Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 15 - 21.04.2019, Forecast on 22 - 29.04.2019, Carrington Rotation 2216 (08,8.04.2019) Earth out of ecliptic (-6.6 - -6.2) deg. (S30 - N20 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY WAS AT THE LOW AND VERY LOW LE- VELS BUT 21.04 THE SUN BECAME SPOTLESS (63 DAYS ON 2019)) ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W= 8+6/-1 (Wn= 12+11/-2). ON THE SOLAR VISIBLE DISC TWO QUITE SUNSPOT GROUP - 1 SMALL AND 1 MIDDLE SIZE IN WHICH AFTER 14.02 THERE WAS ONE UNIPOLAR SUNSPOT, AND 19.02 IT LEFT BEHIND THE WESTERN LIMB WHERE IT BECAME MORE ACTIVE AND 20-22.04 ON THE LIMB IN PLACE OF IN LOCALIZATION TO REGISTRED THE II TYPE RADIO BURSTS AND CME. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WILL AT VERY LOW LEVEL AND AFTER 23.04 THE SUN WILL SPOTLESS. LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=010+1/-10. FLARE ACTIVITY WAS AT THE VERY LOW LEVELS. NO FILAMENT EJECTION AND SIX CORONAL MASS EJECTIONS (17-20.04) HAVE BEEN OBSERVED. ------------------------------------------------------------------- FLARES >M1 X-RAY CLASSES to tm te local. Class E(1-8A) AR RII/IV CME X-ray/Ïp J/m-2 DSF to te localization l × ÇÒÁÄ. Fl AR CME/to -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT LOW AND MIDDLE 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. óî - N10L235 S10L234 S40L202 S20L182 <13.4 23.04 8 - ACE SOHO... Sch - CH area in % solar hemisphere near the central meridian on https://www.solarmonitor.org/; n/d - no data; R - solar rotations; EE-date of possible geomagnetic disturbance in the Earth's environment. G(0-5)-geoeffectivity in last solar rotation on the middle latitudes. A-active geomagnetic condition. ---------------------------------------------------------------------- AFTER 20.04/12 UT EARTH IS IN "+" SECTOR OF THE INTERPLANETARY MAGNE- TIC FIELD. NEXT SECTOR BOUNDARY +/- THE EARTH MUST PASS 27.04. ---------------------------------------------------------------------- áPRIL 15 16 17 18 19 20 21 áPRIL Wus 011 011 024 023 024 011 000 F10.7 075 074 076 075 073 070 069 èbcg <á1.0 <á1.0 <á1.0 <á1.0 á8.2 á8.1 á7.2 GOES Sp 300 330 410 280 270 010 000 msh N 1 IMF - - - - - -/+ + DSCOVR Å>2 5.6E+7 1.8E+7 2.6E+7 2.3å+7 1.7å+7 7.8E+6 7.7å+6 GOES Ie>2 4149 1770 733 733 538 406 221 pfu Ap 8 6 3 2 4 3 4 nô Dst nô KIOTO Amsc 9 6 5 3 4 4 3 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 GOES-15 in (electrons/cm2.s.sr) for events > 1000 pfu. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT BEGAN 5.04/1400 UT AND 8 - 17.04 HAVE BEEN OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS NOT EXPECTED. GEOMAGNETIC CONDITION AT MEDIUM LATITUDES UP REMAINS QUIET AND UNSET- TLED. NEXT PERIOD THE MOST PROBABLE QUIET AND UNSETTLEDED GEOMAGNETIC CONDI- TION IS EXPECTED. CORONAL HOLE TOO "FRIABLE" THAT TO GIVE A SUBSTANTI- VE GEOMAGNETIC DISTURBANCE, ALTHOUGH THE AURORA WILL BE OBSERVED. 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