------------------------------------------------------------------- THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON FEBRUARY 2021 HAS MADE Wfeb. = 5.0 8.3(n) THAT GIVES FOR 6 MONTH (2020, AUGUST) OF DEVELOPMENT CURRENT 25 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*july = 5.5 9.3 - in new system W*june = 4.7 7.8 - 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 Febuary 2021 (68 observatories): 1.. 0 6.. 0 11.. 0 16.. 0 21.. 10 26.. 19 2.. 9 7.. 0 12.. 0 17.. 0 22.. 16 27.. 17 3.. 7 8.. 3 13.. 0 18.. 10 23.. 35 28.. 13 4.. 0 9.. 2 14.. 0 19.. 9 24.. 38M 5.. 0 10.. 0 15.. 0 20.. 9 25.. 34 Minimum : 0 on 1, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17 [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 FEBUARY 2021, AND SMOOTHES ON 2020, AUGUST 2020 F10.7feb. = 74.3 F*10.7aug.= ÈÈÈ THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON FEBUARY 2021, AND SMOOTHES ON 2021, AUGUST 2020 Ap feb.= 9.5 Ap*aug = xxx --------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 22 - 28.02.2021, Forecast on 01 - 07.03.2021, Carrington Rotation 2241 (18,62.02.2021) Earth out of ecliptic (-4.4 - -4.8) deg. (S33 - N29 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED ON VERY LOW LEVEL. ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUNSPOT NUM- BER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W=14+6/-6 (Wn= 23+10/-10. ON VISIBLE SOLAR DISC THERE ARE 3 DMALL SUNSPOT GRO- UP HAVE BEEN OBSERVED. NEXT WEEK SUNSPOT ACTIVITY WILL BE ON VERY LOW LEVEL. WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATI- ONAL SYSTEM (old) FOR NEXT WEEK IS W=010+10/-10. FLARE ACTIVITY WAS AT LOW LEVEL. 49 SOLAR FLARE OF X-RAY CLASS "C", 49-CLASS "B", AND 11 CORONAL MASS EJECTIONS (22-24, 26-28. 02) 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 CH - S08L252 S40L245 S42L248 S30L270 ~2.5% 01.03 1 - SOHO... * - 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. ---------------------------------------------------------------------- AFTER 261.02/1330 UT THE EARTH IS IN THE "+" SECTOR OF THE INTERPLA- NETARY MAGNETIC FIELD. THE FOLLOWING SECTOR BOUNDARY "+/-" IT CAN BE EXPECT 2.03. ---------------------------------------------------------------------- FEBRUARY 22 23 24 25 26 27 28 FEBRUARY Wus 026 031 033 031 016 014 013 F10.7 076 078 081 080 080 079 078 èbcg A2.1 A4.2 A5.3 á7.3 á5.9 A5.5 A5.2 GOES Sp 040 100 150 200 170 190 120 msh N 2 1 IMF - ~ - - -/+ + + DSCOVR Å>2 3.0E+8 3.8å+8 2.5E+8 2.0E+7 1.1E+8 5.5å+7 1.1E+8 GOES Ie>2 9239 14236 22370 971 6369 1628 2733 pfu Ap 17 12 21 13 11 6 8 nô Dst nô KIOTO Amsc 15 11 20 12 8 7 8 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 21.02/0535 AND OBSERVED 21 - 28.02, EXEPT 25.02. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED 1.03. MINOR MAGNETIC STORM (G0, Ams=27, dur.= 12 h.) ACCORDING TO THE CENTER BOULDER DATA AND SUBSTORM INTENSITY (G1) DUR.= 9 h.) AC- CORDING IZMIRAN DATA MARKED 24.02 IN RESPONSE TO GLANCING BLOW OF CORONAL MASS EJECTION FROM SOLAR FILAMENT EJECTION 20.02. IN THE OTHER DAYS, THE GEOMAGNETIC CONDITION WAS UNSETTLED AND QUIET. IN THE NEXT WEEK THE MOST PROBABLE IS EXPECTED A QUITE AND UNSET- TLED GEOMAGNETIC CONDITION. HOWEVER, 1.03 ACCORDING IN BOULDER CENTER DATA, AN INTENSIVE (G2) SUBSTORM DURING 9 h. WAS MARKED. ACCORDING IZMIRAN DATA IN THE SAME HOURS REGISTERED 6 h. SUBSTORM (G1). 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