Dear users, Happy New Year 2021, May 2021 bring a lot of joy, discovery and success in the study of solar activity and solar-terrestrial relations Yours faithfully, V.N. Ishkov ------------------------------------------------------------------- THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON DECEMBER 2020 HAS MADE Wnov. = 13.1 21.8(n) THAT GIVES FOR 6 MONTH (2020,JUNE) OF DEVELOPMENT CURRENT 25 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*june = 4.7 7.8 - in new system W*may = 3.4 5.6 - in new system On July 1, 2015 Centre in Brussels moved to a new system of calcu- lation the relative number of sunspots and practically all of the values were replaced throughout the numbered series of Wolf numbers (see link). While there is addictive, I recalculated (0.6) to the old system, but only W*, and present below the new values for the minimum and maximum of 25 cycles SA. THE BEGINNING OF 25 SOLAR CYCLE - I 2020 with W*=1.3; (1.8n) MAXIMUM OF THE CURRENT 25 CYCLE - VI 2024 - Wmax =90-100; (150n) THE END OF 25 SOLAR CYCLE (THE POINT OF MINIMUM) - I - VI 2031; Provisional daily International Sunspot Numbers for December 2020 (68 observatories): 1.. 50M 6.. 22 11.. 11 16.. 13 21.. 11 26.. 32 31.. 32 2.. 46 7.. 20 12.. 11 17.. 12 22.. 11 27.. 31 3.. 43 8.. 13 13.. 11 18.. 7 23.. 23 28.. 29 4.. 39 9.. 13 14.. 13 19.. 0m 24.. 27 29.. 30 5.. 36 10.. 12 15.. 19 20.. 0m 25.. 29 30.. 29 [The daily value W in old system close to true (in a minimum phase) can be received, multiplying by k = 0.6]. THE MONTHLY MEAN OF OBSERVED RADIO FLUX OF THE 10 cm (2800 MHz) ON DECEMBER 2020, AND SMOOTHES ON 2020, JUNE 2020 F10.7dec. = 86.8 F*10.7june= 73.2 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON DECEMBER 2020, AND SMOOTHES ON 2020, JUNE 2020 Ap dec.= 4.8 Ap*june = xxx --------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 28.12.2020 - 03.01.2021, Forecast on 04 - 11.01.2021, Carrington Rotation 2239(25,94.12.2020) Earth out of ecliptic (0.5 - -0.9) deg. (S30 - N30 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED ON VERY LOW LEVEL. AFTER 3.01 THE SUN WAS SPOTLESS (1 DAY AT 2021). ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUNSPOT NUMBER IN THE INTERNA- TIONAL SYSTEM (old) FOR PERIOD W=13+3/-13 (Wn= 21+5/-21). ON THE VISIBLE DISK OF THE SUN TWO SMALL SUNSPOT GROUPS HAVE BEEN OBSER- VED. NEXT WEEK SUNSPOT ACTIVITY WILL BE AT VERY LOW LEVEL. THE VISIBLE SOLAR DISC WILL BE SPOTLESS VERY LIKELY. 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 LEVELS. 17 SOLAR FLARE OF LOW X- RAY CLASS "B", CONSEQUENTIAL RELEASE TWO EJECTIONS OF SOLAR FILA- MENTS SOUTH-WEST OF ACTIVE REGION ON S17W70 2.01/<1136 UT AND 6 CORONAL MASS EJECTIONS (29, 30.12, 1-2.01) 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 02.01 <1136 SE-Ë×ÁÄÒÁÎÔ ~10 CME/1136 1148 -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT VERY LOW AND 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 óî - S10L009 S12L010 S22L003 S15L359 0.1% 28.12 1 - SDO... CH + S10L276 S15L270 S25L272 S12L293 0.9% 05.01 1 - SDO... * - 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 3.01/0920 UT, THE EARTH IS IN THE "+" SECTOR OF THE INTERPLANETA- RY MAGNETIC FIELD. THE FOLLOWING THE NEXT SECTOR BOUNDARY "+/-" IT CAN BE EXPECT 06.01 (SSBN-passage). ---------------------------------------------------------------------- DECEMBER 28 29 30 31 01 02 03 JANUARY Wus 026 026 026 025 023 022 000 F10.7 087 084 083 081 080 082 080 èbcg á7.2 á5.6 B5.7 á4.5 á4.7 á4.8 á4.6 GOES Sp 300 310 210 210 190 120 000 msh N IMF - - - - - - -/+ DSCOVR Å>2 1.5E+6 2.1å+7 1.3E+7 2.0E+7 2.1E+7 4.2E+7 4.3å+7 GOES Ie>2 737 405 405 560 533 503 629 pfu Ap 7 7 9 3 4 2 2 nô Dst nô KIOTO Amsc 8 6 7 4 4 0 2 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 NOT OB- SERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS NOT EXPECTED. ALL DAYS THERE WERE UNSETTLED AND QUITE GEOMAGNETIC CONDITION HAVE BEEN OBSERVED. IN THE NEXT WEEK THE MOST PROBABLE IS EXPECTED A QUITE AND UNSETT- LED GEOMAGNETIC CONDITION. HOWEVER, THERE IS A SMALL CHANCE OF GEO- MAGNETIC DISTURBANCE GROWTH ON 5 - 6.01 DUE TO THE ARRIVAL OF CMEs FROM DOUBLE FILAMENT EJECTA 2.01 AND THE EARTH PASSAGE OF A HIGH- VELOCITY STREAM FROM SMALL CORONAL HOLE OF THE SOLAR SOUTHERN HEMI- SPHERE. THE PROBABILITY OF A MINOR MAGNETIC STORM IS NOT MORE THAN 20%. 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