Solar Terrestrial Activity Report [Image] Last update May 6, 2000 at 03:55 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update May 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update May 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update May 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update April 12, 2000)] Recent development The geomagnetic field was quiet to active on May 5. Solar wind speed ranged between 402 and 466 km/sec. Solar flare activity was moderate. Solar flux was 129.8, the planetary A index was 14 (3-hour K indices: 3243 3333, Boulder K indices: 3343 2423). Regions 8976 and 8978 were quiet and stable and are rotating over the west limb. Region 8980 is developing slowly and could produce C flares later today. Region 8981 was quiet and stable. Region 8982 could produce further C flares. Region 8983 was quiet and stable. New region 8984 emerged in the southeast quadrant. New region 8985 emerged in the northeast quadrant. New region 8986 emerged in the southeast quadrant. Flares and CMEs A total of 2 C flares and 1 M flare were recorded on May 5. Region 8982 produced a C2.7 flare at 02:28 UTC. Old region 8970 two days behind the southwest limb was the source of a long duration M1.5 event which peaked at 16:21 UTC. The flare would likely have been observed as an X class flare had it occurred on the visible disk. An impressive coronal mass ejection was seen off mainly the southwest limb. Old region 8971 a couple of days behind the northwest limb may have been the source of a CME off the northwest limb. The background x-ray flux is at the class B4 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on May 6-7 with the possibility of isolated active intervals. 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 8976 20000428 3 S12W82 0020 BXO 8978 20000428 2 N21W87 0030 BXO 8979 20000428 N21W44 plage 8980 20000428 4 S16W20 0010 BXO 8981 20000501 4 S22W25 0020 CSO 8982 20000503 3 S19W05 0010 CSO 8983 20000504 4 N24E44 0030 CSO 8984 20000505 5 S16E13 0010 BXO 8985 20000505 3 N13E51 0010 BXO 8986 20000505 4 S19E45 0010 BXO Total number of sunspots: 32 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.04 117.2 63.9 85.5 (+1.7) 1999.05 148.4 106.3 90.5 (+5.0) 1999.06 169.8 137.7 93.1 (+2.6) 1999.07 165.6 113.5 94.5 (+1.4) 1999.08 170.7 93.7 97.4 (+2.9) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.7 (+5.4) 1999.11 191.5 133.2 (109.8 predicted, +2.1) 1999.12 169.8 84.6 (108.2 predicted, -1.6) 2000.01 158.1 90.2 (108.6 predicted, +0.4) 2000.02 174.1 112.3 (112.0 predicted, +3.4) 2000.03 208.2 138.2 (115.8 predicted, +3.8) 2000.04 184.2 125.3 2000.05 142.4 (1) 18.4 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz.. 2) Unofficial, accumulated value. The official value 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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]