Viewing archive of Monday, 25 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 25 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
25 Oct 2021	095	001
26 Oct 2021	093	007
27 Oct 2021	091	013

Bulletin

Solar activity was at very low levels. NOAA Active Region (AR) 2886 (alpha configuration) continued to decay and has not produced any noticeable activity for several days. NOAA AR 2887 (beta configuration) produced several B-class flares over the last 24 hours and is expected to continue at the same level of activity. NOAA AR 2888 (alpha configuration) has produced a few B-class flares during the last 24 hours and is expected to continue in the same way. Over all, several B-class flares are expected for the next 24 hours, with a fair chance of an isolated C-class flare.

A CME detected over the last 24 hours on the eastern limb of the solar disk is not expected to be geo-effective.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to remain below this threshold during the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain so.

The solar wind speed (as measured by DSCOVR) ranged between 300 to 380 km/s. The total magnetic field ranged from 2 nT to around 7 nT. The Bz varied between -4 and +5 nT. The interplanetary magnetic field phi angle was predominantly in the negative sector (directed towards the Sun). The solar wind speed is expected to continue to reflect a slow solar wind regime for the next 24 hours.

Geomagnetic conditions were at quiet levels (NOAA Kp and local K Dourbes 0-2). Geomagnetic conditions are expected to remain quiet for the next 24 hours.

Today's estimated international sunspot number (ISN): 063, based on 16 stations.

Solar indices for 24 Oct 2021

Wolf number Catania	///
10cm solar flux	093
AK Chambon La Forêt	009
AK Wingst	004
Estimated Ap	004
Estimated international sunspot number	037 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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