Viewing archive of Wednesday, 29 December 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Dec 29 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
29 Dec 2021	119	013
30 Dec 2021	117	021
31 Dec 2021	115	010

Bulletin

Solar activity was again dominated by another M flare from NOAA region 2918 (Catania group 96) which peaked at 16:11UT at M1.6 magnitude. The 2918 region continues to contain mixed polarity field in the leading area and is now classified as beta-gamma. NOAA region 2916 (Catania group 97) is the other most prominent region on disc but remained quiet during the period. The bipolar region 2920 (Catania group 93) is in decay while Catania group 94, the new bipolar region that developed yesterday in the North-Western quadrant, was numbered NOAA region 2921, but remained quiet. Two additional simple alpha regions are present on the disc (NOAA 2917 and 2919). Overall, flaring at C class is to be expected with a small chance for another M flare continuing to exist.

No other 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. A renewed rise in electron fluxes could build up in the next days with the expected high speed stream conditions.

Another equatorial positive polarity coronal hole is transiting the central meridian and may influence Solar wind conditions from January 1 onwards.

Solar wind has seen a return to slow Solar wind conditions. Solar wind speed has decreased to under 400 km/s and the magnetic field magnitude has decreased to mostly around 5nT. The magnetic field phi angle indicated connection to a positive polarity sector. Solar wind conditions are expected to increase again today in relation to the positive polarity coronal hole that crossed central meridian on December 26.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 1-3 and local K Belgium 0-3). Geomagnetic conditions may reach active levels associated to the expected Solar wind enhancements.

Today's estimated international sunspot number (ISN): 085, based on 04 stations.

Solar indices for 28 Dec 2021

Wolf number Catania	081
10cm solar flux	121
AK Chambon La Forêt	///
AK Wingst	009
Estimated Ap	008
Estimated international sunspot number	102 - Based on 16 stations

Noticeable events summary

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

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