Solar Terrestrial Activity Report [Image] Last update June 24, 2001 at 04:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update June 3, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update June 4, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update June 4, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update April 8, 2001)] Recent development The geomagnetic field was quiet to unsettled on June 23. Solar wind speed ranged between 392 and 563 km/sec. Solar flare activity was high. Solar flux was 206.2, the planetary A index was 8 (3-hour K indices: 2112 3332, Boulder K indices: 3111 3312). Region 9501 rotated quietly off the visible disk. Region 9503 decayed slowly and could produce minor M class flares. Region 9504 was quiet and stable. Region 9506 decayed slowly and quietly. Region 9509 decayed slowly and quietly. Region 9510 was quiet and stable. Region 9511 developed further but not as quickly as the day before. The magnetic delta appeared to be gone by midnight and the region is not currently likely to repeat the major flares it produced early in the day. Region 9512 developed further and was quiet. Minor M class flares are possible. Region 9513 developed slowly. The region may be capable of producing M class flares. Region 9514 was quiet and stable. Magnetograms indicate that this region is part of region 9513. New region 9515 emerged fairly quickly in the southeast quadrant. New region 9516 rotated into view at the northeast limb. Flares and CMEs A total of 7 C, 2 M and 1 X class events were recorded on June 23. Region 9511 was the source of all flares produced during the day. A major flare, an impulsive M5.6/1N event was observed at 00:15 UTC. This was followed by an X1.2/1B flare at 04:08 UTC, less than 10 hours after the first flare noted from this region. There was no apparent CME associated with either of these major flares. Other events were a C8.0 flare at 02:13, a C6.2 flare at 05:09, an M1.3/1N flare at 06:26, a C6.8/1F flare at 08:34, a C4.0 flare at 13:04, a C7.0 flare at 14:33, a C3.6 flare at 17:28 and finally a C2.2 flare at 19:59 UTC. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole to the south of region 9511 will rotate into a geoeffective position on June 24. Forecast The geomagnetic field is expected to be quiet to unsettled on June 24-25. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor. Coronal holes (1) Coronal mass M and X class flares (3) ejections (2) [Coronal hole indicator][CME indicator] [M and X class flare indicator] 1) Effects from a coronal hole could reach earth within the next 5 days. 2) Material from a CME is likely to impact earth within 96 hours. 3) There is a possibility of either M or X class flares within the next 48 hours. Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability. Active solar regions (Recent map) Solar Date Actual no. Location at region numbered sunspots midnight Area Classification Comment 9500 2001.06.11 N12W88 plage 9501 2001.06.11 1 S13W90 0030 HAX 9502 2001.06.12 S27W69 plage 9503 2001.06.13 20 N16W61 0310 FAO beta-gamma 9504 2001.06.13 5 N08W56 0260 CKO 9505 2001.06.14 N21W47 plage 9506 2001.06.14 13 N18W34 0270 FAO 9507 2001.06.15 N12W79 plage 9509 2001.06.19 5 S09W60 0060 CSO 9510 2001.06.20 3 S07W78 0060 CSO 9511 2001.06.20 22 N10E13 0110 DAO beta-gamma 9512 2001.06.21 17 S22E05 0130 EAO 9513 2001.06.21 13 N23E56 0160 FAO beta-gamma 9514 2001.06.22 3 N17E54 0040 HSX 9515 2001.06.23 5 S06E46 0070 CAO 9516 2001.06.23 1 N12E70 0090 HAX Total number of sunspots: 108 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 (+3.1) 2000.04 184.2 125.5 120.8 (+0.9) cycle 23 sunspot max. 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 170.1 119.7 (+1.0) 2000.08 163.0 130.5 118.6 (-1.1) 2000.09 182.1 109.7 116.2 (-2.4) 2000.10 167.4 99.4 114.5 (-1.7) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 (111.1 predicted, -1.7) 2001.01 166.6 95.6 (107.6 predicted, -3.5) 2001.02 146.6 80.6 (102.8 predicted, -4.8) 2001.03 177.7 113.5 (99.2 predicted, -3.6) 2001.04 177.7 108.2 (98.0 predicted, -1.2) 2001.05 147.1 97.3 (97.3 predicted, -0.7) 2001.06 177.4 (1) 158.3 (2) (94.6 predicted, -2.7) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-40% less. This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ Do you know about the survey which will be held this Summer among the listeners of WWV and WWVH? There is information about this survey at 16 minutes past the hour on WWV and at 47 minutes past the hour on WWVH. If you want to participate send an email with your name and address. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]