Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 22 - 28.03.2021, Forecast on 29.03 - 04.04.2021, Carrington Rotation 2242 (14,23.04.2021) Earth out of ecliptic (-6.7 - -7.3) deg. (S35 - N25 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=12+4/-5 (Wn= 19+7/-8). ON VISIBLE SOLAR DISC THERE ARE 2 SMALL SUNSPOT GROUP HAVE BEEN OBSERVED. SINCE EARLY MARCH THE DOMINANT OF THE NOT- HERN HEMISPHERE. 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. 18 SOLAR FLARE OF X-RAY CLASS "B", 21 - CLASS "A", AND 10 CORONAL MASS EJECTIONS (22, 23, 25, 26.03) 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 - S15L351 S20L359 S25L254 S20L249 ~1.1% 29.03 2 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 26.03/0640 UT THE EARTH IS IN THE "-" SECTOR OF THE INTERPLA- NETARY MAGNETIC FIELD. THE SECTOR "+" OBSERVED AT 23-26.03. THE FOL- LOWING SECTOR BOUNDARY "-/+" IT CAN BE EXPECT 2.04. ---------------------------------------------------------------------- MARCH 22 23 24 25 26 27 28 MARCH Wus 012 026 026 024 024 011 011 F10.7 080 079 084 079 080 089 075 èbcg A4.8 A6.3 A4.6 á3.3 á3.5 A3.0 A2.4 GOES Sp 040 080 040 050 040 030 010 msh N 1 IMF - -/+ + + +/- - - DSCOVR Å>2 1.7E+8 3.0å+8 1.7E+8 2.0E+7 4.2E+7 2.7å+6 7.8E+6 GOES Ie>2 4050 10083 4501 5101 1507 888 727 pfu Ap 8 11 11 18 12 9 6 nô Dst nô KIOTO Amsc 8 11 10 14 7 6 9 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 21.03/1255 UT AND OBSERVED 21-26.03. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS NOT EXPECTED. GEOMAGNETIC CONDITION ALL THE PERIOD EXCEPT 25.03 REMAINED QUIET. 9-hour SUBSTORM OF INTENSITY (G1) ACCORDING TO THE CENTER IN BOUL- DER AND 6-hour INTENSITY (G0) ACCORDING TO IZMIRAN REGISTERED AT THE BEGINNING OF THE DAY 25.09 AS A CONSEQUENCE OF THE SLIDING EM- PACT OF THE RELEASE OF CORONAL MASS EJECTION 20.03. 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