Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 15 - 21.04.2013 , Forecast on 22 - 29.04.2013, Carrington Rotations 2135, 2136 (21,5.03; 17,78.04.2013) SUNSPOT-FORMING ACTIVITY OF THE SUN REMAINED ON THE AVERAGE LEVEL. WEEKLY, THE AVERAGE OF SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM FOR THE PERIOD WAS MADE W = 056+5/-20. ON THE VISIBLE SOLAR DISK CONSTANTLY WERE PRESENT FROM 7 TO 3 QUIET GROUPS OF THE SUNSPOTS. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY IS EXPECTED TO BE THE AVERAGE. THE CALCULATED MOST LIKELY WEEKLY AVERAGE VALUE OF SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM FOR THE NEXT WEEK IS EXPECTED W = 050+20/-10. FLARE ACTIVITY WAS AT THE LOW LEVEL. 9 EJECTION OF SOLAR FILAMENTS ARE OBSERVED IN THIS PERIOD. BY BY SOHO AND STEREO CORONOGRAPHS DATA THERE WERE OBSERVED SOHO 54 CME FROM WHICH ONE WAS THE TYPE OF "PARTIAL GALO III", AND SIX WERE THE TYPE OF "PARTIAL GALO II". -------------------------------------------------------------------- FLARES to tm te c/p local. Class E(1-8A) AR RII/IV CME X / opt. J/m-2 DSF to te c/p local. l in deg. Fl AR CME 15.04 >0928 <2334 S23E04L039 14 CME 18.04 >1651 <0541 S10å50L297 7 18.04 1731 1801 S22W26L013 7 19.04 0009 0133 S22W23L003 9 19.04 >0111 <1258 S12W33L007 5 20.04 >0921 <2334 S32E63L253 6 20.04 >0002 <0241 N18E23L297 6 20.04 ~0512 ~0643 N25E22L298 6 21.04 0629 0825 S24E19L288 6 c/p local. - central part localization -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED ON LOW AND, WITH SMALLER PRO- BABILITY, AVERAGE LEVEL. HOWEVER THERE ARE A PROBABILITY OF EMERGENCE OF THE NEW FAST MAGNETIC FLUXES IN AR11726 (N13L323, Sp = 260 m.v.h.) WHICH APPEARED ON THE VISIBLE SOLAR DISK (E07) 18.03, AND CONSTANTLY DEVELOPED AT EVOLUTIONARY SPEED WITH NUMEROUS SMALL FLARES. DESPITE THE DIFFICULT MAGNETIC CONFIGURATION, SIGNIFICANT FLARES IN IT ARE POSSIBLE ONLY WITH A EMERGING FAST MAGNETIC FLUX. LET'S WAIT. ON THE VISIBLE SOLAR DISK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end Å end S end W end EE R Observatories CH - S18L299 S45L257 S55L297 S30L317 25.04 3 SDO, SOHO.. CH - N45L013 N40L353 N22L015 N35L025 20.04 1 SDO, SOHO.. CH - N40L289 N18L257 S08L295 N02L307 25.04 3 SDO, SOHO.. R - solar rotations; KP - KITT PEAK solar observatory; EE-date of possible geomag. disturbation in the Earth's environment. ---------------------------------------------------------------------- WITH 16.04/04 UT EARTH WAS IN "+" SECTOR OF THE INTERPLANETARY MAGNE- TIC FIELD. THE FOLLOWING SECTOR BOUNDARY +/- EARTH SHOULD TO PASS 22 24 APRIL. APRIL 15 16 17 18 19 20 21 APRIL Wus 099 097 089 086 101 101 076 F10.7 113 113 108 105 099 105 109 èbcg ÷3.1 ÷3.1 ÷2.8 B2.8 ÷2.5 ÷2.7 B5.1 wt/m-2 GOES Sp 590 460 500 450 300 340 360 m.v.h. N 3 IMF - -/+ + + + + + áóå Å>2 1.6å+6 2.8E+6 3.2E+6 6.2å+6 8.1å+6 3.2å+6 1.8E+6 GOES Ie>2 GOES Nm% THULE Ap 4 2 2 3 2 3 3 nô áÒ Dst nô KIOTO Amsc 8 10 7 5 6 8 6 nô IZMIRAN -------------------------------------------------------------------- Å>2 - a fluence in (electrons/cm2-day-sr) with E>2 MeV. Ie>2 - the maximum intensity of a flux of electrons in geostationary orbits in days according to GOES 15 in (electrons/cm2-s-sr) for events > 1000 p.f.u. MINOR SOLAR PROTON EVENT WAS OCCURENCE FROM BACK SIDE SOURCE: Pr>10 MeV, to-21/0930 UT; max-3 pfu, tm-21/1640 UT; te- in progres. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSTATIONARY ORBIT VERY HIGH LEVEL WAS NOT OBSERVED. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSTATIONARY ORBIT VERY HIGH LEVEL IS NOT EXPECTED. GEOMAGNETIC CONDITIONS REMAINED UNSETTLED AND QUITE. NEXT WEEK THE GEOMAGNETIC CONDITION IS EXPECTED UNSETTLED AND QUIET. HIGHLIGHT AND FORECAST COMPOSED FROM DATA OF NOAA SWPC http://www.sec.noaa.gov, OF THE SOLAR INFLUENCES DATA ANALYSIS CENTER - SIDC, BELGIUM http://sidc.oma.be/index.php3, OF THE IZMIRAN, RUSSIA http://www.izmiran.ru