Viewing archive of Wednesday, 27 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 27 1232 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
27 Oct 2021	110	003
28 Oct 2021	100	004
29 Oct 2021	090	007

Bulletin

Solar flaring activity was moderate during the last 24 hours, with an M1 flare detected on 16 Oct 15:57 UT at N13E89 (possibly NOAA returning active region 2885). Several C-class flares were detected from NOAA Active Region (AR) 2887 (Beta magnetic configuration) and from the two returning ARs, while NOAA 2889 (Beta magnetic configuration) produced one C-class flare. The ARs 2886, 2888 (both with Alpha magnetic configuration) and 2890 (Beta magnetic configuration) did not produced any significant activity. Several C-class flares are expected for the next 24 hours (mostly from the NOAA AR 2887 and the two returning ARs), and there is a good chance of one or more M-class flares.

No Earth directed CMEs have been detected in the available coronagraph imagery. A few CMEs and outward flows were detected by CACTUS from SOHO/LASCO-C2 data during the last 24 hours, however those events took place at the east of the solar limb and they are 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) increased from 310 to 420 km/s during the last 24 hours. The total magnetic field ranged from 1 nT to around 7 nT, while the Bz varied between -4 and +5 nT in the last 24 hours. The interplanetary magnetic field phi angle was predominantly in the negative sector (directed towards the Sun) during the last 24 hours. The solar wind conditions are expected to remain in the slow solar wind regime for the next 24 hours.

Geomagnetic conditions were globally and locally quiet (NOAA Kp and K Dourbes indices 1-2). Geomagnetic conditions are expected to remain quiet for the next 24 hours.

Today's estimated international sunspot number (ISN): 101, based on 17 stations.

Solar indices for 26 Oct 2021

Wolf number Catania	///
10cm solar flux	109
AK Chambon La Forêt	008
AK Wingst	005
Estimated Ap	004
Estimated international sunspot number	086 - Based on 29 stations

Noticeable events summary

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

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