Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 02 - 08.04.2012, Forecast on 09 - 16.04.2012, Carrington Rotations 2122 (04,28.04.2012) SOLAR SUNSPOT ACTIVITY OF LAST PERIOD WAS ON AVERAGE, AND BY THE PE- RIOD END ON LOW LEVELS. ESTIMATED, RATING, WEEKLY AVERAGE OF SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM FOR THE PERIOD WAS MADE W=029+11/ -14. ON THE VISIBLE SOLAR DISK CONSTANTLY PRESENT FROM 5 TO 2 QUTE, SMALL SUNSPOT GROUPS. NEXT WEEK THE SUNSPOT ACTIVITY IS EXPECTED TO BE LOW. THE CALCULA- TED MOST LIKELY WEEKLY AVERAGE VALUE OF SUNSPOT NUMBER IN THE INTER- NATIONAL SYSTEM FOR THE NEXT WEEK W=040+20/-10. FLARE ACTIVITY AT 4, 5 AND 7.04 WAS ON THE LOW LEVELS AND OTHER DAYS AT VERY LOW. BY DATA OF SOHO CORONOGRAPHS FOR THE PERIOD IT WAS OBSER- VED 21 CORONAL MASS EJECTIONS AMONG WHICH 4 WERE TYPE "PARTIAL HALO II" (2, 5 é 7.04) ------------------------------------------------------------------- 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 02.04 <0224 N26E14L320 ? 11450 CME/0224 UT 02.04 <2348 N30E11L323 ? 11450 CME/2348 UT 05.04 2049 2110 N18W29L321 12 C1.5/SF 11450 II/1 CME/2125 UT 07.04 1825 1900 N17W36L304 7 C2.4/ 11451 CME/2125 UT c/p local. - central part localization -------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY IS EXPECTED ON LOW AND VERY LOW LEVELS. ON THE VISIBLE SOLAR DISK DURING THE LAST WEEK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end Å end S end W end EE R Observatories CH + S23L329 S25L325 S30L327 S25L335 05.04 1 KP, SDO, SOHO... CH - N22L229 N10L223 S08L234 N08L242 12.04 3 KP, SDO, SOHO... CH - S17L236 S30L231 S38L234 S30L248 12.04 4 KP, SDO, SOHO... R - solar rotations; KP - KITT PEAK solar observatory; EE-date of possible geomag. disturbation in the Earth's environment. --------------------------------------------------------------------- AFTER 5.04/1130 UT THE EARTH WAS IN "+" SECTOR OF THE INTERPLANETARY MAGNETIC FIELD. THE FOLLOWING SECTOR BOUNDERY + /- THE EARTH SHOULD PASS 10.04. APRIL 02 03 04 05 06 07 08 APRIL Wus 067 062 060 050 039 038 025 F10.7 106 104 102 101 097 099 093 èbcg B2.4 ÷2.2 B1.5 ÷2.0 ÷1.6 ÷1.5 ÷1.2 GOES Sp 250 220 220 180 210 110 130 Nnew 2 IMF - - - -/+ + + + ACE Å>2 1.9å+6 1.0å+7 6.0E+6 1.4å+6 3.0å+6 4.3å+6 1.0å+7 GOES Nm% THULE Ap 8 5 6 15 3 9 5 áÒ Dst ëIOTO Amsc 12 8 10 14 8 9 9 IZMIRAN --------------------------------------------------------------- THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT VERY HIGH LEVEL OF FLUX WAS NOT OBSERVED. THE GREATER THAN 2 MeV ELECTRON FLUX AT HIGH LEVEL IS EXPECTED 13 -16.04. GEOMAGNETIC CONDITIONS BEEN UNSETTLED AND QUIET. NEXT WEEK GROWTH OF GEOMAGNETIC DISTURBANCE IS POSSIBLE ON APRIL 9 WHEN TO EARTH DISTURBANCE FROM SOLAR FILAMENT EJECTION WILL COME ON APRIL 5. PROBABILITY MAGNETIC STORM OF 8-9.04 NO MORE THAN 30%. ON APRIL 12 EARTH WILL PASS IN THE HIGHSPEED STREAM FROM RECURRENT FROM NEAR EQUATORIAL CORONAL HOLE AND, A LITTLE EARLIER, TO EARTH SLIDING DISTURBANCE FROM SOLAR FILAMENT EJECTION 7.04 WILL COME. WITH PROBABILITY ABOUT 60% 12-13.04 IT IS POSSIBLE TO WAIT FOR THE MINOR MAGNETIC STORM. IN OTHER DAYS THE GEOMAGNETIC SITUATION 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