:Issued: 2012 Mar 09 1341 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 20309 SIDC SOLAR BULLETIN 09 Mar 2012, 1316UT SIDC FORECAST (valid from 1230UT, 09 Mar 2012 until 11 Mar 2012) SOLAR FLARES : Active (M-class flares expected, probability >= 50%) GEOMAGNETISM : Major geomagnetic storm expected (A>=50 or K>=6) SOLAR PROTONS : Proton event in progress (>10 MeV) PREDICTIONS FOR 09 Mar 2012 10CM FLUX: 142 / AP: 060 PREDICTIONS FOR 10 Mar 2012 10CM FLUX: 144 / AP: 023 PREDICTIONS FOR 11 Mar 2012 10CM FLUX: 142 / AP: 044 COMMENT: Catania sunspot group 65 (NOAA AR 1429) started to decay, although it still maintains the beta-gamma-delta configuration of its photospheric magnetic field. We expect M-class flares from this active region, although an X-class flare is still not excluded. An unnumbered sunspot group appeared from behind the north-east limb and produced a CME (not a halo) this morning. C- and even M-class flares are possible in this active region. SOHO/LASCO detected a full halo CME in association with the M6.3 flare in Catania sunspot group 65 (NOAA AR 1429) this morning. The CME first appeared in the LASCO C2 field of view at 04:14 UT and had a speed around 750 km/s. We expect the CME arrival at the Earth late on March 11 - early on March 12. An evaluation of the possible erupting flux rope orientation on the basis of HMI photospheric magnetograms and AIA images of the post-eruption arcade gives the south-east-north (SEN, left-handed) configuration. Due to the position of the CME source region close to the solar central meridian, we expect a nearly central encounter of the resulting ICME, which will probably be a magnetic cloud with leading southward field. A strong geomagnetic storm (K = 7 or higher) is probable. The Earth is now inside the post-shock solar wind flow generated by the ICME corresponding to the halo CME erupted on March 7. The interplanetary magnetic field (IMF) is currently southward, resulting in a severe magnetic storm (K = 7 reported by NOAA). Although the IMF magnitude is not very high (around 10 nT), it was strongly fluctuating in the past 24 hours, so a further development of the storm is not excluded. The solar wind speed measured by SOHO/CELIAS is currently high (around 900 km/s) and CELIAS data exhibit two important discontinuities in the solar wind speed today (at 03:44 UT and 08:18 UT). Neither of these discontinuities seems to correspond to a sudden increase of the IMF magnitude measured by ACE, so they do not appear to be shock waves. The SEP event is still on-going, with proton fluxes a TODAY'S ESTIMATED ISN : 070, BASED ON 15 STATIONS. SOLAR INDICES FOR 8 Mar 2012 WOLF NUMBER CATANIA : 112 10CM SOLAR FLUX : 140 AK CHAMBON LA FORET : /// AK WINGST : /// ESTIMATED AP : 027 ESTIMATED ISN : 066, BASED ON 26 STATIONS. NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM RADIO BURST TYPES Catania NOAA NOTE 09 0322 0353 0418 N15W03 M6.3 III/1,V/2,II/2 65 1429 Location taken from SolarSoft Events END BT #--------------------------------------------------------------------# # 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://sidc.be/products/meu # # 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 # #--------------------------------------------------------------------#