Viewing archive of Monday, 23 August 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Aug 23 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
23 Aug 2021	077	008
24 Aug 2021	078	007
25 Aug 2021	079	010

Bulletin

Solar flaring activity is low, with only few B-class flares reported during last 24 hours. The flaring activity mostly originates from NOAA AR 2859. We expect such a low level of flaring activity to persist in the coming hours. There were few rather narrow and slow CMEs observed during last 24 hours, one associated with the prominence eruption close to southern polar coronal hole and a few associated with the flaring from the NOAA AR 2859 and from the behind of the East solar limb regions. Around midnight of August 22 the eruption of a large filament, situated close to the extension of the northern polar coronal hole (down to 25 degrees) was observed. The filament eruption was associated with the partial halo CME. The faint CME of angular width of about 120 degrees was first observed in the SOHO LASCO C2 field of view at about 07:24 UT today, after the data gap of several hours. Presently only two images of the CME are available. We will report on the additional information when data become available, as this CME is probably Earth-directed.

The greater than 10 MeV proton flux was at background levels in the past 24 hours, and we expect it will remain so in the next 24 hours. The greater than 2 MeV electron flux is bellow the 1000 pfu threshold. The 24h electron fluence is already for several days at normal to low levels and we expect it will stay so in the coming 24 hours.

Earth is presently inside the slow solar wind with velocity of about 300 km/s. The interplanetary magnetic field magnitude is 5 nT. The arrival of the solar wind originating from the extension of the northern polar coronal hole can be expected at Earth in the evening of August 24. During the last 24 hours the geomagnetic conditions were at the quiet to unsettled level and we expect they will stay so in the coming hours.

Today's estimated international sunspot number (ISN): 014, based on 16 stations.

Solar indices for 22 Aug 2021

Wolf number Catania	///
10cm solar flux	077
AK Chambon La Forêt	006
AK Wingst	003
Estimated Ap	002
Estimated international sunspot number	016 - Based on 28 stations

Noticeable events summary

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

All times in UTC

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