Solar Influences Data Center (SIDC) / RWC Belgium Royal Observatory of Belgium E-mail: Pierre.Cugnon@oma.be http://sidc.oma.be SIDC WEEKLY BULLETIN -------------------- WEEK 133 from 2003 Jul 14 SOLAR ACTIVITY -------------- Solar activity was low during the period. There was not a single M-flare or X-flare reported. The biggest flare reported was a C9.8 (as measured by GOES 12) flare on July, 17 from active region 0412 (Catania sunspot group 70). Note that GOES 10 (outdated by GOES 12) recorded the same flare as being a M1.0-flare. More instrumental confusion was produced by the SOHO spacecraft. Due to a mechanical problem with the high gain antenna, the whole spacecraft was turned upside down in order to keep the antenna pointing to the Earth. The net effect is that EIT & LASCO movies show the Sun spinning in the \'wrong\' direction. Software patches to cure this anomaly are being developed. There were no halo CMEs nor proton events reported. GEOMAGNETIC ACTIVITY -------------------- Most of the week was characterized by active geomagnetic conditions. Most disturbed days were Tuesday (July 15) and especially Wednesday (July 16) with major magnetic storm levels (Kp=6) during 9 hours following an otherwise only moderate southward excursion of the interplanetary magnetic field. --------------------------------------------------------------------------- DAILY INDICES DATE RC 10CM Ak BKG M X 2003 Jul 14 132 127 016 B3.2 0 0 2003 Jul 15 152 126 031 B2.6 0 0 2003 Jul 16 150 133 031 B2.8 0 0 2003 Jul 17 149 139 018 B3.9 0 0 2003 Jul 18 153 140 019 B4.2 0 0 2003 Jul 19 153 146 032 B5.4 0 0 2003 Jul 20 218 157 021 B8.9 0 0 # RC : Sunspot index from Catania Observatory (Italy) # 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 10CM TYPE Cat NOAA NOTE