Viewing archive of Sunday, 8 December 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Dec 08 1250 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
08 Dec 2013	157	024
09 Dec 2013	157	008
10 Dec 2013	157	014

Bulletin

The X-ray curve is situated near the top/bottom of the B/C-level. C-flares are very likely, the probability for M-flares is around 20%. The December 7 M1.2 flare (07:29UT peak time) from NOAA AR 1909 was associated with a CME. CACTus determined it as a (partial) halo CME with a speed around 900 km/s. The bulk of the plasma is ejected under the ecliptic plane. The side of the CME may impact the Earth. This glancing blow can possibly arrive late December 9, early December 10 and may result in geomagnetic disturbances. Late December 7, a co-rotating interaction region (CIR) arrived. The density increased gradually together with the magnetic field. The z-component fluctuated strongly, even to -25nT which resulted in a planetary K of 6 and 5 and local K Dourbes of 5 and 4 early December 8. Following the density increase and slow decrease, the solar wind speed increased gradually. The CIR and fast solar wind is possibly linked with the coronal hole which reached the central meridian on December 3. A shock is visible on ACE data on December 8, 7:30UT: the solar wind speed increased from 500 km/s to around 650 km/s, the temperature, density and magnetic field dropped. This fast reverse shock is possibly linked with the filament eruption of December 5. The geomagnetic impact will be limited and smaller compared to the CIR because of the drop in magnetic field strength. Bz rotated from negative (-5nTToday's estimated international sunspot number (ISN): 065, based on 10 stations.

Solar indices for 07 Dec 2013

Wolf number Catania	///
10cm solar flux	157
AK Chambon La Forêt	026
AK Wingst	008
Estimated Ap	007
Estimated international sunspot number	062 - Based on 14 stations

Noticeable events summary

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

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