Solar Terrestrial Activity Report [Image] Last update May 4, 2000 at 04:05 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 3. Solar wind speed ranged between 465 and 612 km/sec. Solar flare activity was moderate. Solar flux was 137.3, the planetary A index was 15 (3-hour K indices: 3342 2443, Boulder K indices: 2233 2542). Region 8970 rotated off the visible disk producing a minor M flare while at the limb. Region 8971 is rotating over the west limb and could produce an M flare while at and just behind the limb today. Regions 8976, 8977, 8978, 8980 and 8981 were quiet and stable. New region 8982 emerged in the southeast quadrant. An active region rotated into view at the northeast limb and will be numbered today. Flares and CMEs A total of 2 C flares and 1 M flare were recorded on May 3. Region 8970 produced an M1.1 flare at 23:10 UTC. The background x-ray flux is at the class B5 level. Coronal holes A coronal hole in the southern hemisphere was likely in a geoeffective position on May 1-2. Forecast The geomagnetic field is expected to be quiet to unsettled on May 4-5 with a chance 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 8970 20000420 1 S14W92 0170 HAX 8971 20000421 6 N18W85 0370 CKO beta-gamma 8975 20000423 S25W80 plage 8976 20000428 1 S12W63 0040 HSX 8977 20000428 3 S13W75 0020 CRO 8978 20000428 2 N20W61 0060 HRX 8979 20000428 N21W18 plage 8980 20000428 6 S16E05 0020 BXO 8981 20000501 10 S22E03 0030 CSO 8982 20000503 4 S20E19 0000 BXO Total number of sunspots: 33 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.04 117.2 63.9 85.4 (+1.6) 1999.05 148.4 106.3 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 94.4 (+1.4) 1999.08 170.7 93.7 97.5 (+3.1) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.4 107.7 (+5.4) 1999.11 191.5 132.7 (110.3 predicted, +2.6) 1999.12 169.8 86.4 (109.0 predicted, -1.3) 2000.01 158.1 90.2 (109.4 predicted, +0.4) 2000.02 174.1 112.3 (112.9 predicted, +3.5) 2000.03 208.2 138.2 (116.6 predicted, +3.7) 2000.04 184.2 125.3 2000.05 149.3 (1) 11.0 (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]