Viewing archive of Friday, 31 December 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Dec 31 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
31 Dec 2021	100	004
01 Jan 2022	098	010
02 Jan 2022	096	021

Bulletin

NOAA region 2918 (Catania group 96) produced a few more C flares while in decay. The largest was a C9.8 flare peaking at 6:56UT. The most significant region on disc remains NOAA region 2916 which continues to have mixed polarity fields in the trailing part. It nevertheless remained quiet and stable. The two unipolar regions on disc (NOAA 2917 and 2919) remained unipolar while a new region is starting to emerge around S15E32. Flaring at C level remains likely with only a limited chance for flaring to reach M class levels.

No Earth directed CMEs have been observed in coronagraph data.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2MeV electron flux remained under the 1000 pfu threshold. The 24h electron fluence was at normal levels and is expected to be at normal levels over the next 24 hours. Electron fluxes could start building up again in the next days with the expected elevated Solar wind speeds.

Solar wind remained only slightly elevated but showed an overall return to slow Solar wind conditions. Solar wind speed decreased from around 500km/s to 430km/s. The magnetic field magnitude hovered around a nominal 4nT value. The magnetic field phi angle indicated connection to a positive polarity sector. A further decrease to slow Solar wind conditions is expected over the next 24 hours. This is expected to be followed by a renewed increase starting around midnight 1-2 January related to another equatorial positive polarity coronal hole that crossed the central meridian December 29-30.

Geomagnetic conditions were mostly quiet (NOAA Kp 0-2) with only an isolated period of unsettled conditions locally (local K Belgium reaching 3 early in the period). Geomagnetic conditions are expected to be quiet over the next 24 hours before reaching unsettled conditions and potentially active levels in response to the elevated Solar wind conditions by early January 2.

Today's estimated international sunspot number (ISN): 060, based on 14 stations.

Solar indices for 30 Dec 2021

Wolf number Catania	///
10cm solar flux	102
AK Chambon La Forêt	008
AK Wingst	010
Estimated Ap	008
Estimated international sunspot number	072 - Based on 14 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page