:Issued: 2012 Jan 24 1524 UTC
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity #
#--------------------------------------------------------------------#
WEEK 577 from 2012 Jan 16
SOLAR ACTIVITY
--------------
Solar activity was dominated by Catania sunspot groups 20 and 21 (NOAA ARs 1401 and 1402 respectively), which produced numerous C-class flares and three M-class flares (two in Catania sunspot group 20 and one in Catania sunspot group 21). The first two M-class flares (on January 17 and 18) were confined, and the M3.2 flare on January 19 was associated with a full halo CME (see below).
Three halo CMEs were detected by SOHO/LASCO during the week. A full halo CME was detected on January 16, first appearing in the LASCO C2 field of view at 03:12 UT and moving at a speed around 500 km/s (according to the CACTus software). The CME was associated with the C6.5 flare peaking at 04:44 UT in Catania sunspot group 21 (NOAA AR 1402) situated at N34E86, coronal dimmings and a post-eruption loop arcade detected by SDO/AIA. Due to the position of the CME source region near the solar limb, the bulk of the CME was not directed at the Earth. Only the CME-driven shock arrived at the Earth on January 21 (see below).
A partial halo CME was detected on January 18, first appearing in the LASCO C2 field of view at 12:12 UT. The CME had angular width around 140 degrees and moved at the speed around 720 km/s. The CME was associated with the coronal dimmings and filament eruption near the solar disk center, and a post-eruption arcade in Catania sunspot group 16 (NOAA AR 1399), as observed by SDO/AIA starting around 10:13 UT. A B9.6 flare peaking at 12:30 UT associated with this eruption was detected by GOES. The bulk of the CME material was moving southward of ecliptic. This CME probably interacted with the full halo CME erupted on January 19, and the joint interplanetary disturbance arrived at the Earth on January 22 (see below).
A full halo CME was detected on January 19, first appearing in the LASCO C2 field of view at 15:24 UT and moving at the plane-of-the-sky speed around 1300 km/s. The CME was associated with coronal dimmings, filament eruption and a post-eruption arcade in and around Catania sunspot group 21 (NOAA AR 1402), as observed by SDO/AIA starting around 13:58 UT. An M3.2 flare peaking at 16:05 UT associated with this eruption was detected by GOES. The bulk of the CME material was moving northward of the ecliptic plane. This CME probably interacted with the partial halo CME erupted on January 18, and the joint interplanetary disturbance arrived at the Earth on January 22 (see below).
The flux of solar protons at energies above 10 MeV started to rise on January 19, probably in association with the propagating interplanetary shock wave driven by the full halo CME erupted on January 19. The proton flux remained significantly above the background level, although below the event threshold, until the end of the week.
GEOMAGNETIC ACTIVITY
--------------------
On January 16 the Earth passed through the interaction region between a slow and a faster sold wind flow. The faster solar wind flow originated from a narrow low-latitude coronal hole. Although the interplanetary magnetic field (IMF) magnitude reached 15 nT, the geomagnetic conditions were quiet due to relatively low solar wind speed (up to 520 km/s) and fluctuating north-south IMF component. On January 17-20 the Earth was inside a slow solar wind flow, and geomagnetic conditions remained quiet.
An interplanetary shock wave was detected by ACE at 04:00 UT on January 21. The shock was most probably associated with the full halo CME observed on the Sun on January 16 (see above). No ICME material was detected. Due to low downstream solar wind speed, no geomagnetic disturbance resulted from the shocked solar wind flow.
Another interplanetary shock wave was detected by ACE at 05:15 UT on January 22. The proton flux peaked at the shock arrival, but did not reach the event threshold. The shock was driven by the complex ICME resulting from halo CMEs observed on the Sun on January 18 and 19 (see above), which interacted on their way to the Earth. The peak solar wind speed was moderate (around 480 km/s), but the IMF magnitude reached 33 nT in the sheath region between the shock and the ICME. The north-south IMF component Bz was fluctuating in the post-shock sheath, resulting only in active geomagnetic conditions (K = 4). The ICME had only a glancing blow at the Earth, with ICME material arriving late on January 22 and on January 23. The IMF magnitude already decreased at that time, resulting only in minor geomagnetic storm conditions (K = 5) as reported by NOAA and IZMIRAN.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2012 Jan 16 /// 098 140 010 C1.0 0 0
2012 Jan 17 /// 092 139 008 B5.2 1 0
2012 Jan 18 143 085 148 005 B5.7 1 0
2012 Jan 19 133 069 157 002 B5.9 1 0
2012 Jan 20 162 063 141 005 B6.0 0 0
2012 Jan 21 /// 068 142 008 B4.9 0 0
2012 Jan 22 /// 062 141 025 B5.5 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
17 0441 0453 0507 N18E54 M1.0 1N 1401
18 1904 1912 1927 N17E33 M1.7 1N 20 1401
19 1344 1605 1750 N32E22 M3.2 SF 21 1402
#--------------------------------------------------------------------#
# 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 577 from 2012 Jan 16
SOLAR ACTIVITY
--------------
Solar activity was dominated by Catania sunspot groups 20 and 21 (NOAA ARs 1401 and 1402 respectively), which produced numerous C-class flares and three M-class flares (two in Catania sunspot group 20 and one in Catania sunspot group 21). The first two M-class flares (on January 17 and 18) were confined, and the M3.2 flare on January 19 was associated with a full halo CME (see below).
