Solar Terrestrial Activity Report [Image] Last update June 15, 2000 at 04:50 UTC. Minor update posted at 21:34 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 quiet to minor storm on June 14. Solar wind speed ranged between 412 and 490 km/sec. A disturbance began at approximately 06h UTC when the interplanetary magnetic field suddenly strengthened and swung moderately southwards. Further strengthening of the IMF occurred later in the day but then with a mostly northwards polarity. During the final hours of the day and early on June 15 the IMF was moderately to strongly southwards which resulted in minor storming on all latitudes. There was only a fairly small increase in solar wind speed after the start of the disturbance, wind density was at times much higher than normal. Solar flare activity was low. Solar flux was 200.6, the planetary A index was 23 (3-hour K indices: 4243 4455, Boulder K indices: 3233 4445). Region 9026 was quiet and stable has rotated over the west limb. Region 9032 reemerged with a couple of spots, the region will rotate off the visible disk today. Region 9033 decayed slowly and was quiet, the region could produce a minor M flare. Region 9034 was quiet and stable, as were regions 9035, 9036, 9037 and 9038. Region 9039 decayed slowly and was quiet. Region 9040 was quiet and stable. Region 9041 was mostly unchanged and has minor M class flaring potential. Region 9042 has fairly tight magnetic gradients and should continue to produce C flare. Isolated M flares are possible. Region 9043 was quiet and stable. Region 9044 decayed into spotless plage. New region 9045 emerged in the southeast quadrant. New region 9046 rotated partly into view at the northeast limb, this region appears to be large and could produce M flares. Comment added at 21:34 UTC on June 15: Region 9041 produced a long duration M1.8/2N event peaking at 19:57 UTC. Earlier today, at 15:13 UTC, neighboring region 9033 generated a C6.6 flare. This event was accompanied by a weak type II sweep. At 21:28 a C9.9 flare was observed, its origin is not certain as I write this. The geomagnetic field has been under the influence of a coronal stream since approximately 23h UTC on June 14, solar wind speed peaked near 700 km/sec at 15h UTC today. Flares and CMEs A total of 4 C class flares were observed on June 14. Region 9042 produced a C4.5 flare at 01:49 UTC. Region 9033 generated a C2.6 flare at 04:24 and a C1.8/1F flare at 13:49 UTC. The latter event was accompanied by a moderately strong type II sweep. A filament eruption was observed in the northeast quadrant to the west and northwest of region 9040, the eruption started at 04:24. The background x-ray flux is at the class B9 level. Coronal holes No obvious coronal holes are approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to minor storm on June 15 and quiet to unsettled on June 16. 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 9026 20000601 1 N22W90 0090 HSX 9030 20000603 N13W88 plage 9032 20000605 2 S19W81 0010 HRX 9033 20000605 35 N24W36 0320 FKI beta-gamma 9034 20000606 2 S09W40 0070 HSX 9035 20000608 3 S16W67 0020 CRO 9036 20000608 8 S23W03 0240 DAO 9037 20000610 14 N20W04 0150 DAO 9038 20000611 6 N16W71 0030 CRO 9039 20000611 10 N09W51 0080 DAO 9040 20000611 6 N17E33 0100 CAO 9041 20000611 11 N18W51 0130 DAO 9042 20000612 20 N21E56 0570 EKI beta-gamma 9043 20000613 3 N25W12 0010 BXO 9044 20000613 S24W40 plage 9045 20000614 6 S15E19 0010 BXO 9046 20000614 1 N15E82 0090 HSX Total number of sunspots: 128 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 2000.06 179.4 (1) 81.7 (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]