Affichage des archives de vendredi, 17 septembre 2021

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2021 Sep 17 1230 UTC

Prévisions SIDC

Éruptions solaires

Quiet conditions (<50% probability of C-class flares)

Géomagnétisme

Active conditions expected (A>=20 or K=4)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
17 Sep 2021	073	012
18 Sep 2021	072	008
19 Sep 2021	075	003

Bulletin

The solar activity was at low levels with only one detection of a C3.5 flare during the last 24 hours. There are currently no Active Regions (AR) visible from Earth, however the C-class activity came at 04:51 UT from an AR expected to soon turn into view. NOAA plage 2870 is also present on the front side of the solar disk, but did not produce any noticeable activity. For the next 24 hours more C-class activity and even an M-class flare is possible from the same AR, although it is difficult to provide a reliable estimation as its magnetic complexity is currently unknown.

No Earth-directed CMEs were detected in the available coronagraph imagery over the past 24 hours. A partial halo CME visible in SOHO/LASCO-C2 images starting from today 04:28 UT, is back-sided and not expected to be geo- effective.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2MeV electron flux was below the 1000 pfu threshold and is expected to remain so in the next 24 hours. The 24h fluence for the greater than 2MeV electron flux was at nominal levels and is expected to remain so in the next 24 hours.

The Solar Wind (SW) parameters show the arrival at 01:30 UT of the CME observed on 14 Sep and predicted to arrive on 18 Sep. The SW speed varied between 290 and 410 km/s during the last 24 hours. The total magnetic field (Btot) varied between 2.7 and 8.7 nT, while the Bz component between -6.8 and 2.8 nT in the last 24 hours. The interplanetary magnetic field phi angle was in the positive sector (directed away from the Sun) until the arrival of the ICME, and varied almost equally between the two sectors since. The SW are expected to return to a typical slow solar wind regime in the next 24 hours as the ICME appears to be small and relatively slow.

Geomagnetic conditions were globally quiet to active (NOAA Kp 1-4) and locally quiet (K Dourbes 1-2). For the next 24 hours the geomagnetic conditions are expected to become active, due to the arrival of the CME detected on 14 Sep.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 000, sur la base de 17 stations.

Indices solaires pour 16 Sep 2021

Nombre de Wolf, observé par Catania	000
Flux solaire à 10 cm	073
AK Chambon La Forêt	010
AK Wingst	004
Ap estimé	002
Nombre international de taches solaires estimé	000 - 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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