Affichage des archives de jeudi, 17 avril 2025

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 Apr 17 1231 UTC

Prévisions SIDC

Éruptions solaires

M-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
17 Apr 2025	151	011
18 Apr 2025	153	014
19 Apr 2025	155	013

Régions solaires actives et éruptions solaires

Solar flaring activity over the last 24 hours has been low, with few C-class flares only. The strongest flare was a C3.1 flare (SIDC Flare 4144) peaking at 23:54 UTC on April 16, associated with SIDC Sunspot Group 473 (NOAA Active Region 4062, magnetic type beta- gamma). There are currently six numbered active regions on the solar disk. The most complex ones are SIDC Sunspot Group 450 and 473 (NOAA Active Regions 4060 and 4062, both of magnetic type beta-gamma). SIDC Sunspot Group 440 (NOAA Active Region 4061) has decayed into plage. The solar flaring activity is expected to be low to moderate over the next 24 hours, with C-class flares expected and M-class flares probable.

Éjection de masse coronale

A prominence eruption was observed in SDO/AIA 304 data around 00:30 UTC on April 17, near the west limb. Two filament eruptions were observed in SDO/AIA 304 data around 02:00 UTC on April 17, in the northwest and in the southwest quadrant. No associated Coronal Mass Ejection (CME) was observed in the available coronagraph imagery. No other Earth-directed CME was observed in the available coronagraph imagery.

Trous coronaux

A southern, mid-latitude, positive polarity coronal hole (SIDC Coronal Hole 104) is crossing the central meridian. An associated high-speed stream may arrive at Earth starting from the UTC evening of April 19.

Vent solaire

The solar wind conditions (ACE and DSCOVR) were enhanced over the last 24 hours, under the effect of the interplanetary Coronal Mass Ejection (ICME) arrivals, associated with the CMEs that lifted off around 23:00 UTC on April 12 and the partial halo CME that lifted off around 08:30 UTC on April 13. The solar wind speed initially decreased from 550 km/s to 450 km/s and then increased again to around 490 km/s. The interplanetary magnetic field was around 17 nT. The Bz component was negative between 10:50 UTC and 19:40 UTC on April 16, with values around -19 nT. Currently, the solar wind speed is around 480 km/s, the interplanetary magnetic field is around 15 nT and the Bz component has flipped to positive, with values around 12 nT. Further enhancements in the solar wind parameters may be expected over the next 24 hours, due to the arrival of the high-speed stream from SIDC Coronal Hole 105.

Géomagnétisme

Geomagnetic conditions globally reached major storm levels (NOAA Kp 7+) between 12:00 UTC and 15:00 UTC on April 16, escalating to severe storm levels (NOAA Kp 8- ) between 18:00 UTC and 21:00 UTC on April 16. Geomagnetic conditions locally were mostly at minor storm levels (K BEL 5), escalating to moderate storm levels (K BEL 6) between 18:00 and 21:00 UTC on April 16. The geomagnetic storms were the result of the interplanetary Coronal Mass Ejection (ICME) arrivals, with a prolonged Bz period, associated with the CMEs that lifted off on April 12 and April 13. Mostly active conditions, with possible minor storm levels (NOAA Kp 4 to 5, K BEL 4 to 5) are expected globally and locally over the next 24 hours, due to the expected arrival of the high-speed stream from SIDC Coronal Hole 105.

Niveaux de flux de protons

The greater than 10 MeV proton flux was below the threshold level over the past 24 hours. It is expected to remain below the threshold level over the next 24 hours.

Flux d'électrons sur l'orbite géostationnaire

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was below the threshold over the past 24 hours. The greater than 2 MeV electron flux is expected to remain below the 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 : 097, sur la base de 11 stations.

Indices solaires pour 16 Apr 2025

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	148
AK Chambon La Forêt	056
AK Wingst	067
Ap estimé	065
Nombre international de taches solaires estimé	085 - Basé sur 11 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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