Viewing archive of Sunday, 7 September 2014

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2014 Sep 07 1329 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
07 Sep 2014	160	013
08 Sep 2014	162	009
09 Sep 2014	163	005

Bulletin

Ten sunspot groups are reported by NOAA today. NOAA ARs 2152, 2157, and 2158 have respectively beta-gamma, beta-gamma-delta, and beta- delta configurations of the photospheric magnetic field. The strongest flare of the past 24 hours was the M1.1 flare peaking yesterday at 17:09 UT in the NOAA AR 2157. This flare was not associated with a CME. The solar X-ray background flux is around the C1 level, so we expect flaring activity on the M-level, most probably from the NOAA ARs 2157, 2158, and 2159. Yesterday's C8.0 flare in the NOAA AR 2157 was associated with a partial halo CME that had the speed around 350 km/s (according to the CACTus software) and angular width around 140 degrees. The bulk of the CME material was directed significantly eastward of the Sun-Earth line, so we expect at most a glancing blow of the corresponding ICME at the Earth on September 10, most probably without significant geomagnetic consequences. The solar proton flux, although starting a slow decrease, is just below the SEP event threshold, so we maintain the warning condition for a proton event. The Earth is still inside an ICME probably produced by the partial halo CME observed on the Sun on September 2. The interplanetary magnetic field (IMF) magnitude is currently around 8-9 nT, and the solar wind speed is around 350 km/s. Despite some intervals of southward IMF, the geomagnetic conditions remained quiet (only one interval of K = 4 was reported by IZMIRAN) due to low solar wind speed and low magnitude of the southward IMF. We expect quiet geomagnetic conditions to continue, with isolated intervals of active conditions possible but not very likely.

Today's estimated international sunspot number (ISN): 110, based on 16 stations.

Solar indices for 06 Sep 2014

Wolf number Catania	///
10cm solar flux	157
AK Chambon La Forêt	019
AK Wingst	013
Estimated Ap	011
Estimated international sunspot number	096 - Based on 15 stations

Noticeable events summary

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

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