Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Dec 16 1231 UTC

Prévisions SIDC

Éruptions solaires

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

Géomagnétisme

Active conditions expected (A>=20 or K=4)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
16 Dec 2025	118	008
17 Dec 2025	116	010
18 Dec 2025	114	016

Régions solaires actives et éruptions solaires

Solar flaring activity during the last 24 hours has been low, with only a few C-class flares. The strongest flare was a C3.9 flare (SIDC Flare 6435) from beyond the west limb, peaking at 17:28 UTC on December 15. There are currently seven numbered active regions on the solar disk. The most complex ones have a beta magnetic type. SIDC Sunspot Group 718 (NOAA Active Region 4304) has rotated behind the west limb. SIDC Sunspot Group 726 has decayed into plage. SIDC Sunspot Group 728 (NOAA Active Region 4310, magnetic type beta) has emerged in the northwest quadrant. SIDC Sunspot Group 729 (magnetic type alpha) has emerged in the northeast quadrant. The solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected and a small chance for M-class flares.

Éjection de masse coronale

No Earth-directed Coronal Mass Ejections (CMEs) were observed in the available coronagraph imagery over the last 24 hours.

Trous coronaux

The southern, mid-latitude, negative polarity coronal hole (returning SIDC Coronal Hole 137) has been crossing the central meridian since December 15.

Vent solaire

The solar wind conditions (ACE) during the last 24 hours were enhanced, likely under the ongoing influence of a high-speed stream from the northern, negative polarity coronal hole (SIDC Coronal Hole 142). The solar wind speed increased from 430 km/s to around 610 km/s. The interplanetary magnetic field increased from 4 to 14 nT. The Bz component was mostly positive with values up to 13 nT. The interplanetary magnetic field angle phi was mostly negative. Enhanced solar wind conditions are possible over the next 24 hours.

Géomagnétisme

Geomagnetic conditions globally and locally were quiet to unsettled (NOAA Kp 1 to 3+, K Bel 1 to 3) during the last 24 hours. Quiet to unsettled conditions, with a small chance of isolated periods of active conditions (NOAA Kp 4), are expected over the next 24 hours.

Niveaux de flux de protons

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

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was close to the 1000 pfu threshold but remained below it during the last 24 hours. It is expected to remain mostly below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels and is expected to remain so over the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 072, sur la base de 06 stations.

Indices solaires pour 15 Dec 2025

Nombre de Wolf, observé par Catania	110
Flux solaire à 10 cm	118
AK Chambon La Forêt	012
AK Wingst	006
Ap estimé	004
Nombre international de taches solaires estimé	071 - Basé sur 15 stations

Résumé des événements marquants

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