Viewing archive of Friday, 3 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 03 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
03 Sep 2021	085	006
04 Sep 2021	085	008
05 Sep 2021	085	024

Bulletin

X-ray flux was mostly below C level again only interrupted by a single C1.2 flare (peaking at 20:55) from Catania group 32 (NOAA 2860) which is approaching the West limb. The new bipolar region (NOAA 2863) that emerged in the South-Western quadrant yesterday grew and consolidated but appears stable and inactive. C-flaring is still rather probable in the next 24 hours.

There were no new Earth directed CMEs observed in available coronagraph data.

The greater than 10 MeV proton flux was at background levels and we expect it will remain so in the next 24 hours. The greater than 2 MeV electron flux reached again above the 1000 pfu threshold during its diurnal maximum both yesterday and today. The 24h electron fluence is at moderate levels and we expect it to be normal to moderate over the next days with a decaying trend.

The negative polarity coronal hole in the southern hemisphere that has just transited the central meridian is only expected to start influencing Solar wind conditions near Earth on September 5.

Solar wind parameters were indicative of a slow Solar wind regime. Solar wind speed was roughly around 350 km/s and interplanetary field had a magnitude of around 5nT. Bz showed this morning a period of somewhat sustained negative values down to -5.8nT. The orientation of the interplanetary magnetic field was mostly away from the Sun. There seem to be no obvious signs of the expected arrival of the August 28 CME. Hence, essentially slow Solar wind conditions are expected until the morning of September 5, when enhancements become possible, related to the high speed stream from the negative polarity coronal hole in the Southern hemisphere that has just transited the central meridian. The associated enhancements are expected to be only minor though.

Geomagnetic conditions were quiet (both NOAA Kp and local K Dourbes 0-2). Quiet geomagnetic conditions are expected until September 5, when they may rise to unsettled and active conditions associated to the possible enhanced Solar wind conditions.

Today's estimated international sunspot number (ISN): 020, based on 22 stations.

Solar indices for 02 Sep 2021

Wolf number Catania	///
10cm solar flux	086
AK Chambon La Forêt	007
AK Wingst	005
Estimated Ap	003
Estimated international sunspot number	032 - Based on 28 stations

Noticeable events summary

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

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