Viewing archive of Friday, 30 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 30 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
30 Jul 2021	075	004
31 Jul 2021	076	005
01 Aug 2021	078	005

Bulletin

The visible solar disc is spotless and the X-ray flux is below B-level. The solar activity is expected to remain at low levels over the next 24 hours.

No Earth directed Coronal Mass Ejection (CME) has been detected in the available coronagraph imagery.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux was below the 1000 pfu threshold in the past 24 hours. The greater than 2 MeV electron flux may slightly increase during the next 24 hours due to the high-speed streams. The 24h electron fluence was at normal levels in the last 24 hours and may also slightly increase for the next 24 hours.

The solar wind parameters (as observed by ACE and DSCOVR) show some indications of a slow return towards an ambient background and slow solar wind speed regime. Solar wind speed decreased from 570 to near about 450 km/s. Total interplanetary magnetic field strength remained below 7 nT. The Bz component underwent only weak deviations (between -4 nT and +4 nT), with no prolonged period of southward direction. The solar wind conditions are expected to continue it slow returned toward a slow solar wind speed regime. The solar wind may be temporarily slightly enhanced later on July 30 due to some possible effect of the arrival of the coronal mass ejection observed on July 27 at 03:24 UTC (with a projected speed of 388 km/s).

The geomagnetic conditions were quiet over the past 24 hours. The conditions are expected to remain mostly quiet as the Earth is expected to remain in the mostly slow solar wind speed regime for the next 24 hours.

Today's estimated international sunspot number (ISN): 000, based on 24 stations.

Solar indices for 29 Jul 2021

Wolf number Catania	013
10cm solar flux	076
AK Chambon La Forêt	013
AK Wingst	012
Estimated Ap	011
Estimated international sunspot number	002 - Based on 33 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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