Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 14 - 20.09.2020, Forecast on 21 - 27.09.2020, Carrington Rotation 2235(07,74.09.2020) Earth out of ecliptic (6.94 - 7.0) deg. (S20 - N35 is zone of geoeffectiveness) THE SUNSPOT-FORMING ACTIVITY REMAINED ON VERY LOW LEVEL. THE SUN's VISIBLE DISK WAS SPOTLESS ALL DAYS (187 SPOTLESS DAYS AT 2020). ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W= 0 (Wn= 0). NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WAS ON VERY LOW LEVEL. ON VISIBLE SOLAR DISC 22.09 ON THE NORTH HEMISPHERE MUST APPEA- RANCE SUNSPOT GROUP, WITH A GREAT PROBABILITY, OF 25 CYCLES SO- LAR ACTIVITY. LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR NEXT WEEK IS W=010+10/-10. FLARE ACTIVITY WAS AT VERY LOW LEVEL. 15 SOLAR FLARE OF LOW X-RAY CLASSES "A AND "B", ONE SOLAR FILAMENT EJECTA AND 4 CORONAL MASS EJECTIONS (16, 18, 19.09) 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 deg. Fl AR CME/to 16.09 >1007 >1200 N52E34L075 9 -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT VERY LOW LEVEL. ON THE VISIBLE SOLAR DISK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end E end S end W end Sch EE R G Spacecraft * - low geoeffectivity, the substorms with duration <6 h. only. 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. ---------------------------------------------------------------------- FROM 19.09/1120 UT THE EARTH IS IN THE "-" SECTOR OF THE INTERPLANETA- RY MAGNETIC FIELD. 16, 17/09 THE SIGN OF SECTOR WAS VARIABLE. NEXT SEC- TOR BOUNDARY "-/+" IT CAN EXPECT 23.09. ---------------------------------------------------------------------- SEPTEMBER 14 15 16 17 18 19 20 SEPTEMBER Wus 000 000 000 000 000 000 000 F10.7 069 069 070 070 070 071 070 èbcg A1.1 2 1.8E+6 1.5å+6 1.3E+6 1.6E+6 3.2E+6 2.0E+6 2.1å+6 GOES Ie>2 733 164 144 192 288 161 156 pfu Ap 11 7 3 4 5 3 4 nô Dst nô KIOTO Amsc 10 6 4 4 5 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 HAVE NOT OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS NOT EXPECTED. ALL DAYS THE GEOMAGNETIC CONDITION REMAINED UNSETTLED AND QUIET. NEXT WEEK THE MOST PROBABLY QUIET AND UNSETTLED GEOMAGNETIC CONDI- TION WILL 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