Viewing archive of Sunday, 29 December 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Dec 29 1325 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
29 Dec 2013	138	004
30 Dec 2013	143	007
31 Dec 2013	143	004

Bulletin

There were one M flare and nine C flares on the Sun during the past 24 hours. The M3.1 flare was released by NOAA AR 11936, and peaked at 07:56 UT on December 29. The probability for C flares over the next 48 hours is very high (around 95%) and for M flares around 55%. There is a slight chance for an X flare, especially from AR 11936. The > 10 MeV proton flux as observed by GOES13 started rising near 18:50 UT on December 28. It exceeded the threshold level of 10 pfu around 21:50 UT, and attained a peak value of 29 pfu at 23:15 UT. It went under the 10 pfu threshold again at 7:50 UT on December 29, and is further decreasing. The > 50 MeV and > 100 MeV proton flux have also increased, but have not exceeded the 10 pfu threshold. This proton event is most probably associated with the halo CME first observed by LASCO C2 at 17:36 UT on December 28, which is probably linked to a backsided eruption. A warning condition for further proton storms is issued. Around 13h UT on December 28, the solar wind speed as observed by ACE suddenly increased above its plateau of around 300 km/s, and gradually rose further to a plateau of around 370 km/s. During the past 24 hours, the magnitude of the Interplanetary Magnetic Field varied between about 3 nT and 9 nT. A continuation of nominal solar wind conditions is expected on December 29-31. Geomagnetic activity has been quiet over the past 24 hours (NOAA Kp between 1 and 2). Quiet geomagnetic conditions (K Dourbes < 4) are expected on December 29, 30, and 31, with a slight chance of active conditions (K Dourbes = 4) in the first half of December 30 (in case the Earth suffers a glancing blow from the CME first observed by LASCO C2 at 7:36 UT on December 26).

Today's estimated international sunspot number (ISN): 087, based on 23 stations.

Solar indices for 28 Dec 2013

Wolf number Catania	///
10cm solar flux	135
AK Chambon La Forêt	006
AK Wingst	002
Estimated Ap	002
Estimated international sunspot number	069 - Based on 25 stations

Noticeable events summary

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

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