Affichage des archives de lundi, 26 mai 2025

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 May 26 1232 UTC

Prévisions SIDC

Éruptions solaires

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

Géomagnétisme

Quiet (A<20 and K<4)

Moniteur de Flux de Proton

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

	Flux de 10 cm	Ap
26 May 2025	138	006
27 May 2025	142	006
28 May 2025	144	015

Régions solaires actives et éruptions solaires

Solar flaring activity over the last 24 hours has been moderate, with one M-class flare. The strongest flare was an M8.9 flare (SIDC Flare 4460) peaking on May 25 at 16:30 UTC, which was produced by SIDC Sunspot Group 506 (NOAA Active Region 4098, magnetic type beta-gamma-delta). This is the most complex region on disk and produced most of the flaring activity. SIDC Sunspot Group 508 (NOAA 4099) also produced low level C-class flares. The seven other numbered active regions on the solar disk were quiet. SIDC Sunspot Group 469 (NOAA AR 4100, magnetic type beta), a returning region, has rotated onto the disk over the east limb. The solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected and further M-class flares possible.

Éjection de masse coronale

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

Trous coronaux

The small equatorial, negative polarity coronal hole (returning SIDC Coronal Hole 99) that crossed the central meridian on May 25 is now on the western hemisphere. An extended mid-latitude to equatorial coronal hole (SIDC Coronal Hole 116), also with negative polarity, began to transit the central meridian on May 26. An associated high-speed stream is expected to arrive at Earth from May 29.

Vent solaire

The solar wind conditions reflected a slow solar wind regime. The solar wind speed ranged between 330 km/s to 495 km/s. The interplanetary magnetic field ranged between 2 nT and 11 nT. The Bz component ranged between -9 nT and 9 nT. The interplanetary magnetic field angle phi was mostly in the positive sector. Slow solar wind conditions are expected over the next 24 hours.

Géomagnétisme

Geomagnetic conditions globally and locally were at quiet levels (NOAA Kp 2, K BEL 2) over the past 24 hours. Quiet conditions 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 over the past 24 hours. It is expected generally to remain below this threshold level over the next 24 hours, but a chance of an increase remains due to any high-level flaring activity from SIDC Sunspot Group 506 (NOAA Active Region 4098) as it approaches the west limb.

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV electron flux measured by GOES 18 crossed the 1000 pfu threshold between 17:35 and 23:05 UTC on May 25. The greater than 2 MeV electron flux measured by GOES 19 was just 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 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 : 124, sur la base de 20 stations.

Indices solaires pour 25 May 2025

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	133
AK Chambon La Forêt	010
AK Wingst	///
Ap estimé	009
Nombre international de taches solaires estimé	103 - 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

<< Aller à l'aperçu quotidien