------------------------------------------------------------------- THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON MARCH 2020 HAS MADE Wmar. = 3.2 5.4(n) THAT GIVES FOR 129 MONTH (2019, OCTOBER) OF DEVELOPMENT CURRENT 24 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*oct. = 1.6 2.6 - new system W*sep. = 1.9 3.1 - 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 24 cycles SA. THE BEGINNING OF 24 SOLAR CYCLE - I 2009 with W*=1.8; (2.2) THE TIME OF THE CURRENT CYCLE MAXIMUM - IV 2014, - Wmax =82; (116.4) THE END OF 24 SOLAR CYCLE (THE POINT OF MINIMUM) - I - VI 2020; OTHER SC FORECAST: SM : SIDC classical method : based on an interpolation of Waldmeier's standard curves; the estimated error ranges from 7% (first month) to 35% (last month) - February 2020; NOAA - December 2019. The last two, in my opinion, are inadequate, since such short, low SCs were not observed. The observed magnetic structures corresponding SC 25 (>43 on October 2019) can be seen http://www.solen.info/solar/cycle25_spots.html Provisional daily International Sunspot Numbers for APRIL 2020 (63 observatories): 1.. 13 6.. 0 11.. 0 16.. 0 21.. 0 26.. 14 2.. 13 7.. 0 12.. 0 17.. 0 22.. 0 27.. 29 3.. 13 8.. 0 13.. 0 18.. 0 23.. 0 28.. 15 4.. 14 9.. 0 14.. 0 19.. 0 24.. 0 29.. 24 5.. 0 10.. 0 15.. 0 20.. 0 25.. 6 30.. 20 Minimum : 0 on 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 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 APRIL 2020, AND SMOOTHED ON 2019, OCTOBER F10.7apr. = 69.5 F*10.7oct.= 69.5 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON APRIL 2020, AND SMOOT- HES ON 2019, OCTOBER Ap apr. = 5.3 Ap*oct. =6.2 ------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 27.04 - 03.05.2020, Forecast on 04 - 11.05.2020, Carrington Rotations 2230 (24,65.04.2020) Earth out of ecliptic (-4.9 - -4.5) deg. (S35 - N20 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED VERY LOW. SPOT- LESS VISIBLE DISK HAVE BEEN OBSERVED BEFORE 28.04 AND 1-3.05 (93 SPOTLESS DAYS IN THE 2020). ESTIMATED, MOST LIKELY WEEK- LY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTER- NATIONAL SYSTEM (old) FOR PERIOD W = 6+15/-6 (Wn= 10+25/-10). THREE SOLAR SUNSPOT GROUP OF CURRENT (1) AND NEXT SOLAR CYC- LES HAVE BEEN OBSERVED ON VISIBLE SOLAR DISC. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WAS ON VERY LOW LEVEL. 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 THE VERY LOW LEVEL, BUT 22 SOLAR FLARE OF "A" AND "B" CLASSES, ONE SOLAR FILAMENT EJECT WITH VERY SLOW CME AND SOME MORE THREE CORONAL MASS EJECTIONS (29.04 AND 3.05) HAVE BEEN OBSERVED OF THE PERIOD. ------------------------------------------------------------------- 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 27.04 on end of the day N-hemisph. ? óíå -------------------------------------------------------------------- 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 CH* + N10L355 S05L017 S15L007 N07L315 10.8% 27/04 R1 SDO,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 12.03/20 UT THE IMF SECTOR SIGN WAS "-" BUT 3.05/12 UT THE EARTH POSSIBLE PASSED -/+ SECTOR BOUNDARY. THE BEHAVIOR OF THE SEC- TOR STRUCTURE SIGN WILL NOT CHANGE. THE REAL PROVISION OF THE NEXT SECTOR BOUNDARY IS NOT IMPOSSIBLE, MAY BE BECAUSE OF A DEEP MINIMUM CONDITIONS (TOPIC FOR STUDY!!!). ------------------------------------------------------------------ APRIL 27 28 29 30 01 02 03 MAY Wus 012 000 024 035 000 000 000 F10.7 069 069 070 070 070 069 069 èbcg >A1.0 2 1.9E+6 1.9å+6 2.4E+6 2.7E+6 1.5E+6 1.5E+6 1.4å+6 GOES Ie>2 164 249 166 179 191 178 138 pfu Ap 7 6 3 2 6 5 5 nô Dst nô KIOTO Amsc 8 5 3 4 5 5 5 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- OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS NOT EXPECTED. THE GEOMAGNETIC CONDITION CHANGED FROM UNSETTLED TO QUITE. 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