Viewing archive of Thursday, 25 January 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 Jan 25 1230 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
25 Jan 2018	070	009
26 Jan 2018	069	007
27 Jan 2018	069	010

Bulletin

Solar activity was at very low levels. The Sun is spotless. No earth-directed coronal mass ejections (CMEs) were observed in available coronagraphic imagery. The greater than 10 MeV proton flux was at nominal levels.

Solar activity is expected to remain at very low levels.

Earth crossed a fold in the Heliospheric Current Sheet (HCS) on 24 January. The interplanetary magnetic field (IMF) was mostly directed away from the Sun from 02UT until about 20UT, after which it switched to a mostly towards orientation. Solar wind speed gradually increased from an initial 350 km/s to 400 km/s around 20UT, after which it remained steady in the range of 400-420 km/s. Bz oscillated between -9 and +8 nT, with a longer stretch of mostly negative values between 20-01UT (DSCOVR). A small negative equatorial coronal hole (CH) and the extension of a positive polar CH are transiting the central meridian.

The geomagnetic field was at quiet to unsettled conditions, with an active episode recorded during the 21-24UT interval. Mostly quiet to unsettled conditions with a chance on an active episode are expected for the coming days, in view of possible further crossings of the HCS and the potential arrival of the wind streams associated with the aforementioned CHs around 27 and 28 January.

Today's estimated international sunspot number (ISN): 000, based on 05 stations.

Solar indices for 24 Jan 2018

Wolf number Catania	000
10cm solar flux	070
AK Chambon La Forêt	019
AK Wingst	011
Estimated Ap	010
Estimated international sunspot number	000 - Based on 19 stations

Noticeable events summary

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

All times in UTC

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