:Issued: 2011 Sep 26 1515 UTC
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity #
#--------------------------------------------------------------------#
WEEK 560 from 2011 Sep 19
SOLAR ACTIVITY
--------
The past week featured strong solar activity with continuous flaring at C-class level, 19 M-flares and 2 X-flares. During the course of the the week, the GOES X-ray background level increased from B to high C-level. The most prominent active regions on the solar disk were Catania 72 and 74 (NOAA AR 1295 and 1296), Catania 80 (NOAA AR 1301, Catania 82 (NOAA AR 1302) and Catania 83 (NOAA AR 1303).
The main events produced by Cat 74 were a C6.2 flare peaking at 07:37 on Monday Sept. 19, associated with type III radio bursts in Humain, and a C9.5 flare with peak time 05:13 UT on Sept. 20. Also Cat 72 and 80 were flickering with plenty of C-flares on Sept. 19 and 20. On Sept. 21, Cat 82 took over and produced the first M-flare of the week: an M1.8 flare peaking at 12:23. Together with Cat 72, this region kept the level of activity very high duringhthe following days. The main event on Sept. 22 was the X1.4 flare in Cat 82, peaking at 11:00 UT. This flare was associated with a type II shock in the Humain data around 10:40 UT, a global EUV-wave (e.g. in PROBA2/SWAP difference movies) and a strong CME. Three more M-flares occurred on Sept 23, originating from Cat 72 and Cat 82. The most active day of the week was without a doubt Sept. 24, when 8 M-flares occurred as well as an X1.9 flare with peak time 09:40 UT, which was associated with Type II and II radio bursts is Humai!
n and a EUV wave in PROBA2/SWAP. Once more, Cat 82 was responsible for this event. The M flares originated in Cat 72, Cat 82 and Cat 83. THe most prominent one was a long duration M7.1 flare in Cat 82 with peak time 13:17 UT, accompanied by a strong CME. Six more M-flares were observed on Sept. 25 in Cat 82 an 83, the largest one an M7.4 flare peaking at 04:50 UT in Cat 82, associated with an EUV wave.
The first CME of the week was observed on Sept 19, originated from CAT 80 (NOAA AR 1301) on the east limb, came into the SOHO/LASCO field of view at 12:42 UT and was not earth-directed. In the following days a multitude of CME's was observed with SOHO/LASCO. Comparison to the STEREO/COR2 data revealed that these were linked to events occurring of the far side of the Sun. On Sept 22, the X1.4 flare was associated with a large scale CME. STEREO-A and B spacecrafts imaged this event as halo CME. Due to the location of the source region on the east limb, this CME was not directed straight at Earth, but we were in line to receive a glancing blow from it on Sept. 25. Several CME's were observed on Sept. 24 and 25 related to the M- and X-class flaring on those days. The most important one was associated with the long duration M7.1 flare on Sept 24, coming into the STEREO/COR2 field of view at 13:10 UT. Its speed was estimated to be around 1100 km/s. As none of the source regions of!
these CME's were at the center of the solar disk at the time of flaring, we expected possible glancing blows from these events.
GEOMAGNETIC ACTIVITY
--------
The proton flux measured by the GOES satellite has been rising since the long duration X flare event on Sept. 22, and increased further due to the numerous flares after this event. The >10MeV threshold was crossed just before midnight on Sept 23 and will remain elevated for the coming days. A shock was observed in the solar wind parameters measured by ACE around 11 UT this morning, probably related to the CME associated with the X flare on September 22. The total magnetic filed strength jumped to 10 nT, while the solar wind speed increased to 380 km/s. Geomagnetic conditions were quiet throughout the week: the Dourbes K-index never exceed the level of 3.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Sep 19 /// 093 141 003 B8.0 0 0
2011 Sep 20 121 083 144 006 B7.1 0 0
2011 Sep 21 110 076 144 004 C1.0 1 0
2011 Sep 22 111 072 151 006 C1.4 1 1
2011 Sep 23 107 056 158 003 C1.3 3 0
2011 Sep 24 /// 074 190 004 C1.6 8 1
2011 Sep 25 /// 080 169 005 C2.7 6 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
21 1204 1223 1245 M1.8 VI/1 82 1302
22 0953 1000 1009 M1.1 72 1302
22 1029 1101 1144 X1.4 970 II/2 82 1302
23 0147 0159 0210 N25W63 M1.6 1N 72 1295
23 2154 2215 2234 N23W73 M1.6 SF 210 VI/1,III/1,CTM/1 82 1295
23 2348 2356 0004 N11E52 M1.9 SF 220 III/3,II/3 82 1302
24 0921 0940 0948 N12E60 X1.9 2B 660 II/2,IV/3,V/2,III/2 82 1302
24 1233 1320 1410 M7.1 12000 82 1302
24 1636 1659 1715 M1.7 IV/1 1295
24 1719 1725 1731 M3.1 82 1302
24 1759 1815 1824 N15E56 M2.8 1B 82 1302
24 1909 1921 1941 M3.0 270 III/2,II/2 82 1302
24 2029 2036 2042 M5.8 82 1302
24 2123 2127 2132 S29W67 M1.2 SF 1303
24 2345 2358 0009 S29W68 M1.0 SF VI/2,IV/2 1303
25 0227 0233 0237 N12E49 M4.4 SF 82 1302
25 0431 0450 0505 N11E47 M7.4 2N 150 IV/2 1302
25 0846 0849 0852 N15E45 M3.1 1N 1302
25 0925 0935 0953 M1.5 250 1303
25 1526 1533 1538 N16E43 M3.7 2B 180 III/2 1302
25 1651 1658 1709 S28W75 M2.2 SF 1302
#--------------------------------------------------------------------#
# 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 560 from 2011 Sep 19
SOLAR ACTIVITY
--------
The past week featured strong solar activity with continuous flaring at C-class level, 19 M-flares and 2 X-flares. During the course of the the week, the GOES X-ray background level increased from B to high C-level. The most prominent active regions on the solar disk were Catania 72 and 74 (NOAA AR 1295 and 1296), Catania 80 (NOAA AR 1301, Catania 82 (NOAA AR 1302) and Catania 83 (NOAA AR 1303).
