Viewing archive of Friday, 22 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 22 1236 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
22 Sep 2017	067	004
23 Sep 2017	076	016
24 Sep 2017	079	028

Bulletin

Over the past 24 hours the solar activity was very low: no flare has been recorded. Catania sunspot groups 55 and 56 (NOAA active regions 2680 and 2681) are stable and are unlikely to produce any strong flaring activity. Catania sunspot group 55 (NOAA active region 2680) will soon turn over the east solar limb. The top of the loops from the returning region Catania sunspot group 46 (NOAA active region 2673), which was very active in the previous rotation, will start to be seen at the west limb tomorrow, on Sept 23. We expect the solar activity to remain low until the return of Catania sunspot group 46 (NOAA active region 2673). Then we expect the activity to increase with C to M-class flare.

No Earth directed CMEs have been observed and the solar protons remained at background level over the past 24 hours.

The Earth remains inside a slow (about 400 Km/s) solar wind flow. The interplanetary magnetic field magnitude remained below 6 nT and the Bz component fluctuated between -4 and 4 nT. The associated fast solar wind to the small equatorial coronal hole that has crossed the central meridian on Sept 20 is expected to arrive at Earth on Sept 23 late afternoon.

Geomagnetic conditions were quiet to unsettled with Kp (NOAA) and local K (Dourbes) indexes ranging between 0-3 and 0-2 respectively. The geomagnetic conditions are expected to remain quiet until Sept 23 when the fast solar will reach Earth.

Today's estimated international sunspot number (ISN): 020, based on 17 stations.

Solar indices for 21 Sep 2017

Wolf number Catania	023
10cm solar flux	073
AK Chambon La Forêt	013
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	022 - Based on 32 stations

Noticeable events summary

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

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