Affichage des archives de samedi, 23 septembre 2017

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2017 Sep 23 1234 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
23 Sep 2017	076	010
24 Sep 2017	079	022
25 Sep 2017	081	007

Bulletin

Over the past 24 hours the solar activity was very low, only a small B-class flare was recorded. Catania sunspot groups 56 (NOAA active regions 2681) remained stable showing no flaring activity. Catania sunspot group 55 (NOAA active region 2680) is currently turning over the west solar limb. The top of the loops from the returning region Catania sunspot group 46 (NOAA active region 2673), from which a B3.0-class flare (Sept 23 at 06:03 UT) is attributed, is now visible at the east solar limb. We expect the solar activity to increase due to this returning region with C-class flares. As this region was very active with several X-class flares during the previous solar rotation, we cannot exclude the possibility of M to X-class flares to occur. Once the foot-points of the loops will be visible, a better estimation of its magnetic complexity will be made and we will be able to better estimate the probability of flaring activity.

No Earth directed CMEs have been observed and the solar protons remained at background level over the past 24 hours.

The Earth remained inside a slow solar wind flow with de speed lower than 400 Km/s. The interplanetary magnetic field magnitude remained below 6 nT and the Bz component fluctuated between -4 and 4 nT being mainly negative. The associated fast solar wind to the small equatorial coronal hole that has crossed the central meridian on Sept 20 is expected to arrive at Earth today around midnight UT time.

Geomagnetic conditions were mostly quiet to unsettled with Kp (NOAA) and local K (Dourbes) indexes ranging between 1-2 and 0-3 respectively. While the solar wind remained in its nominal condition, the local K (Dourbs) sowed an unexpected short duration maximum (K=4) at 22:00 UT due to the Bz components being mostly negative. The geomagnetic conditions are expected to remain quiet to unsettled until Sept 23 when the fast solar will reach Earth.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 012, sur la base de 21 stations.

Indices solaires pour 22 Sep 2017

Nombre de Wolf, observé par Catania	022
Flux solaire à 10 cm	078
AK Chambon La Forêt	012
AK Wingst	008
Ap estimé	006
Nombre international de taches solaires estimé	018 - Basé sur 29 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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