Viewing archive of Saturday, 4 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 04 1231 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
04 Sep 2021	085	008
05 Sep 2021	085	024
06 Sep 2021	086	012

Bulletin

X-ray flux remained below C level throughout the period. Catania group 32 (NOAA 2860) now rotated off the disc. The bipolar region (NOAA 2863) in the South appears stable and inactive. Two new bipolar regions also emerged in the North Eastern quadrant, but have not shown very active. Another region has also turned onto the disc in the South East and awaits analysis. X-ray flux is expected to remain below C level though with the several regions on disc there always remains a chance for C-flaring.

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 yesterday. 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.

Slow solar wind conditions were recorded. Solar wind speed was between 350-450 km/s. Interplanetary magnetic field strength was around 5nT with an unremarkable Bz component. By tomorrow, September 5, Solar wind may see some weak enhancements associated to a negative polarity coronal hole in the Southern hemisphere.

Geomagnetic conditions were quiet to unsettled (local K Dourbes 0-3 while NOAA Kp 1-2). Initially quiet geomagnetic conditions are expected which by tomorrow may become unsettled with also active periods possible, depending on the strength of the expected Solar wind enhancements.

Today's estimated international sunspot number (ISN): 063, based on 17 stations.

Solar indices for 03 Sep 2021

Wolf number Catania	///
10cm solar flux	084
AK Chambon La Forêt	014
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	022 - 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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