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Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Oct 03 1231 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

Warning condition (activity levels expected to increase, but no numeric forecast given)

	Flux de 10 cm	Ap
03 Oct 2025	163	016
04 Oct 2025	158	013
05 Oct 2025	155	008

Régions solaires actives et éruptions solaires

Solar flaring activity over the last 24 hours has been moderate, with one M-class flares and a few C-class flares. The strongest flare was an M1.5 flare (SIDC Flare 5665), peaking at 05:23 UTC on October 03, associated with SIDC Sunspot Group 657 (NOAA Active Region 4236, magnetic type beta-gamma). There are currently ten numbered active regions on the solar disk. The most complex is SIDC Sunspot Group 653 (NOAA Active Region 4232, magnetic type beta-gamma-delta). SIDC Sunspot Group 592 (NOAA Active Region 4225) has rotated behind the west limb. SIDC Sunspot Group 648 (NOAA Active Region 4230, magnetic type beta-gamma) and SIDC Sunspot Group 659 (NOAA Active Region 4238, magnetic type beta) are currently rotating across the west limb. SIDC Sunspot Group 662 (magnetic type beta) has emerged in the northeast quadrant. SIDC Sunspot Group 663 (magnetic type beta) has emerged in the southeast quadrant. The solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares very likely and X-class flares unlikely.

Éjection de masse coronale

A wide Coronal Mass Ejection (SIDC CME 569) was observed in LASCO/C2 and LASCO/C3 coronagraph imagery, lifting off the southeast limb around 00:20 UTC on October 03. It is most likely associated with eruptive activity behind the east limb. It is not expected to impact Earth. A second wide Coronal Mass Ejection (SIDC CME 570) was observed in LASCO/C2 coronagraph imagery, lifting off the east limb around 07:00 UTC on October 03. It is most likely associated with the M1.5 flare (SIDC Flare 5665) that peaked at 05:23 UTC on October 03, associated with SIDC Sunspot Group 657 (NOAA Active Region 4236). Current analysis suggests a small chance for a glancing blow arrival starting from the UTC evening on October 06. No other Earth-directed CMEs were observed in the available coronagraph imagery over the last 24 hours.

Trous coronaux

The equatorial, positive polarity coronal hole (SIDC Coronal Hole 123) is crossing the central meridian since September 30.

Vent solaire

The solar wind conditions (ACE) were enhanced during the last 24 hours, under the ongoing influence of a high-speed stream from the two equatorial, positive polarity coronal holes (SIDC Coronal Holes 128 and 123). The solar wind speed ranged between 730 km/s and 800 km/s. The interplanetary magnetic field values were between 5 nT and 7 nT. The Bz component ranged between -6 nT and 5 nT. The interplanetary magnetic field angle phi was predominantly in the positive sector. Enhanced solar wind conditions are expected over the next 24 hours, mainly under the ongoing influence of the high-speed stream from SIDC Coronal Holes 128 and 123.

Géomagnétisme

Geomagnetic conditions globally during the last 24 hours were initially at active levels (NOAA Kp 4), escalating to minor storm levels (NOAA Kp 5-) between 18:00 UTC and 21:00 UTC on October 02 and between 03:00 UTC and 09:00 UTC on October 03. Geomagnetic conditions locally were mostly at active levels (K Bel 4) during the last 24 hours, escalating to minor storm levels (K Bel 5) between 19:00 UTC and 22:00 UTC on October 02. Mostly active to minor storm conditions (NOAA Kp 4 to 5), with a small chance for isolated moderate storm intervals (NOAA Kp 6), are expected over the next 24 hours, under the ongoing influence of the high-speed stream from SIDC Coronal Holes 128 and 123.

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 the threshold level over the next 24 hours, pending no eruptive activity from SIDC Sunspot Groups 648 and 659 (NOAA Active Regions 4230 and 4238).

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV electron flux measured by GOES 18 was above 1000 pfu threshold during the last 24 hours. The greater than 2 MeV electron flux measured by GOES 19 was mostly above 1000 pfu threshold during the last 24 hours, with short intervals under it between 21:40 UTC on October 02 and 04:30 UTC on October 03. The greater than 2 MeV electron flux is expected to remain above the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at moderate levels and is expected to increase over the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 174, sur la base de 12 stations.

Indices solaires pour 02 Oct 2025

Nombre de Wolf, observé par Catania	188
Flux solaire à 10 cm	167
AK Chambon La Forêt	051
AK Wingst	040
Ap estimé	045
Nombre international de taches solaires estimé	169 - Basé sur 21 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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