Solar Terrestrial Activity Report [Image] Last update June 20, 2001 at 05:15 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 19. Solar wind speed ranged between 325 and 658 km/sec. Another disturbance began between 14 and 15h UTC. Since then solar wind speed has increased steadily from 430 to above 700 km/sec early on June 20. This steady increase suggests that the source of the disturbance is a coronal stream. Solar flare activity was low. Solar flux was 195.4, the planetary A index was 14 (3-hour K indices: 4322 3433, Boulder K indices: 4222 3333). Region 9498 decayed slowly and was spotless by the end of the day. Region 9500 decayed slowly and could become spotless today. Region 9501 was mostly unchanged and quiet. Region 9502 decayed slowly and was quiet. Region 9503 developed slowly adding many new spots. The region has major flare potential. Region 9504 was quiet and stable. An M class flare is possible. Region 9505 was quiet and stable. Region 9506 developed early in the day but decayed later on losing quite a few of its spots. Minor M class flares are possible. New region 9509 emerged in the southeast quadrant early in the day and rotated across the central meridian. Flares and CMEs A total of 2 C class events were recorded on June 19. Region 9504 generated a C2.0 flare at 18:26 UTC. Region 9501 was the source of a long duration C4.2 event peaking at 23:26 UTC. The background x-ray flux is at the class B8 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be unsettled to active on June 20. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to very 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 region numbered sunspots at Area Classification Comment midnight 9498 2001.06.10 3 N22W64 0010 AXX now spotless 9500 2001.06.11 3 N11W37 0010 BXO 9501 2001.06.11 9 S13W38 0150 CAO 9502 2001.06.12 7 S26W21 0020 BXO 9503 2001.06.13 56 N16W06 0550 FAI beta-gamma 9504 2001.06.13 8 N08W02 0390 CKO 9505 2001.06.14 3 N22E05 0030 DSO 9506 2001.06.14 35 N19E21 0360 FAO beta-gamma 9507 2001.06.15 N12W27 plage 9509 2001.06.19 8 S11W04 0030 DSO Total number of sunspots: 132 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) 2001.06 172.1 (1) 129.2 (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]