Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 15 - 21.03.2021, Forecast on 22 - 29.03.2021, Carrington Rotation 2241, 2242 (17,94.03; 14,23.04.2021) Earth out of ecliptic (-6.0 - -6.6) deg. (S34 - N26 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= 9+5/-3 (Wn= 16+8/-4). ON VISIBLE SOLAR DISC THERE ARE 2 SMALL SUNSPOT GROUP 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=020+10/-10. FLARE ACTIVITY WAS AT LOW LEVEL. 12 SOLAR FLARE OF X-RAY CLASS "B", 13 - CLASS "A", AND 10 CORONAL MASS EJECTIONS (16, 18, 19, 20.03) 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 - S10L326 S25L353 S40L331 S31L321 ~3% 20.03 4 G0 SOHO,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. ---------------------------------------------------------------------- AFTER 18.03/1020 UT THE EARTH IS IN THE "-" SECTOR OF THE INTERPLA- NETARY MAGNETIC FIELD. THE SECTOR "+" OBSERVED AT 16-18.03. THE FOL- LOWING SECTOR BOUNDARY "-/+" IT CAN BE EXPECT 25.03. ---------------------------------------------------------------------- MARCH 15 16 17 18 19 20 21 MARCH Wus 024 023 012 012 014 012 012 F10.7 075 079 078 073 074 080 077 èbcg A4.0 A4.3 A3.8 á3.3 á3.1 A3.4 A5.2 GOES Sp 020 040 050 200 030 010 010 msh N 1 1 IMF - -/+ + +/- - - - DSCOVR Å>2 1.4E+8 1.8å+8 1.9E+8 5.5E+7 3.4E+7 1.8å+6 5.5E+7 GOES Ie>2 2291 3681 3873 1501 1198 500 2033 pfu Ap 6 3 2 4 12 29 24 nô Dst -8 -39 -30 nô KIOTO Amsc 6 4 6 3 6 25 22 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 14.03/1520 UT AND OBSERVED 14-19.03. NEW FLUX BEGAN 21.03/1255 UT AND OBSERVED 21/03 NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED 22-29.03. THE GEOMAGNETIC CONDITION REMAINED QUIET ALL THE PERIOD UNTIL 20. 03. MINOR MAGNETIC STORM (G2, Ams=29, dur.=24 h.) ACCORDING TO THE CENTER IN BOULDER DATA AND (G1, Ams= 31, ÄÌÉÔ.= 15 Þ.) ACCORDING IZMIRAN DATA AT 20 - 21.03 DUE TO EARTH's PASSAGE OF HIGH-SPEED STREAM FROM SOUTHERN CORONAL HOLE "-" POLARITY. ACCORDING TO BOTH CENTERS IN SECOND HALF OF 21.03 THE SUBSTORM (G1) DURATION 9 h. HA- VE BEEN ODSERVED. IN THE NEXT WEEK THE MOST PROBABLE IS EXPECTED A QUITE AND UNSET- TLED GEOMAGNETIC CONDITION. 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