:Issued: 2012 May 17 0919 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 593 from 2012 May 07 SOLAR ACTIVITY -------------- Several M-flares were produced from Monday May 7 till Thursday May 10. NOAA AR 1471 was active in the beginning of the period (M1.9 flare on May 7) but most flaring and the largest flare of the period (M5.7 on May 10) was produced by NOAA AR 1476. After that, flaring activity decreased although NOAA AR 1476 retained a beta-gamma-delta configuration till the end of the period. The ACE low energy proton fluctuated since May 11 suggesting that the Earth environment was magnetically connected to NOAA AR 1476 in the second half of the period. Nevertheless, the NOAA GOES proton event threshold was not reached during the period. GEOMAGNETIC ACTIVITY --------------------- Enhanced geomagnetic conditions were observed on May 9 and May 10. KDourbes, as well as NOAA's planetary K-index registered K=4 values. This enhanced activity was a consequence of a coronal hole passing the solar central meridian. The solar wind speed, as recorded by the ACE spacecraft at L1, gradually rose from 300km/s to nearly 700 km/s with intermittent episodes in which the Bz component of the interplanetary magnetic field turned southwards. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2012 May 07 150 055 122 004 B5.9 1 0 2012 May 08 105 059 123 012 B3.5 1 0 2012 May 09 113 061 127 031 B4.1 3 0 2012 May 10 126 066 131 012 B6.5 2 0 2012 May 11 140 074 136 012 B6.1 0 0 2012 May 12 /// 066 130 012 B4.9 0 0 2012 May 13 /// 068 131 014 B4.2 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) --------------------------------------------------------------------------- NOTICEABLE EVENTS DAY BEGIN MAX END LOC XRAY OP TENCM TYPE Cat NOAA NOTE 07 1403 1431 1452 S19W46 M1.9 1N 230 IV/1 1471 08 1302 1308 1312 N13E44 M1.4 1F 69 1476 09 1221 1232 1236 N13E31 M4.7 1N 110 1476 09 1402 1408 1414 N06E22 M1.8 1B 68 III/2 1476 09 2101 2105 2109 M4.1 240 1476 10 0411 0418 0423 N13E22 M5.7 2B 690 III/2 1476 10 2020 2026 2030 N12E12 M1.7 100 25 1476 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#