:Issued: 2011 Mar 29 1414 UTC
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity #
#--------------------------------------------------------------------#
WEEK 534 from 2011 Mar 21
SOLAR ACTIVITY
--------------
The proton flux was elevated on Mar 21 and 22. The curve passed slightly and for a very short time the proton event threshold.
The initial increase was probably linked with a back sided CME of Mar 21, 02:54UT. The Earth is magnetically connected with the source site behind the Sun. The Parker spiral has bended magnetic field lines that guide the electrically charged protons. The Earth is near such field lines along which these protons travel. This is a rare but non unprecedented event.
That same day, a long duration C-flare took place. The source region was Cat 35/AR 1176. A long duration event is an indication of an associated CME.
Since the group was at that moment located near the very east of the solar disk, the CME was not Earth directed.
This active region, 1176 had a rather complex magnetic structure: beta-gamma and was responsible for almost all flaring activity further this week. This group exerted three moderate M-flares on Mar 23-24-25, one a day.
None of the CME's was Earth directed, except for a very slow plasma structure that left the Sun on Mar 25. Since it was very slow, it is probably overtaken by the ambient solar wind.
GEOMAGNETIC ACTIVITY
--------------------
Mar 22-23, we had unsettled conditions probably induced by a small North-South
oriented coronal hole.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Mar 21 026 015 101 008 B3.8 0 0
2011 Mar 22 061 027 100 009 B4.5 0 0
2011 Mar 23 054 025 105 015 B3.3 1 0
2011 Mar 24 073 036 108 004 B3.2 1 0
2011 Mar 25 127 065 113 004 B4.0 1 0
2011 Mar 26 114 063 115 001 B4.3 0 0
2011 Mar 27 /// 076 117 002 B3.4 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
23 0203 0217 0224 S18E70 M1.4 III/2 35 1176
24 1201 1207 1211 S16E43 M1.0 1F V/2 35 1176
25 2308 2322 2330 S12E26 M1.0 170 II/1,IV/1 35 1176
#--------------------------------------------------------------------#
# 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 #
#--------------------------------------------------------------------#
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity #
#--------------------------------------------------------------------#
WEEK 534 from 2011 Mar 21
SOLAR ACTIVITY
--------------
The proton flux was elevated on Mar 21 and 22. The curve passed slightly and for a very short time the proton event threshold.
The initial increase was probably linked with a back sided CME of Mar 21, 02:54UT. The Earth is magnetically connected with the source site behind the Sun. The Parker spiral has bended magnetic field lines that guide the electrically charged protons. The Earth is near such field lines along which these protons travel. This is a rare but non unprecedented event.
That same day, a long duration C-flare took place. The source region was Cat 35/AR 1176. A long duration event is an indication of an associated CME.
Since the group was at that moment located near the very east of the solar disk, the CME was not Earth directed.
This active region, 1176 had a rather complex magnetic structure: beta-gamma and was responsible for almost all flaring activity further this week. This group exerted three moderate M-flares on Mar 23-24-25, one a day.
None of the CME's was Earth directed, except for a very slow plasma structure that left the Sun on Mar 25. Since it was very slow, it is probably overtaken by the ambient solar wind.
GEOMAGNETIC ACTIVITY
--------------------
Mar 22-23, we had unsettled conditions probably induced by a small North-South
oriented coronal hole.
---------------------------------------------------------------------------
DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Mar 21 026 015 101 008 B3.8 0 0
2011 Mar 22 061 027 100 009 B4.5 0 0
2011 Mar 23 054 025 105 015 B3.3 1 0
2011 Mar 24 073 036 108 004 B3.2 1 0
2011 Mar 25 127 065 113 004 B4.0 1 0
2011 Mar 26 114 063 115 001 B4.3 0 0
2011 Mar 27 /// 076 117 002 B3.4 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)
---------------------------------------------------------------------------
NOTICEABLE EVENTS
DAY BEGIN MAX END LOC XRAY OP TENCM TYPE Cat NOAA NOTE
23 0203 0217 0224 S18E70 M1.4 III/2 35 1176
24 1201 1207 1211 S16E43 M1.0 1F V/2 35 1176
25 2308 2322 2330 S12E26 M1.0 170 II/1,IV/1 35 1176
#--------------------------------------------------------------------#
# 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 #
#--------------------------------------------------------------------#
