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Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Aug 01 1241 UTC

Prévisions SIDC

Éruptions solaires

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

Géomagnétisme

Quiet (A<20 and K<4)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
01 Aug 2025	143	009
02 Aug 2025	141	006
03 Aug 2025	145	004

Régions solaires actives et éruptions solaires

Solar flaring activity was at low levels with low C-class flaring over the past 24 hours. A total of 10 numbered sunspot groups were identified on the visible solar disk, all of them being magnetically simple, classified as magnetic type beta or alpha. The most notable activity was a C2.4 flare (SIDC Flare 4984) with peak time 03:39 UTC on Aug 01, produced by SIDC Sunspot Group 564 (NOAA Active Region 4149) from near the west limb. The newly numbered SIDC Sunspot Group 585 (NOAA Active Region 4167), classified as magnetic type beta, has exhibited significant flux emergence and growth over the past 24 hours, contributing to much of the on-disc flaring activity. Other notable regions which contributed to the C-class flaring are SIDC Sunspot Group 572 (NOAA Active Region 4155) and SIDC Sunspot Group 570 (NOAA Active Region 4153). Both have exhibited further decay. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours, with expected background C-class flaring and 50% chances for M-class flares mostly related to region SIDC Sunspot Group 585.

Éjection de masse coronale

No other Earth-directed coronal mass ejection (CMEs) have been detected in the available coronagraph imagery over the past 24 hours.

Trous coronaux

A long narrow negative-polarity coronal hole (SIDC 122), stretching between equatorial region and mid-north latitudes, is currently crossing the central meridian. A mild high-speed stream related to it might reach the Earth on Aug 04.

Vent solaire

Over the past hours the solar wind parameters as measured by ACE have reflected a mild connection to a high-speed stream from a negative polarity coronal hole. The total interplanetary magnetic field (B) reached a maximum of 9.2 nT with a minimum north-south component, Bz, of -6.8 nT. The solar wind speed varied between 376 km/s and 557 km/s. The B field phi angle remained predominantly in the negative sector (directed towards the Sun). Slightly enhanced solar wind conditions are expected to continue over the next day with a smooth transition towards nominal slow solar wind conditions by the end of Aug 02. Mostly nominal solar wind conditions are expected thereafter until a new possible mild high speed stream arrival on Aug 04.

Géomagnétisme

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Predominantly quiet to unsettled geomagnetic conditions are expected for the next 24 hours with remaining small chances for isolated active periods. Mostly quiet conditions are expected thereafter with next possible active periods on Aug 04.

Niveaux de flux de protons

Over the past 24 hours the greater than 10 MeV GOES proton flux has been at nominal levels and is expected to remain so over the next days.

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV GOES electron flux has exceeded the 1000 pfu threshold over the past 24 hours and is expected to exceed the threshold again in the next 24 hours. The 24-hour electron fluence was at nominal levels and is expected to remain so in the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 137, sur la base de 15 stations.

Indices solaires pour 31 Jul 2025

Nombre de Wolf, observé par Catania	167
Flux solaire à 10 cm	145
AK Chambon La Forêt	017
AK Wingst	013
Ap estimé	012
Nombre international de taches solaires estimé	145 - Basé sur 32 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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