Viewing archive of Friday, 7 September 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 Sep 07 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
07 Sep 2018	067	011
08 Sep 2018	067	010
09 Sep 2018	067	006

Bulletin

Solar activity was at very low levels. The Sun remained spotless. No earth-directed coronal mass ejections (CMEs) were observed in the available coronagraphic imagery. The greater than 10 MeV proton flux was at nominal levels. A trans-equatorial extension of the positive polarity coronal hole (CH) at the Sun's north pole has started its transit of the Central Meridian early on 7 September.

Solar activity is expected to remain at very low levels.

Solar wind was steady at nominal values, until the arrival of the co- rotating interaction region (CIR) and wind stream from the negative polarity CH. The CIR arrived around 19:30UT, with solar wind density increasing from about 5 to 24 particles/cm3 by midnight, and the interplanetary magnetic field changing direction from mostly away to mostly towards the Sun. Solar wind speed started to increase from 02:30UT onwards, reaching a maximum near 510 km/s by 08UT, and is steady since then (DSCOVR). Bz varied between -4 and +4 nT, being mostly positive, and with a strong positive episode near +10 nT from 04UT till 07UT, with little interruption.

Due to the predominately positive Bz, mostly quiet geomagnetic conditions were observed. Quiet to unsettled geomagnetic conditions are expected, with a decreasing chance on an active episode as the CH wind stream is passing by.

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

Solar indices for 06 Sep 2018

Wolf number Catania	000
10cm solar flux	067
AK Chambon La Forêt	010
AK Wingst	005
Estimated Ap	004
Estimated international sunspot number	000 - Based on 26 stations

Noticeable events summary

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

All times in UTC

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