs have been observed in the last 24 hours.

The greater than 10 MeV proton flux was at background levels in the past 24 hours, and is expected to stay there in the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, it may increase over the next 24 hours. The electron fluence was at normal levels over the past 24 hours, it may increase over the next 24 hours.

The solar wind at the Earth has a speed of 400 km/s with magnetic field intensity around 3 nT. Over the next 24 hours we expect an ICME to arrive.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 1-2 and K Dourbes 0-3) over the past 24 hours. Active to moderate storm conditions can be expected with the arrival of the CME from 28 September.

Today's estimated international sunspot number (ISN): 043, based on 14 stations.

Solar indices for 29 Sep 2021

Wolf number Catania	119
10cm solar flux	102
AK Chambon La Forêt	009
AK Wingst	005
Estimated Ap	005
Estimated international sunspot number	069 - Based on 28 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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