Affichage des archives de lundi, 27 octobre 2025

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Oct 27 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
27 Oct 2025	124	019
28 Oct 2025	124	054
29 Oct 2025	124	029

Régions solaires actives et éruptions solaires

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 8 numbered sunspot groups were identified on the disk over the past 24 hours. The largest flare was a C1.7 flare (SIDC Flare 5879) peaking on October 27 at 10:21 UTC, which was produced by SIDC Sunspot Group 674 (NOAA Active Regions 4257, 4262). 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 wide CME (angular width of about 100 degrees) was first observed in LASCO C2 at 20:00 UT on 26 October. We are currently waiting for additional data in order to better assess whether the CME has an Earth-directed component; if so, a possible arrival on 29 October cannot be excluded.

Trous coronaux

A recurrent large coronal hole, SIDC Coronal Hole 123 (mid- latitude coronal hole with a positive polarity), first reached the central meridian on October 25.

Vent solaire

Over the past 24 hours, solar wind parameters (ACE and DSCOVR) reflected a slow solar wind regime. The solar wind speed ranged between 400 km/s and 350 km/s. The interplanetary magnetic field is around 6 nT. Slow solar wind conditions are expected over the next 24 hours, with a chance of a weak enhancement on 27 October due to possible glancing blow from the CME on 23 October (SIDC CME 586). A high speed stream is expected in 24 hours from a large positive polarity coronal hole (SIDC Coronal Hole 123).

Géomagnétisme

Geomagnetic conditions were quiet globally and quiet to unsettled locally over Belgium (NOAA Kp: up to 1; K-Bel: up to 2). There’s a small chance of active to minor storm periods today due to a possible glancing blow from the CME from 23 October (SIDC CME 586). In about 24 hours, the expected high-speed stream arrival from a large recurrent positive polarity coronal hole (SIDC Coronal Hole 123) may cause moderate storm levels.

Niveaux de flux de protons

The greater than 10 MeV GOES proton flux was below the 10 pfu threshold level over the past 24 hours and is expected to remain so for 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 : 090, sur la base de 13 stations.

Indices solaires pour 26 Oct 2025

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	124
AK Chambon La Forêt	007
AK Wingst	005
Ap estimé	004
Nombre international de taches solaires estimé	104 - Basé sur 19 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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