Solar Terrestrial Activity Report [Image] Last update June 25, 2000 at 05:25 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 24. Solar wind speed ranged between 453 and 651 km/sec, steadily decreasing during the second half of the day. Solar flare activity was low. Solar flux was 168.3, the planetary A index was 17 (3-hour K indices: 5453 1222, Boulder K indices: 4343 2123). Region 9042 was quiet and will rotate behind the west limb today. Region 9046 decayed slowly and could produce C flares. Region 9049 was mostly unchanged and quiet. Further C class fares are possible. Region 9050 was quiet and rotated off the visible disk. Region 9054 was mostly quiet and has been developing slowly, occasional C class flares are possible. Regions 9055, 9056 and 9057 were quiet and stable. Region 9058 is developing at a moderate pace and may become capable of minor M class flaring later today is development continues. Region 9059 developed slowly and was quiet. New region 9060 rotated into view at the southeast limb. New region 9061 rotated partly into view at the southeast limb. Flares and CMEs A total of 2 C flares were observed on June 24. Region 9049 produced a C1.2 flare at 08:04 UTC. An optically uncorrelated C1.3 flare was observed at 20:19 UTC. Region 9042 produced an M2.5 flare while at the west limb at 01:14 UTC on June 25. June 23: A filament to the north and east of region 9051 erupted at 07:13 UTC in LASCO-EIT images. Parts of the filament was over the central meridian at the time of the eruption. An apparently full halo CME was observed later in LASCO C2 images. The CME could impact Earth on June 26, however, the expected presence of a coronal stream at that time will likely mean that the CME will add little to the ongoing geomagnetic activity. There is a chance the CME could arrive just before the coronal stream in which case initial activity could reach minor storm levels. The background x-ray flux is at the class B6 level. Coronal holes A well defined coronal hole in the southern hemisphere will be in a geoeffective position on June 23-26. Forecast The geomagnetic field is expected to be quiet to active on June 25 and quiet to minor storm on June 26-27. 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 9042 20000612 9 N22W89 0120 DSO 9046 20000614 13 N21W48 0150 DSO 9047 20000615 S27W82 plage 9049 20000616 16 S36W34 0110 ESI 9050 20000617 2 S07W92 0060 CSO 9051 20000617 N13W31 plage 9053 20000619 N04W19 plage 9054 20000620 10 N12E11 0040 DSO 9055 20000621 1 N19E30 0110 HSX 9056 20000621 2 S14E28 0250 HAX 9057 20000622 1 N13E46 0240 HAX 9058 20000623 7 S14W29 0050 DSO 9059 20000623 7 N15E17 0040 DSO 9060 20000624 1 S34E59 0000 AXX 9061 20000624 1 S15E72 0050 HSX Total number of sunspots: 70 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 2000.06 181.8 (1) 153.6 (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]