Viewing archive of Monday, 11 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 11 1310 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
11 Sep 2017	095	011
12 Sep 2017	094	021
13 Sep 2017	094	008

Bulletin

Strongest flare reported in the last 24 hours was the X8.2 flare which peaked at 16:06 UT, on September 10. This long duration flare, originated from the Catania sunspot group 46 (NOAA AR 2673) which was, at the moment of eruption, already partially behind the west solar limb. The flare was associated with the EIT wave, halo CME and the shock wave which had projected speed of about 2900 km/s. The steep increase of the proton fluxes, with >10 MeV, > 50 MeV as well as >100MeV, associated with the X8.2 flare was observed yesterday. The proton flux levels are slowly decreasing, but they are presently still above the event threshold.The recently arrived data indicate that the arrival of the CME-driven shock wave, associated with the X-class flare, might be expected tomorrow morning (probably around 08:00 UT). The Catania sunspot group 46 (NOAA AR 2673), which was the source of the majority of the flaring activity during last few days, has rotated behind the west solar limb. Therefore, we expect solar activity to be low, with at most C-class flares.

The solar wind speed remains to be rather high, amounting about 600 km/s, and the interplanetary magnetic field magnitude is about 4 nT. The fast solar wind, associated with the low latitude coronal hole in the northern hemisphere which reached the central meridian in the mid-day yesterday, is expecting to arrive at the Earth on September 13. Geomagnetic conditions are presently quiet to unsettled. We expect active conditions within next 24 hours due to arrival of the CME-driven shock wave.

Today's estimated international sunspot number (ISN): 033, based on 19 stations.

Solar indices for 10 Sep 2017

Wolf number Catania	///
10cm solar flux	100
AK Chambon La Forêt	017
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	046 - Based on 23 stations

Noticeable events summary

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

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