Viewing archive of Saturday, 31 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 31 1233 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
31 Jul 2021	076	009
01 Aug 2021	076	007
02 Aug 2021	078	007

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 and is expected to remain so during the next 24 hours. The 24h electron fluence was at normal levels in the last 24 hours and is expected to stay at normal levels 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 about 500 km/s to 440 km/s. Total interplanetary magnetic field strength remained below 6.5 nT. The Bz component underwent only weak deviations between -2.5nT and +5.7 nT. The solar wind conditions are expected to continue it slow returned towards a slow solar wind speed regime. The solar wind may be temporarily slightly enhanced later on July 31 or the day after due to some possible effect of the arrival of the coronal mass ejection observed on July 28 at 10:36 UTC (with a projected speed of 400 km/s).

The geomagnetic conditions were quiet over the past 24 hours with some short periods of unsettled condition observed by the local station Dourbes (K-Dourbes = 2-3). 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): 001, based on 16 stations.

Solar indices for 30 Jul 2021

Wolf number Catania	///
10cm solar flux	076
AK Chambon La Forêt	014
AK Wingst	010
Estimated Ap	009
Estimated international sunspot number	000 - Based on 37 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page