Viewing archive of Saturday, 28 December 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Dec 28 1223 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
28 Dec 2013	133	001
29 Dec 2013	133	001
30 Dec 2013	133	005

Bulletin

There were six C flares on the Sun during the past 24 hours. The brightest one was a C2.3 flare released by NOAA AR 11934, which peaked at 23:36 UT on December 27. Since AR 11934 and 11936 are still showing flux emergence, the probability for C flares over the next 48 hours is high (around 90%) and for M flares around 25%. Over the past 24 hours, the solar wind speed as observed by ACE gradually decreased from about 310 km/s to about 280 km/s. Around 18h UT on December 27, the magnitude of the Interplanetary Magnetic Field dropped suddenly from about 8 nT to about 3 nT. A continuation of nominal solar wind conditions is expected on December 28-30. Geomagnetic activity has been quiet over the past 24 hours (NOAA Kp between 0 and 2). Quiet geomagnetic conditions (K Dourbes < 4) are expected on December 28, 29, and 30, 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): 066, based on 17 stations.

Solar indices for 27 Dec 2013

Wolf number Catania	///
10cm solar flux	131
AK Chambon La Forêt	005
AK Wingst	002
Estimated Ap	002
Estimated international sunspot number	077 - Based on 13 stations

Noticeable events summary

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

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