Solar Terrestrial Activity Report [Image] Last update June 28, 2000 at 04:10 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 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update June 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update June 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update April 12, 2000)] Recent development The geomagnetic field was unsettled to active on June 27. Solar wind speed ranged between 478 and 582 km/sec under the influence of a coronal stream. Solar flare activity was low. Solar flux was 178.6, the planetary A index was 18 (3-hour K indices: 4333 3344, Boulder K indices: 4332 3343). Region 9046 could produce additional C class flares while at the west limb today. Region 9049 was quiet and stable, the region will rotate off the visible disk late today. Region 9054 was quiet and stable, minor M class flares are possible. Regions 9055, 9056 and 9057 were quiet and stable. Region 9058 developed slowly and could generate isolated minor M class flares. Region 9059 was quiet and stable, as were regions 9060 and 9061. Region 9062 developed further and could produce C and minor M class flares. Region 9063 developed quickly, C flares are likely and there is a possibility of a minor M class flare as well. New region 9064 emerged just to the south of region 9058. Flares and CMEs A total of 7 C flares were observed on June 27. Region 9062 produced a long duration C9.3/2N event peaking at 12:55 UTC. Region 9046 generated a C1.9 flare at 14:32, a C1.7 flare at 16:49 and a C3.2 flare at 21:05 UTC. A large CME was observed off the northwest limb and the north pole following a filament eruption near the northwest limb. The eruption began at 09:36 and was, for this type of event, unusually intense at its peak. The background x-ray flux is at the class B6 level. Coronal holes A well defined coronal hole in the southern hemisphere was in a geoeffective position on June 23-26. Forecast The geomagnetic field is expected to be quiet to active on June 28. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 at region numbered sunspots midnight Area Classification Comment 9046 20000614 1 N20W90 0070 HSX 9049 20000616 1 S35W77 0030 HSX 9051 20000617 N13W70 plage 9053 20000619 N04W58 plage 9054 20000620 22 N12W32 0210 EAI beta-gamma 9055 20000621 2 N20W08 0060 HSX 9056 20000621 1 S13W11 0220 HSX 9057 20000622 3 N14E07 0260 CHO 9058 20000623 12 S13W68 0320 EKO 9059 20000623 3 N16W22 0010 BXO 9060 20000624 4 S33E22 0020 BXO 9061 20000624 1 S15E31 0050 HSX 9062 20000625 13 S18E48 0260 DKO 9063 20000626 8 N25E29 0080 DAO beta-gamma 9064 20000627 5 S20W67 0030 DRO Total number of sunspots: 76 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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) 1999.11 191.5 133.2 110.9 (+3.2) 1999.12 169.8 84.6 (111.2 predicted, +0.3) 2000.01 158.1 90.2 (112.4 predicted, +1.2) 2000.02 174.1 112.3 (115.8 predicted, +3.4) 2000.03 208.2 138.2 (119.6 predicted, +3.8) 2000.04 184.2 125.3 (121.7 predicted, +2.1) 2000.05 184.9 120.8 2000.06 181.3 (1) 172.3 (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]