Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 10 - 16.04.2017, Forecast on 17 - 24.04.2017, Carrington Rotation 2189 (2,37.04.2017) Earth above the ecliptic (-5.9, -5,5) deg. (S30-N28 is geoeffectiveness zone) SUNSPOT-FORMING ACTIVITY WAS ON A VERY LOW LEVEL. THE ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE IN- TERNATIONAL SYSTEM (old) FOR THE THE PERIOD IS W=4+4/-4 (Wn= 7+5/-7). ON THE VISIBLE DISC OF THE SUN ONE SMALL QUITE SUNSPOT GROUP. NEXT WEEK SUNSPOT-FORMING ACTIVITY IS EXPECTED AT THE LOW AND MIDDLE LEVELS. THE ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELA- TIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=30+20/-20. FLARE ACTIVITY WAS AT THE VERY LOW LEVEL. TWO SOLAR FILAMENT EJECTION OCCURRENCES THROUGH THE PERIOD. ACCORDING TO THE SOHO AND STEREO CORO- NOGRAPHS DATA > 13 CMEs HAVE BEEN OBSERVED. ---------------------------------------------------------------------- FLARES to tm te local. Class E(1-8A) AR RII/IV CME X-ray/Ïp J/m-2 DSF to te ËÏÏÒÄÉÎÁÔÙ l × ÇÒÁÄ. Fl Aï CME/to 11.04 0704 1441 S19W62L308 26 13.04 >0943 >2308 N31E44L277 15 ---------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY IS EXPECTED AT A LOW AND VERY LOW LEVELS. ON THE VISIBLE SOLAR DISK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end E end S end W end Sch EE R G Space Obser. CH + N38L298 N25L293 N08L303 N30L308 10.04 >9 SDO, SOHO.. CH + N12L185 S20L175 S23L173 S18L190 12200 19.04 7 G1 SDO, SOHO.. CH + S15L225 S22L223 S30L221 S20L225 17.04 7 G1 SDO, SOHO.. Both last CH, perhaps, parts of one CH. Sch - CH Square in Mm**2 (in square megameters) near the central meri- dian on http://sdowww.lmsal.com/suntoday/; n/d - no data; R - solar rotations; EE-date of possible geomag. disturbance in the Earth's environment. G(0-5)-geoeffectivity in last solar rotation on the middle latitudes. A-active geomagnetic condition. ------------------------------------------------------------------------ FROM 16.04/05 UT THE EARTH IS IN "+" SECTOR OF THE INTERPLANETARY MAG- NETIC FIELD. 13 - 15.04 THE SIGN OF SECTOR HAVE BEEN CHANGED. THE FOL- LOWING SECTOR BOUNDARY +/- THE EARTH HAS EXPECTED TO PASS 24.04. APRIL 10 11 12 13 14 15 16 APRIL Wus 013 012 013 012 011 011 000 F10.7 074 075 071 074 073 073 075 èbcg á5.8 á4.5 á4.7 á4.8 á4.6 á4.5 á7.7 GOES Sp 040 040 020 020 010 010 000 msh N IMF - - - ~ ~ ~ -/+ DSCOVR Å>2 1.3å+8 4.1å+7 7.9E+7 1.2E+8 5.89+7 3.2å+7 3.6å+7 GOES Ie>2 3855 2748 1799 2552 2534 1427 909 pfu Ap 6 12 6 4 14 6 4 nô BOULDER Dst nô KIOTO Amsc 4 11 3 5 10 6 4 nô IZMIRAN ------------------------------------------------------------------ Å>2 - Daily Electron Fluency e/(cm2-ster-day) with E>2 MeV. Ie>2 - the maximum intensity of electron flux in geostationary or- bits in days according to GOES15 in (electrons/cm2.s.sr) for events > 1000 pfu. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS BE- GINING AT 09.04/1330 UT AND OBSERVED 9-15.04. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSTATIONARY ORBIT OF VERY HIGH LEVEL IS EXPECTED 18 - 24.04. THE GEOMAGNETIC CONDITION WAS UNSETTLED AND QUITE. NEXT WEEK GEOMAGNETIC CONDITION WILL BE QUIET AND UNSETTLED. HIGHLIGHT AND FORECAST COMPOSED FROM DATA: NOAA SWPC, BOULDER, USA http://www.swpc.noaa.gov, THE SOLAR INFLUENCES DATA ANALYSIS CENTRE, SIDC, BRUSSELS, BELGIUM http://sidc.oma.be/index.php3, THE IZMIRAN, MOSCOW, TROITSK, RUSSIA http://www.izmiran.ru V. Ishkov