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Daily bulletin on solar and geomagnetic activity from the SIDC

Emesso: 2014 Feb 12 1253 UTC

SIDC Forecast

Brillamenti solari

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

Geomagnetism

Quiet (A<20 and K<4)

Protoni solari

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

	10cm flux	Ap
12 Feb 2014	172	012
13 Feb 2014	176	009
14 Feb 2014	178	010

Bulletin

The solar flaring activity is increasing during past 24 hours with majority of activity originating from the Catania sunspot group 36 (NOAA AR 1974). The strongest of four reported M-class flares was observed this morning. The M3.7 flare peaked at 04:25 UT on February 12 and was associated with an EIT wave, coronal dimming and full halo CME first seen in the SOHO LASCO C2 field of view at 05:48 UT. From the currently available data we conclude that the CME is Earth directed. The impulsive M1.7 flare which peaked at 03:31 UT on February 11 was accompanied by an EIT wave, coronal dimmings and type II radio burst (indicating the shock speed of about 870 km/s). The flare originated from the Catania sunspot group 36 (NOAA AR 1974) currently situated at the center of the solar disc. The full halo CME associated with this flare was first seen in the SOHO LASCO C2 field of view at 04:12 UT. The expected arrival of this halo CME is late February 16. We do not expect strongly disturbed geomagnetic conditions (K index maximum 4) due to its faint structure and slow speed of 300 km/s (as reported by the CACTUS software). A partial halo CME detected in the SOHO/LASCO C2 field of view at 09:24 UT on February 11 had angular width of about 200 degrees, and speed around 320 km/s (as reported by the CACTUS software). The CME was associated with an eruption of a filament situated between the Catania sunspot group 35 (NOAA AR 1973) and newly emerged, unnumbered active region situated on the west from the Catania sunspot group 35. The eruption was accompanied by coronal dimmings and a post-eruption arcade observed by SDO/AIA. The bulk of the CME mass was directed northward of the Sun-Earth line, so we expect the arrival of only a CME-driven shock at the Earth, probably on February 16. It may result in active to minor storm geomagnetic conditions. A partial halo CME detected by SOHO/LASCO C2 field of view at 14:00 UT on February11 was associated with the flare at about W120 as seen from the Earth. This was a back side event and it will not arrive at the Earth. The M1.8 flare observed on February 11, originated from the Catania sunspot group 36 (NOAA AR 1974). The flare peaked at 16:51 UT on February 11 was accompanied by an EIT wave and small coronal dimming. The currently available data show the possibly associated partial halo CME first seen in the SOHO LASCO C2 field of view at 18:00 UT. The CME might be Earth directed. A full halo CME detected by SOHO/LASCO on February 11, had first appeared in the LASCO C2 field of view at 19:24 UT. The CME propagated with the speed of about 500 km/s (as reported by the CACTUS software) was most probably associated with the flare at the back side of the Sun, as seen from the Earth. Since this was a back side event it will not arrive at the Earth. The Catania sunspot group 36 (NOAA AR 1974) is growing fast and currently has beta-gamma-delta configuration of its photospheric magnetic field. Therefore, we expect C-class and M-class flares, and possibly also an isolated X-class flare. Due to position of the Catania sunspot group 36 (NOAA AR 1974), at center of the solar disc, a major CME from this active region may lead to a proton event, so we issue the warning condition for a proton event. Earth is currently inside a slow solar wind with the speed of about 450 km/s. The interplanetary magnetic field is stable with the magnitude of 5 nT. We expect quiet geomagnetic conditions in the coming hours.

Today's estimated international sunspot number (ISN): 117, based on 15 stations.

Solar indices for 11 Feb 2014

Wolf number Catania	///
10cm solar flux	172
AK Chambon La Forêt	016
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	116 - Based on 14 stations

Noticeable events summary

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

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