:Issued: 2011 Oct 25 0942 UTC
:Product: documentation at http://www.sidc.be/products/bul
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# SIDC Weekly bulletin on Solar and Geomagnetic activity #
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WEEK 564 from 2011 Oct 17
SOLAR ACTIVITY
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Solar activity was moderate during the week with
3 M class flares, which occurred on Oct. 20, 21
and 22. The M1.6 flare of Oct. 20 (0325 UT peak time)
was partially occulted as it occurred behind the
west limb. The M1.3 flare of Oct. 21 (1300 UT peak
time) took place in NOAA AR 1319. Finally, a M1.3 long
duration event occurred in NOAA AR 1314 on Oct.
22 (1110 UT peak time), close to the west limb.
This last event was associated with a >10 MeV
proton flux enhancement that barely reached
the threshold for a proper proton event on Oct. 23.
A filament eruption occurred on Oct. 22
around 0200 UT, followed by a CME potentially Earth
directed.
GEOMAGNETIC ACTIVITY
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The geomagnetic conditions were very low during the week.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Oct 17 184 116 153 006 B9.8 0 0
2011 Oct 18 167 102 147 004 B8.6 0 0
2011 Oct 19 171 095 147 006 B7.8 0 0
2011 Oct 20 212 122 159 006 B8.6 1 0
2011 Oct 21 /// 135 168 004 B9.9 1 0
2011 Oct 22 /// 116 164 002 B9.3 1 0
2011 Oct 23 /// 083 156 003 B7.6 0 0
# RC : Sunspot index (Wolf Number) from Catania Observatory (Italy)
# EISN : Estimated International Sunspot Number
# 10cm : 10.7 cm radioflux (DRAO, Canada)
# Ak : Ak Index Wingst (Germany)
# BKG : Background GOES X-ray level (NOAA, USA)
# M,X : Number of X-ray flares in M and X class, see below (NOAA, USA)
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NOTICEABLE EVENTS
DAY BEGIN MAX END LOC XRAY OP TENCM TYPE Cat NOAA NOTE
20 0310 0325 0344 M1.6 CTM/1,III/1,VI/1 partially occulted event on the west limb
21 1253 1300 1308 M1.3 55 V/2,II/1,IV/1 1319
22 1000 1110 1309 N25W77 M1.3 SF CTM/1 1314
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# Solar Influences Data analysis Center - RWC Belgium #
# Royal Observatory of Belgium #
# Fax : 32 (0) 2 373 0 224 #
# Tel.: 32 (0) 2 373 0 491 #
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