Tägliches Bulletin zur solaren und geomagnetischen Aktivität des SIDC

Ausgestellt: 2026 Jul 21 1242 UTC

Vorhersage des SIDC

Sonneneruptionen

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

Geomagnetismus

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

Sonnenprotonen

Quiet

	10cm Fluss	Ap
21 Jul 2026	144	028
22 Jul 2026	148	022
23 Jul 2026	152	032

Solaraktive Regionen und Flares

Solar flaring activity was at moderate levels over the past 24 hours with3 M-class flares identified. A total of 6 numbered sunspot groups were identified on the disk over the past 24 hours. The largest flare was a M3.4 flare (SIDC Flare 8220) peaking on July 20 at 22:25 UTC, produced by SIDC Sunspot Group 920 (NOAA Active Region 4493). This region, classified as magnetic type beta-gamma-delta represents the largest and most complex sunspot group on the visible disk, responsible for most of the observed flaring activity, including an M2.5 flare (SIDC Flare 8215) peaking on July 20 at 14:36 UTC and an M1.1 flare (SIDC Flare 8214) peaking on July 20 at 19:20 UTC. SIDC Sunspot Group 919 (NOAA Active Region 4492) currently located at N15E55 is classified as magnetic type beta- gamma, but has produced only isolated low levels of activity. The remaining regions are magnetically simpler and have been quiet. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours with C-class flares expected and chances for further M-class flaring.

Koronaler Massenauswurf

No Earth-directed coronal mass ejections (CMEs) have been identified in the available coronagraph imagery over the past 24 hours.

Koronale Löcher

SIDC Coronal Hole 149 (an equatorial coronal hole with a negative polarity) which first reached the central meridian on July 19 continues to partially reside there. An associated high speed stream arrival is about to arrive at the Earth in the upcoming hours. SIDC Coronal Hole 142 (recurrent mid-to-equatorial latitude coronal hole with a negative polarity) has crossed the central meridian on July 20 and continues to reside there. A high speed-stream related to it could be anticipated at Earth on July 23, most probably mixed with ongoing high speed stream from SIDC 149.

Sonnenwind

Over the past 24 hours the solar wind parameters (as measured by ACE at L1) have registered enhancements most probably precursors of an expected high-speed stream arrival from SIDC Coronal Hole 149. The solar wind speed has increased to 430 km/s. The interplanetary magnetic field (B) was enhanced reaching a maximum magnitude of 17.23 nT with a minimum north- south (Bz) component of - 12.2 nT. The B field phi angle has switched from the positive sector to the negative sector (directed towards the Sun). The solar wind parameters are expected to reflect high speed stream conditions over the next days with an anticipated secondary high-speed stream arrival on July 21 related to SIDC Coronal Hole 142.

Geomagnetismus

The geomagnetic conditions over the past 24 hours have been locally quiet to unsettled and globally have reached active levels as measured by the NOAA Kp index between 09 and 12 UTC on July 21. Predominantly unsettled to minor storm levels are expected over the next 24 hours with chances for isolated moderate storm conditions due to an ongoing high-speed stream arrival related to SIDC coronal hole 149. Further minor to moderate geomagnetic storm might be expected on July 23 with an anticipated high speed stream arrival related to SIDC coronal hole 142.

Protonenflusswerte

Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so over the 24 hours.

Elektronenflüsse im geostationären Orbit

The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 was slowly oscillating around the 1000 pfu threshold over the past 24 hours. It is expected to be below the 1000 pfu threshold over the 24 hours. The 24-hour electron fluence was at the border of nominal to moderate levels and is expected to temporary decrease to nominal levels over the 24 hours.

Die heute international geschätzte Sonnenfleckenanzahl (ISN): 094, basierend auf 24 Stationen.

Solarindizes für den 20 Jul 2026

Wolf-Zahl Catania	///
10cm Solarflux	137
AK Chambon La Forêt	010
AK Wingst	006
Geschätzer Ap-Wert	004
Geschätzte internationale Sonnenfleckenzahl	083 - Basierend auf 32 Stationen

Zusammenfassung auffälliger Ereignisse

Zur Verfügung gestellt vom Solar Influences Data Analysis Center© - SIDC - Verarbeitet von SpaceWeatherLive