Solar Terrestrial Activity Report [Image] Last update June 28, 2001 at 04:40 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 active on June 27. Solar wind speed ranged between 370 and 496 km/sec, generally decreasing after noon. Solar flare activity was low. Solar flux was 147.9, the planetary A index was 10 (3-hour K indices: 4421 2222, Boulder K indices: 3421 1121). Region 9506 rotated off the visible disk. Region 9511 decayed and was mostly quiet. Region 9512 decayed considerably and had only a few spots left early on June 28. Region 9513 decayed slowly and quietly. Region 9514 decayed slowly and was quiet. Region 9515 was mostly unchanged and quiet. Region 9516 was quiet and stable. New region 9518 emerged in the southeast quadrant at an unusually high latitude. New region 9519 emerged in the northeast quadrant and appeared to be decaying early on June 28. New region 9520 emerged briefly in the southeast quadrant, it is now spotless. Flares and CMEs A total of 7 C class events were recorded on June 27. Region 9512 produced a C1.5 flare at 03:54 and a C2.2 flare at 22:50 UTC. Region 9518 generated a C1.8 flare at 07:43 UTC while region 9511 managed a C1.8 flare beginning at 23:56 and peaking at 00:00 UTC. The background x-ray flux is at the class B5 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on June 28-29. 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 9506 2001.06.14 2 N18W87 0120 CSO 9511 2001.06.20 10 N10W37 0060 DSO 9512 2001.06.21 18 S23W50 0150 EAI beta-gamma 9513 2001.06.21 24 N22E05 0150 FSO 9514 2001.06.22 6 N16E00 0040 CSO 9515 2001.06.23 12 S07W09 0090 DSO 9516 2001.06.23 3 N11E14 0120 CSO 9517 2001.06.25 S14W85 plage 9518 2001.06.27 5 S48E45 0070 DSO beta-gamma 9519 2001.06.27 4 N17E23 0020 BXO 9520 2001.06.27 1 S10E25 0000 AXX Total number of sunspots: 85 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) 2001.06 176.8 (1) 184.8 (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]