Affichage des archives de mercredi, 31 décembre 2025

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Dec 31 1236 UTC

Prévisions SIDC

Éruptions solaires

M-class flares expected (probability >=50%)

Géomagnétisme

Minor storm expected (A>=30 or K=5)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
31 Dec 2025	179	024
01 Jan 2026	176	028
02 Jan 2026	176	018

Régions solaires actives et éruptions solaires

Solar flaring activity was low over the past 24 hours, with only C-class flares recorded. The largest flare was a C5.9 flare (SIDC Flare 6546) peaking on December 31 at 01:32 UTC, which was produced by SIDC Sunspot Group 745 (NOAA Active Region 4325). This region is the largest on disk and was responsible for most of the flaring activity (Beta-Delta magnetic configuration). There are currently 8 numbered regions on the disk. SIDC Sunspot Group 740 (NOAA Active Region 4321) has rotated over the west limb. SIDC Sunspot Groups 744 and 735 (NOAA Active Regions 4324 and 4317, respectively) are the other notable regions on disk but were mostly quiet. A new region emerged in the eastern hemisphere (SIDC Sunspot Group 750, N14E40) and SIDC Sunspot Group 712 (NOAA Active Regions 4330) decayed. The remaining regions are simple and mostly quiet. Solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares expected and a chance for X-class flares.

Éjection de masse coronale

No new Earth-directed CMEs were observed in the available coronagraph imagery.

Vent solaire

Over the past 24 hours, the solar wind parameters reflected a slow solar wind regime. The solar wind speed ranged between 370 and 460 km/s. The interplanetary magnetic field ranged between 2 and 10 nT, and Bz had a minimum of -6 nT. The interplanetary magnetic field phi angle was mostly in the positive sector (directed away from the Sun). Enhanced solar wind conditions are expected over the next 24 hours, due the combined effect of the high speed stream arrival associated with SIDC Coronal Hole 140 (negative polarity) and the glancing blow of a CME from December 28.

Géomagnétisme

Geomagnetic conditions were at quiet to unsettled levels globally (NOAA Kp 1 to 3) and locally (K BEL 1 to 3) over the past 24 hours. Minor storm conditions are expected with possible moderate storm intervals possible, due to the expected high speed stream and CME arrival.

Niveaux de flux de protons

The greater than 10 MeV proton flux was below the 10 pfu threshold over the past 24 hours. It is expected to remain below this threshold level over the next 24 hours.

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV electron flux, as measured by GOES-18 and GOES-19 satellites, was above the 1000 pfu threshold for the first part of the period and decreased below it from 09:00 UTC December 31. The greater than 2 MeV electron flux is expected to again briefly exceed the 1000 pfu threshold over the next 24 hours but is expected to continue to gradually decrease from January 01, due to the anticipated high speed stream arrival. The electron fluence was at moderate levels and is expected to be at low to moderate levels for the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 137, sur la base de 09 stations.

Indices solaires pour 30 Dec 2025

Nombre de Wolf, observé par Catania	115
Flux solaire à 10 cm	182
AK Chambon La Forêt	014
AK Wingst	008
Ap estimé	007
Nombre international de taches solaires estimé	139 - Basé sur 20 stations

Résumé des événements marquants

Données fournies par le Solar Influences Data analysis Center© - SIDC - Traité par SpaceWeatherLive

Toutes les heures sont indiquées en UTC

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