Viewing archive of Friday, 13 August 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Aug 13 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
13 Aug 2021	074	010
14 Aug 2021	074	005
15 Aug 2021	075	004

Bulletin

Solar flaring activity was at very low levels. No significant flares have been recorded. Region NOAA 2855, of magnetic type alpha, is rotating on the solar disk. Solar activity is expected to remain at very low levels.

No Earth directed Coronal Mass Ejections (CMEs) were observed in the available coronagraphic imagery.

The greater than 10 MeV proton flux was at background levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, while the 24h electron fluence was at nominal levels over the past 24 hours. Over the next 24 hours they are expected to remain at those levels.

Mixed fields and small level influence from high speed steams associated with extensions of the polar coronal holes are reflected on the solar wind parameters. Over the past 24 hours the solar wind speed decreased further, down to down to 350 km/s until Aug 13 04:28UT, when it started increasing again. Accordingly Bz dropped to -4 nT, from background levels. The total magnetic field strength had values between 1 and 9 nT. The interplanetary magnetic field phi angle was predominantly on the negative sector (directed towards the Sun), switching to positive early Aug 13. Over the next 24 hours, solar wind conditions are expected to remain at about these levels.

Geomagnetic conditions were at quiet to unsettled levels (NOAA Kp and K Dourbes 1-3) over the past 24 hours. Quiet to unsettled conditions are expected over the next 24 hours.

Today's estimated international sunspot number (ISN): 010, based on 24 stations.

Solar indices for 12 Aug 2021

Wolf number Catania	///
10cm solar flux	074
AK Chambon La Forêt	009
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	008 - Based on 30 stations

Noticeable events summary

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

All times in UTC

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