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Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Oct 24 1231 UTC

Prévisions SIDC

Éruptions solaires

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

Géomagnétisme

Quiet (A<20 and K<4)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
24 Oct 2025	129	012
25 Oct 2025	127	017
26 Oct 2025	130	017

Régions solaires actives et éruptions solaires

Solar flaring activity was low over the past 24 hours, with several C-class flares recorded. The largest flare was a C2.9 flare (SIDC Flare 5864), peaking at 02:57 UTC on October 24, associated with SIDC Sunspot Group 672 (NOAA Active Region 4256). There are currently eight numbered active regions on the visible solar disk. Low flaring activity was also produced by SIDC Sunspot Group 653 (NOAA Active Region 4267; magnetic type alpha). The remaining active regions are relatively simple (magnetic type alpha or beta) and did not produce any significant flaring activity. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares very likely and a small chance for M-class flares.

Éjection de masse coronale

A faint coronal mass ejection (SIDC CME 586) was observed in SOHO/LASCO-C2 imagery, starting at 14:36 UTC on October 23. The CME is directed primarily toward the southwest from Earth's perspective and is possibly associated with a small eruption near SIDC Sunspot Group 672 (NOAA Active Region 4256). While the bulk of the ejecta is expected to miss Earth, a glancing blow cannot be fully excluded. Further analysis is ongoing. No other Earth-directed CMEs were detected in the available coronagraph imagery over the past 24 hours.

Vent solaire

Over the past 24 hours, the solar wind parameters were slightly disturbed. The interplanetary magnetic field reached values up to 10 nT before decreasing to around 6 nT. The solar wind speed increased from about 450 km/s to 570 km/s. The southward component of the interplanetary magnetic field fluctuated between -7 nT and 8 nT. The magnetic field orientation was predominantly in the negative sector (field directed towards the Sun). Solar wind conditions are expected to remain slightly elevated over the next days due to the arrival of a high-speed stream from a small equatorial negative polarity coronal hole (SIDC Coronal Hole 133).

Géomagnétisme

Geomagnetic conditions were quiet to unsettled globally and quiet locally over Belgium (NOAA Kp: 1 to 3; K-Bel: 1 to 2). Mostly unsettled geomagnetic conditions are expected over the next 24 hours, with a chance of isolated active periods due to the high-speed stream arrival from a small equatorial negative polarity coronal hole (SIDC Coronal Hole 133).

Niveaux de flux de protons

The greater than 10 MeV proton flux, as measured by GOES-18, was slightly elevated over the past 24 hours but remained well below the 10 pfu threshold. It is expected to remain below the 10 pfu threshold 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 below the 1000 pfu threshold. The greater than 2 MeV electron flux is expected to remain below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence was at normal levels and is expected to be at normal levels over the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 100, sur la base de 19 stations.

Indices solaires pour 23 Oct 2025

Nombre de Wolf, observé par Catania	107
Flux solaire à 10 cm	130
AK Chambon La Forêt	014
AK Wingst	006
Ap estimé	005
Nombre international de taches solaires estimé	100 - Basé sur 17 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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