Affichage des archives de vendredi, 23 avril 2021

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2021 Apr 23 1230 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
23 Apr 2021	080	010
24 Apr 2021	081	008
25 Apr 2021	080	011

Bulletin

Numerous B-class and C-class flares were reported during last 24 hours. All the flaring activity originated from the two sunspot groups Catania groups 86 and 87 (NOAA AR 2817 and NOAA AR 2816). Presently Catania sunspot group 86 (NOAA AR 2817) is rotating over the West solar limb, which will somewhat decrease the reported flaring activity. However, we can still expect B-class and C-class flares in the coming hours, originating mostly from Catania sunspot group 87 (NOAA AR 2816). M-class flares are possible but not very probable. Faint and slow partial halo CME (reported yesterday), was first seen in the SOHO LASCO C2 field of view at about 06:12 UT on April 22. The CME had angular width of about 160 degrees and projected line of the sight speed of about 450 km/s (as reported by CACTUS software). The CME was Earth directed and we might expect its arrival late evening on April 25. There were no other Earth directed CMEs during last 24 hours. During last 24 hours the proton flux levels remained at background level.

The greater than 2MeV electron flux is still above the 1000 pfu threshold, and it is expected to remain so in the coming 24 hours. The 24h electron fluence is at moderate to high level and is likely it will stay so in the next 24 hours.

Earth is presently inside the slow solar wind (speed of about 390 km/s), and the interplanetary magnetic field magnitude is 4 nT. The solar wind originating from the small, negative polarity equatorial coronal hole (reached central meridian in the morning of April 20), can be expected at Earth in the coming hours. During last 24 hours geomagnetic conditions were quiet. We expect quiet to unsettled geomagnetic conditions in the coming hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 033, sur la base de 27 stations.

Indices solaires pour 22 Apr 2021

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	084
AK Chambon La Forêt	014
AK Wingst	006
Ap estimé	005
Nombre international de taches solaires estimé	043 - Basé sur 36 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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