Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 28.09 - 04.10.2020, Forecast on 05 - 11.10.2020, Carrington Rotation 2235, 2236(07,74.09; 05,01.10.2020) Earth out of ecliptic (7.1 - 6.5) deg. (S20 - N35 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED ON VERY LOW LEVEL THE VISIBLE SOLAR DISK WAS SPOTLESS BEFORE 9.10 (203 SPOTLESS DAYS AT 2020). ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERI- OD W=0 (Wn=0). ON VISIBLE SOLAR DISK TWO SMALL SUNSPOT GROUPS OF 25 SOLAR CYCLE. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WAS ON VERY LOW LEVEL. VISIBLE SOLAR DISK WITH HIGH PROBABILITY WILL BE SPOTLESS. LI- KELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR NEXT WEEK IS W=010+10/-10. FLARE ACTIVITY WAS AT VERY LOW LEVEL. 27 SOLAR FLARE OF LOW X- RAY CLASS "A", 1 SOLAR FILAMENT EJECTA AND 3 CORONAL MASS EJE- TIONS 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 -------------------------------------------------------------------- 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 Sp/craft * - 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 7.10/03 UT, THE EARTH IS IN THE "-" SECTOR OF THE INTERPLANE- TARY MAGNETIC FIELD. THE FOLLOWING THE NEXT SECTOR BOUNDARY "-/+" IT CAN EXPECT 14.10. ---------------------------------------------------------------------- OCTOBER 05 06 07 08 09 10 11 OCTOBER Wus 000 000 000 000 024 026 026 F10.7 072 072 071 072 073 074 073 èbcg A2.1 A1.6 2 1.2E+9 2.7å+4 6.2E+7 2.8E+7 2.7E+7 4.2E+7 2.0å+7 GOES Ie>2 42682 1331 3236 1081 770 1243 780 pfu Ap 8 8 4 3 2 2 3 nô Dst nô KIOTO Amsc 12 4 5 3 2 3 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 BEGUN AT 24.09/1540 UT AND OBSERVED AT 28.09-8.10. NEXT ELECTRON FLUX HAVE BEGUN AT 10.10/1720 UT AND ONE DAY HAVE BEEN OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED 5-12.10. ALL DAYS THE GEOMAGNETIC CONDITION REMAINED QUIET AND UNSETTLED. NEXT WEEK THE MOST PROBABLY QUIET AND UNSETTLED GEOMAGNETIC CONDI- TION 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