Viewing archive of Saturday, 13 September 2014

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2014 Sep 13 1234 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
13 Sep 2014	156	022
14 Sep 2014	160	008
15 Sep 2014	162	005

Bulletin

There are currently 6 sunspot groups visible on the solar disk. The most prominent groups, NOAA 2157 and 2158, are decaying. These groups still have spots of opposite magnetic polarity close to each other. A total of 7 C-class flares were recorded. The strongest flare of the period was a C3.3 peaking at 20:12UT. It occurred in an unnumbered sunspot region close to the southwest limb. NOAA 2166 is a small group embedded in a large plage area in the northeast quadrant, and produced only a C1 flare. Two filament eruptions were observed around 23:50UT and 03:40UT, but the associated CMEs were not Earth directed. Other CMEs, first observed by SOHO/LASCO on 12 September at 18:24UT and 21:48UT, were related to backside events and will not affect Earth. The proton event related to the X1 flare ended at 23:10UT. Further C-class flaring is expected, with a chance on an M-class flare. The arrival of the halo CME related to the X1 flare from 10 September was observed by SOHO/CELIAS as a shock in the solar wind on 12 September at 15:27UT. Wind speed increased abruptly from 430 to 670 km/s, and further increased to a maximum of nearly 800 km/s around 22:00UT. Bz was oriented southward between 20:30 and 22:00UT with maximum values near -17nT, then abruptly turned northward to steady values around +20 nT. The period between 21:00UT and 24:00UT was geomagnetically the most intense, with Kp reaching 7 (strong geomagnetic storm), and local K-indices at Dourbes and Potzdam reaching 6 (moderate storming). Geomagnetic conditions then quieted down, with currently unsettled to active conditions observed. Quiet to unsettled geomagnetic conditions are expected, with locally a brief active period possible in the aftermath of yesterday's geomagnetic storm.

Today's estimated international sunspot number (ISN): 082, based on 13 stations.

Solar indices for 12 Sep 2014

Wolf number Catania	///
10cm solar flux	152
AK Chambon La Forêt	047
AK Wingst	039
Estimated Ap	043
Estimated international sunspot number	091 - Based on 20 stations

Noticeable events summary

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

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