Solar Terrestrial Activity Report [Image] Last update June 3, 2000 at 05:00 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 unsettled on June 2. Solar wind speed ranged between 392 and 463 km/sec. Solar flare activity was high. Solar flux was 187.2 (strongly influenced by the long duration major flare in region 9026), the planetary A index was 10 (3-hour K indices: 2332 2233, Boulder K indices: 2331 1322). Region 9017 decayed slowly and was mostly quiet. An area with opposite polarity is forming just ahead of the lead spot and could lead to increased flare activity. An isolated M class flare is possible. Regions 9022 and 9023 were quiet and stable. Region 9024 is developing slowly and could soon become capable of C class flaring. Region 9025 was quiet and has rotated off the visible disk. Region 9026 is developing slowly. The region has a complex magnetic mix of positive and negative polarity areas and could produce further major flares, possibly even proton flares, over the next few days. Region 9027 was quiet and stable. Region 9028 was mostly quiet and stable. Flares and CMEs A total of 3 C flares and 4 M flares were observed on June 2. Region 9028 was the origin of a long duration C2.4 event peaking at 09:39 UTC. The flare may have been triggered by a filament eruption extending from the southern edge of the region to the solar equator. LASCO C3 images indicate a very weak full halo CME from approximately 10:30 UTC. This CME could impact Earth on June 5 but will likely not cause a significant disturbance, unsettled to active intervals are possible. Region 9026 was the source of the remainder of the significant flare activity. The region produced a long duration M1.2/1F event peaking at 04:14, an M4.1/1N flare at 06:59 UTC (this event was associated with a moderately large CME off the east limb) and a C5.1 flare at 12:27 UTC. A long duration major M7.6/2B flare peaked at 19:38 UTC. This event was associated with a very large coronal mass ejection off most of the east limb and the north pole. An M3 flare was observed just before 22h and a very long duration C8 event began at 23h and peaked at 00:30 UTC on June 3. The latter event is still decaying. May 31: A filament eruption was observed over the central meridian in the northern hemisphere starting at 06:48 UTC. A nearly full halo coronal mass ejection was observed in LASCO C2 images from 08:06 UTC, the only part of the disk where material motion was not detected was over the central west limb. A terrestrial impact is likely on June 3. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole in the southern hemisphere could rotate into a geoeffective position on June 5. Forecast The geomagnetic field is expected to be initially quiet to unsettled on June 3. A CME impact is possibly later in the day and could cause unsettled to minor storm conditions. Another CME impact is possible on June 5 and will likely not cause activity above the unsettled to active level. 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 9016 20000524 N26W70 plage 9017 20000524 17 S12W36 0570 EKO beta-gamma 9020 20000527 N04W74 plage 9021 20000528 N04W49 plage 9022 20000528 3 S22W03 0010 BXO 9023 20000529 3 S01W66 0020 BXO 9024 20000529 8 S14W00 0030 DSO 9025 20000531 1 N16W91 0000 AXX 9026 20000601 8 N20E61 0720 EKO beta-gamma 9027 20000601 3 N21W10 0010 BXO 9028 20000601 3 N08E12 0000 BXO Total number of sunspots: 46 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) 1999.11 191.5 133.2 110.9 (+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 2000.06 167.6 (1) 8.5 (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]