:Issued: 2011 Jun 20 1621 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 546 from 2011 Jun 13
SOLAR ACTIVITY
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Solar activity was low over the whole week, with only a few C flares and
one M1.3 flare on June 14.The GOES X-ray flux remained at B level. The
main active regions on the solar disk were Catania #07 (NOAA11234) and #10
(NOAA11236), both D-type regions. The later spawned the only M flare and
acquired a beta-gamma configuration late in the week, but both regions had
a limited growth and were declining at the end of the week.
The main event of the week was a large filament eruption in the South-East
quadrant on June 14 around 8:00UT. This produced a semi-halo CME that was
only weakly geoeffective.
On June 14, the solar wind speed rose to a maximum of 550km/s due to a
weak solar wind stream from a small coronal hole. It then returned to a
background speed of about 430 km/s. On June 17 around 2:40UT, a shock
reaching briefly 550km/s hit the Earth, but there was no associated
magnetic cloud. This brief event marked the glancing blow of the June 14
CME.
GEOMAGNETIC ACTIVITY
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Geomagnetic activity was unsettled on June 13 and 14 due to the enhanced
solar wind. Then, it remained quiet to unsettled until June 17, when the
CME arrival caused unsettled conditions during a few hours. The Earth
magnetosphere was again quiet over the last two days of the week.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Jun 13 016 010 87 013 B2.6 0 0
2011 Jun 14 050 024 99 012 B2.4 1 0
2011 Jun 15 054 031 102 008 B2.4 0 0
2011 Jun 16 070 039 103 007 B3.0 0 0
2011 Jun 17 068 040 104 012 B2.9 0 0
2011 Jun 18 092 040 99 006 B2.3 0 0
2011 Jun 19 /// 035 99 005 B2.0 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
14 2136 2147 2210 N15E77 M1.3 SF 10 1236
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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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