Viewing archive of Thursday, 2 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 02 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
02 Sep 2021	085	019
03 Sep 2021	085	011
04 Sep 2021	084	007

Bulletin

X-ray flux was mostly below C level apart from a single C1.2 flare early in the period from Catania group 32 (NOAA 2860). Catania group 33 (NOAA 2859) decayed to plage while Catania group 32 (NOAA 2860), still the most complex region on disc, seems to simplify as it is rotating towards the West limb. A new bipolar region (currently unnumbered) emerged in the South-Western quadrant. It 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.

The negative polarity coronal hole in the southern hemisphere that is currently transiting the central meridian is expected to influence Solar wind conditions near Earth on September 5.

Solar wind is in a slow Solar wind regime with no obvious signs of arrival of either the August 26 or the August 28 CME. Solar wind speed was mostly in the 305-345 km/s range. Interplanetary magnetic field was below or around 5nT with an unremarkable Bz component. The orientation of the Interplanetary magnetic field was mostly away from the Sun. There is still the possibility of Solar wind conditions to enhance later today with a later than expected arrival of the August 28 CME. If this arrives, enhanced conditions are expected to last into September 3 and 4. Solar wind enhancements related to the fast wind from the negative polarity coronal hole in the southern hemisphere are only expected from September 5 onwards.

Geomagnetic conditions have been quiet (NOAA Kp 0-1 and local K Dourbes 0-2). Active conditions are possible over the next 24-48 hours with the possible August 28 CME arrival.

Today's estimated international sunspot number (ISN): 032, based on 18 stations.

Solar indices for 01 Sep 2021

Wolf number Catania	041
10cm solar flux	084
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	004
Estimated international sunspot number	033 - Based on 22 stations

Noticeable events summary

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

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