Three halo CMEs were detected by SOHO/LASCO during the week. A full halo CME was detected on January 16, first appearing in the LASCO C2 field of view at 03:12 UT and moving at a speed around 500 km/s (according to the CACTus software). The CME was associated with the C6.5 flare peaking at 04:44 UT in Catania sunspot group 21 (NOAA AR 1402) situated at N34E86, coronal dimmings and a post-eruption loop arcade detected by SDO/AIA. Due to the position of the CME source region near the solar limb, the bulk of the CME was not directed at the Earth. Only the CME-driven shock arrived at the Earth on January 21 (see below).
A partial halo CME was detected on January 18, first appearing in the LASCO C2 field of view at 12:12 UT. The CME had angular width around 140 degrees and moved at the speed around 720 km/s. The CME was associated with the coronal dimmings and filament eruption near the solar disk center, and a post-eruption arcade in Catania sunspot group 16 (NOAA AR 1399), as observed by SDO/AIA starting around 10:13 UT. A B9.6 flare peaking at 12:30 UT associated with this eruption was detected by GOES. The bulk of the CME material was moving southward of ecliptic. This CME probably interacted with the full halo CME erupted on January 19, and the joint interplanetary disturbance arrived at the Earth on January 22 (see below).
A full halo CME was detected on January 19, first appearing in the LASCO C2 field of view at 15:24 UT and moving at the plane-of-the-sky speed around 1300 km/s. The CME was associated with coronal dimmings, filament eruption and a post-eruption arcade in and around Catania sunspot group 21 (NOAA AR 1402), as observed by SDO/AIA starting around 13:58 UT. An M3.2 flare peaking at 16:05 UT associated with this eruption was detected by GOES. The bulk of the CME material was moving northward of the ecliptic plane. This CME probably interacted with the partial halo CME erupted on January 18, and the joint interplanetary disturbance arrived at the Earth on January 22 (see below).
The flux of solar protons at energies above 10 MeV started to rise on January 19, probably in association with the propagating interplanetary shock wave driven by the full halo CME erupted on January 19. The proton flux remained significantly above the background level, although below the event threshold, until the end of the week.
GEOMAGNETIC ACTIVITY
--------------------
On January 16 the Earth passed through the interaction region between a slow and a faster sold wind flow. The faster solar wind flow originated from a narrow low-latitude coronal hole. Although the interplanetary magnetic field (IMF) magnitude reached 15 nT, the geomagnetic conditions were quiet due to relatively low solar wind speed (up to 520 km/s) and fluctuating north-south IMF component. On January 17-20 the Earth was inside a slow solar wind flow, and geomagnetic conditions remained quiet.
An interplanetary shock wave was detected by ACE at 04:00 UT on January 21. The shock was most probably associated with the full halo CME observed on the Sun on January 16 (see above). No ICME material was detected. Due to low downstream solar wind speed, no geomagnetic disturbance resulted from the shocked solar wind flow.
Another interplanetary shock wave was detected by ACE at 05:15 UT on January 22. The proton flux peaked at the shock arrival, but did not reach the event threshold. The shock was driven by the complex ICME resulting from halo CMEs observed on the Sun on January 18 and 19 (see above), which interacted on their way to the Earth. The peak solar wind speed was moderate (around 480 km/s), but the IMF magnitude reached 33 nT in the sheath region between the shock and the ICME. The north-south IMF component Bz was fluctuating in the post-shock sheath, resulting only in active geomagnetic conditions (K = 4). The ICME had only a glancing blow at the Earth, with ICME material arriving late on January 22 and on January 23. The IMF magnitude already decreased at that time, resulting only in minor geomagnetic storm conditions (K = 5) as reported by NOAA and IZMIRAN.
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DAILY INDICES
DATE RC EISN 10CM Ak BKG M X
2012 Jan 16 /// 098 140 010 C1.0 0 0
2012 Jan 17 /// 092 139 008 B5.2 1 0
2012 Jan 18 143 085 148 005 B5.7 1 0
2012 Jan 19 133 069 157 002 B5.9 1 0
2012 Jan 20 162 063 141 005 B6.0 0 0
2012 Jan 21 /// 068 142 008 B4.9 0 0
2012 Jan 22 /// 062 141 025 B5.5 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
17 0441 0453 0507 N18E54 M1.0 1N 1401
18 1904 1912 1927 N17E33 M1.7 1N 20 1401
19 1344 1605 1750 N32E22 M3.2 SF 21 1402
#--------------------------------------------------------------------#
# 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 #
#--------------------------------------------------------------------#
