Affichage des archives de lundi, 19 mai 2025

Bulletin quotidien sur l'activité solaire et géomagnétique du SIDC

Publié: 2025 May 19 1231 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
19 May 2025	120	013
20 May 2025	122	010
21 May 2025	124	010

Régions solaires actives et éruptions solaires

Solar flaring activity over the last 24 hours has been moderate, with one M-class flare and a few C-class flares. The strongest flare was an M3.2 flare peaking at 08:21 UTC on May 19, from beyond the east limb. There are currently five numbered active regions on the solar disk. The most complex one is SIDC Sunspot Group 496 (NOAA Active Region 4087, magnetic type beta-delta). SIDC Sunspot Group 491 has rotated on disk from the east limb, in the southeast quadrant. The solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected and a small chance for M-class flares.

Éjection de masse coronale

A wide Coronal Mass Ejection (CME), SIDC CME 500, was observed in LASCO/C2 and LASCO/C3 coronagraph imagery starting from 00:24 UTC on May 19, lifting off the northwest quadrant. The CME is most likely associated with a long filament eruption observed in SDO/AIA 304 data around 21:48 UTC on May 18 near the central meridian, in mid-latitude northern hemisphere. A possible glancing blow may arrive at Earth starting from the UTC evening of May 22. No other Earth-directed CMEs were observed in the available coronagraph imagery.

Trous coronaux

The elongated, mid-latitude, positive polarity coronal hole (SIDC Coronal Hole 104) continues to cross the central meridian since May 15.

Vent solaire

The solar wind conditions (ACE and DSCOVR) were enhanced during the past 24 hours, most likely due to influence of the high-speed stream from the southern, positive polarity coronal hole (SIDC Coronal Hole 104). The solar wind speed reached 680 km/s and has gradually decreased to around 530 km/s. The interplanetary magnetic field values reached 10 nT and has gradually decreased to 6 nT. The Bz component ranged between -7 nT and 9 nT. The interplanetary magnetic field angle phi was predominantly in the positive sector. Further enhancements in the solar wind conditions may be expected over the next 24 hours, under the continuous influence of the high-speed stream from the southern, positive polarity coronal hole (SIDC Coronal Hole 104).

Géomagnétisme

Geomagnetic conditions globally reached active levels (NOAA Kp 4) between 15:00 UTC and 21:00 UTC on May 18. Geomagnetic conditions locally were at unsettled levels (K BEL 3), reaching active levels between 18:00 UTC and 19:00 UTC on May 18. Mostly unsettled to active levels, with a small chance for isolated minor storm intervals (NOAA Kp 3 to 5, K BEL 3 to 5), are expected over the next 24 hours, under the continuous influence of the high-speed stream from the southern, positive polarity coronal hole (SIDC Coronal Hole 104).

Niveaux de flux de protons

The greater than 10 MeV proton flux was below the 10 pfu threshold 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 was over the 1000 pfu threshold between 16:20 UTC on May 18 and 00:15 UTC on May 19. The greater than 2 MeV electron flux measured by GOES 19 was mostly below the 1000 pfu threshold over the past 24 hours. The greater than 2 MeV electron flux is expected to be above the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels but is expected to gradually increase over the next 24 hours.

Estimation du nombre international de taches solaires (ISN) pour aujourd'hui : 068, sur la base de 19 stations.

Indices solaires pour 18 May 2025

Nombre de Wolf, observé par Catania	///
Flux solaire à 10 cm	118
AK Chambon La Forêt	034
AK Wingst	026
Ap estimé	026
Nombre international de taches solaires estimé	059 - Basé sur 21 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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