Affichage des archives de mercredi, 2 décembre 2020

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2020 Dec 02 1245 UTC

Prévisions SIDC

Éruptions solaires

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

Géomagnétisme

Minor storm expected (A>=30 or K=5)

Moniteur de Flux de Proton

Quiet

	Flux de 10 cm	Ap
02 Dec 2020	100	006
03 Dec 2020	098	010
04 Dec 2020	096	029

Bulletin

Solar activity was relatively quiet, with only a single C flare peaking at C1.4 magnitude at 23:20UT from NOAA region 2786. There are 3 regions on disk of which 2 are classified as beta regions. The largest is NOAA AR 2786, already on disk for a while, and there is the new region NOAA AR 2790 that just rotated into view. Both appear relatively inactive and stable. Further C flares can be expected. An isolated M flare is possible but has a low probability (10%).

As reported yesterday, the C1 flare peaking at 7:21UT December 1 originating from NOAA AR 2787 was associated with a dimming and EUV wave and an associated CME visible in SoHO/LASCO from 7:12UT. While the core of the CME is clearly not directed directly Earthward, a shock signature can be seen expanding over the South and there are also faint signatures over the North. Hence the CME could potentially be claimed to be classified as partial Halo. There is a chance for a glancing blow at Earth from this CME. If it occurs, it is expected from the morning of December 4. No other Earth directed CMEs have been observed in coronagraph data.

The greater than 10MeV proton flux seemed to decay but ultimately remained enhanced reaching to 6pfu. It is not expected to rise much further although that can not be excluded. The greater than 2MeV electron flux did not exceed the 1000 pfu alert threshold during its diurnal maximum. The 24h electron fluence was at moderate levels and is expected to be at normal to moderate levels over the next 24 hours. An increasing trend is expected following the recent Solar wind enhancements.

Solar wind conditions remained enhanced with Solar wind speed above 500 km/s for most of the period. But after 7UT, solar wind speed came to lie in the more nominal 400-450 km/s regime. The interplanetary magnetic field magnitude was around a nominal 5nT with a variable and unremarkable North- South orientation. The phi angle was mostly in the negative sector (towards the Sun). There were no signs of possible perturbations associated to the November 29 CME. Essentially nominal Solar wind conditions are expected with a slight chance for perturbations from the morning of December 4 onwards associated to the December 1 CME.

Geomagnetic conditions were quiet (both local K Dourbes and NOAA Kp 0-2). Geomagnetic conditions are expected to be quiet over the next 24 hours, followed by possibly active conditions or minor geomagnetic storming should a glancing blow from the December 1 CME occur.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 044, sur la base de 04 stations.

Indices solaires pour 01 Dec 2020

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	104
AK Chambon La Forêt	005
AK Wingst	002
Ap estimé	002
Nombre international de taches solaires estimé	046 - Basé sur 17 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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