martedì 17 gennaio 2012

SIDC Weekly Bulletin

:Issued: 2012 Jan 16 2031 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 576 from 2012 Jan 09 

SOLAR CONDITIONS
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Solar activity was rather quiet with only a few small C flares during the first half of the week. Two noteworthy flares occurred: a long duration C2.5 flare in the morning of Jan 12 and a M1.4 flare on Jan 14. Both flares originated on the eastern limb in an active region that rotated onto the disk around 15 Jan. The NOAA AR numbers related to this activity are 11401 and 11402. Worth to mention also is the appearance of several sunspot groups on the solar disk, one on Jan 12 in the north-east (corresp. to NOAA 11396),  one in the south-east late on Jan 12 (corresp. to NOAA 11397), one on Jan 13 in the north around central meridian (corresp. to NOAA 11398) and a small group in the south-west early on Jan 14 (corresp. to NOAA 11400). None of these active regions produced significant activity up till now.

Several CMEs erupted during this week, although none were geoeffective. On Jan 10-11 a slow streamer blowout occurred in the east, related low-coronal activity was seen in SDO and SWAP images as expanding loops. A CME was associated with the long duration C2.5 flare on Jan 12, and was directed to the north-east. Additionally on Jan 12, there was a large filament eruption near central meridian situated in the northern hemisphere leading into a CME seen north of the occulter in LASCO.  On Jan 13 there were three CMEs, two of them were first observed in LASCO C2 around 9UT at the north-east and north-west and one was first observed around 13UT directed to the south-east. It is hard to link any on-disk signature to these CMEs. On Jan 15 there was a CME observed in LASCO C2 around 05:48 UT in the north-east, presumably originating from the back side.

GEOMAGNETIC CONDITIONS
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Geomagnetic conditions were quiet during this week. The increase of the IMF magnitude, as well as the sector boundary crossing in the night of January 14/15 indicated a possible arrival of a faster solar wind flow from a narrow low-latitude elongated coronal hole, that was at central meridian on Jan 12.

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DAILY INDICES
DATE          RC  EISN  10CM  Ak  BKG    M  X
2012 Jan 09  102    050  142  010  B4.8  0  0
2012 Jan 10  072    042  129  005  B4.0  0  0
2012 Jan 11  089    041  120  007  B5.4  0  0
2012 Jan 12  060    034  117  008  B5.1  0  0
2012 Jan 13  092    047  124  008  B4.9  0  0
2012 Jan 14  119    076  132  003  B5.9  1  0
2012 Jan 15  ///    097  134  004  B6.2  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  1314  1318 1320 N14E88 M1.4                                        1401 SolarSoft Events location


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# Solar Influences Data analysis Center - RWC Belgium                #
# Royal Observatory of Belgium                                      #
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