The main events produced by Cat 74 were a C6.2 flare peaking at 07:37 on Monday Sept. 19, associated with type III radio bursts in Humain, and a C9.5 flare with peak time 05:13 UT on Sept. 20. Also Cat 72 and 80 were flickering with plenty of C-flares on Sept. 19 and 20. On Sept. 21, Cat 82 took over and produced the first M-flare of the week: an M1.8 flare peaking at 12:23. Together with Cat 72, this region kept the level of activity very high duringhthe following days. The main event on Sept. 22 was the X1.4 flare in Cat 82, peaking at 11:00 UT. This flare was associated with a type II shock in the Humain data around 10:40 UT, a global EUV-wave (e.g. in PROBA2/SWAP difference movies) and a strong CME. Three more M-flares occurred on Sept 23, originating from Cat 72 and Cat 82. The most active day of the week was without a doubt Sept. 24, when 8 M-flares occurred as well as an X1.9 flare with peak time 09:40 UT, which was associated with Type II and II radio bursts is Humai!
n and a EUV wave in PROBA2/SWAP. Once more, Cat 82 was responsible for this event. The M flares originated in Cat 72, Cat 82 and Cat 83. THe most prominent one was a long duration M7.1 flare in Cat 82 with peak time 13:17 UT, accompanied by a strong CME. Six more M-flares were observed on Sept. 25 in Cat 82 an 83, the largest one an M7.4 flare peaking at 04:50 UT in Cat 82, associated with an EUV wave.
The first CME of the week was observed on Sept 19, originated from CAT 80 (NOAA AR 1301) on the east limb, came into the SOHO/LASCO field of view at 12:42 UT and was not earth-directed. In the following days a multitude of CME's was observed with SOHO/LASCO. Comparison to the STEREO/COR2 data revealed that these were linked to events occurring of the far side of the Sun. On Sept 22, the X1.4 flare was associated with a large scale CME. STEREO-A and B spacecrafts imaged this event as halo CME. Due to the location of the source region on the east limb, this CME was not directed straight at Earth, but we were in line to receive a glancing blow from it on Sept. 25. Several CME's were observed on Sept. 24 and 25 related to the M- and X-class flaring on those days. The most important one was associated with the long duration M7.1 flare on Sept 24, coming into the STEREO/COR2 field of view at 13:10 UT. Its speed was estimated to be around 1100 km/s. As none of the source regions of!
these CME's were at the center of the solar disk at the time of flaring, we expected possible glancing blows from these events.
GEOMAGNETIC ACTIVITY
--------
The proton flux measured by the GOES satellite has been rising since the long duration X flare event on Sept. 22, and increased further due to the numerous flares after this event. The >10MeV threshold was crossed just before midnight on Sept 23 and will remain elevated for the coming days. A shock was observed in the solar wind parameters measured by ACE around 11 UT this morning, probably related to the CME associated with the X flare on September 22. The total magnetic filed strength jumped to 10 nT, while the solar wind speed increased to 380 km/s. Geomagnetic conditions were quiet throughout the week: the Dourbes K-index never exceed the level of 3.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2011 Sep 19 /// 093 141 003 B8.0 0 0
2011 Sep 20 121 083 144 006 B7.1 0 0
2011 Sep 21 110 076 144 004 C1.0 1 0
2011 Sep 22 111 072 151 006 C1.4 1 1
2011 Sep 23 107 056 158 003 C1.3 3 0
2011 Sep 24 /// 074 190 004 C1.6 8 1
2011 Sep 25 /// 080 169 005 C2.7 6 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
21 1204 1223 1245 M1.8 VI/1 82 1302
22 0953 1000 1009 M1.1 72 1302
22 1029 1101 1144 X1.4 970 II/2 82 1302
23 0147 0159 0210 N25W63 M1.6 1N 72 1295
23 2154 2215 2234 N23W73 M1.6 SF 210 VI/1,III/1,CTM/1 82 1295
23 2348 2356 0004 N11E52 M1.9 SF 220 III/3,II/3 82 1302
24 0921 0940 0948 N12E60 X1.9 2B 660 II/2,IV/3,V/2,III/2 82 1302
24 1233 1320 1410 M7.1 12000 82 1302
24 1636 1659 1715 M1.7 IV/1 1295
24 1719 1725 1731 M3.1 82 1302
24 1759 1815 1824 N15E56 M2.8 1B 82 1302
24 1909 1921 1941 M3.0 270 III/2,II/2 82 1302
24 2029 2036 2042 M5.8 82 1302
24 2123 2127 2132 S29W67 M1.2 SF 1303
24 2345 2358 0009 S29W68 M1.0 SF VI/2,IV/2 1303
25 0227 0233 0237 N12E49 M4.4 SF 82 1302
25 0431 0450 0505 N11E47 M7.4 2N 150 IV/2 1302
25 0846 0849 0852 N15E45 M3.1 1N 1302
25 0925 0935 0953 M1.5 250 1303
25 1526 1533 1538 N16E43 M3.7 2B 180 III/2 1302
25 1651 1658 1709 S28W75 M2.2 SF 1302
#--------------------------------------------------------------------#
# 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 #
# #
#--------------------------------------------------------------------#