Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 17 - 23.02.2020, Forecast on 24.02 - 01.03.2020, Carrington Rotation 2227 (02,72.02.2020) Earth out of ecliptic (-4.1 - -4.6) deg. (S29 - N21 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED VERY LOW WITH A SPOTLESS VISIBLE DISK (38 SPOTLESS DAYS IN THE 2020). ESTIMA- TED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W=0(Wn=0). 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 - FOUR SOLAR FLARE (CLASS A), AND ONE CORONAL MASS EJECTION (21.02) HAVE BEEN OB- SERVED FOR 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 -------------------------------------------------------------------- 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. ---------------------------------------------------------------------- AFTER 15.02/20 UT THE IMF SECTOR SIGN WAS "-". NEXT WEEK THE BEHAVIOR OF THE SECTOR STRUCTURE SIGN WILL NOT CHANGE. FORECAST OF A SUSTAINABLE SECTOR BOUNDARY IS NOT POSSIBLE BECAUSE OF THE CONSTANT VARIABILITY OF THE IMF SECTOR SIGN IN THE CONDITIONS OF A DEEP MINIMUM CYCLE PHASE. ----------------------------------------------------------------------- FEBRUARY 17 18 19 20 21 22 23 FEBRUARY Wus 000 000 000 000 000 000 000 F10.7 071 071 071 070 071 072 070 èbcg 2 8.4E+6 1.8å+6 7.2E+6 4.1E+7 6.3E+7 7.9E+7 1.4E+8 GOES Ie>2 383 183 327 2786 2852 2370 3505 pfu Ap 7 14 14 8 14 9 5 nô Dst nô KIOTO Amsc 10 14 10 8 14 9 6 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 AT 20.02/1625 UT AND OBSERVED 20-23.02. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS EXPECTED 24-26.02. THE GEOMAGNETIC CONDITION AT MID-LATITUDES REMAINED UNSETTLED ALL DAYS. 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