:Issued: 2010 Jun 14 1259 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 493 from 2010 Jun 07 SOLAR ACTIVITY -------------- This week was marked by a significant increase of the solar activity. Flaring activity remained first very low, despite the appearance of several new active regions, and then it became moderate on June 12 and 13. The main active region was first Catania#81 (NOAA11078) which appeared on June 8, reached a maximum extension on June 10 (Type E, beta-gamma) and disappeared at the West limb on June 12. This region was peculiar, as it featured a reversed magnetic polarity. Then, the activity was dominated by active regions Catania#86 (NOAA11079) and Catania#87 (NOAA11081). Those active regions, which appeared in June 11, produced multiple C flares and CMEs from June 12 onwards, with also an M2.0 flare on June 12 00:30 UT from Catania#87 and a M1.0 flare on June 13 5:30 UT from Catania#86, each associated with a CME. The GOES X-ray background rose above the B1 level on June 12 and 13. On June 13, a recurrent trans-equatorial coronal hole crossed the central meridian. This structure has grown significantly since the last solar rotation: two smaller mid-latitudes coronal holes have connected across the solar equator. It may produce significant geomagnetic disturbances on June 15 and 16. GEOMAGNETIC ACTIVITY -------------------- Geomagnetic conditions were mostly quiet over the whole week, with only brief unsettled intervals on June 6, 10 and 13. These were due to weak solar wind streams that all remained below a maximum velocity of 450km/s. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2010 Jun 07 025 007 69 006 A4.3 0 0 2010 Jun 08 039 009 72 004 A5.3 0 0 2010 Jun 09 037 021 72 006 A6.5 0 0 2010 Jun 10 074 025 73 009 A5.8 0 0 2010 Jun 11 062 029 75 005 A6.8 0 0 2010 Jun 12 054 032 76 003 B1.3 1 0 2010 Jun 13 /// 017 76 008 B1.5 1 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 12 0030 0057 0102 N23W43 M2.0 SN 130 II/2 87 1081 EIT wave and limb CME 13 0530 0539 0544 S25W84 M1.0 SF II/1 86 1079 SWAP: eruption on the limb #--------------------------------------------------------------------# # 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 # # # # For more information, see http://www.sidc.be. Please do not reply # # directly to this message, but send comments and suggestions to # # 'sidctech@oma.be'. If you are unable to use that address, use # # 'rvdlinden@spd.aas.org' instead. # # To unsubscribe, visit http://sidc.be/registration/unsub.php # #--------------------------------------------------------------------#