Solar Terrestrial Activity Report [Image] Last update June 7, 2000 at 03:55 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 active on June 6. Solar wind speed ranged between 417 and 505 km/sec. Solar flare activity was high. Solar flux was 186.4, the planetary A index was 16 (3-hour K indices: 4334 3432, Boulder K indices: 3334 3512). Region 9017 was quiet and has rotated out of view at the southwest limb. Region 9024 developed quickly and could produce C flares and perhaps a minor M flare. Region 9026 was mostly unchanged as a very complex region. Further X class flares are possible as a strong magnetic delta still exists within the main penumbra. Region 9028 was quiet and stable, some slow development is evident early on June 7. Region 9030 decayed into spotless plage. Region 9031 was quiet and stable. C class flares are possible. Region 9032 was quiet and mostly stable. Region 9033 has minor M class flaring potential and was mostly quiet. New region 9034 rotated into view at the southeast limb. Flares and CMEs A total of 6 C flares, 2 M flares and 2 X flares were observed on June 6. Region 9024 produced a C4.6/1F flare at 00:43 UTC. Apart from that region 9026 was the source of all other flares recorded during the day. A C2.8 flare occurred at 08:16, a C2.4 flare was observed at 08:51, a C1.8 flare at 11:27, a C7.5/2N flare at 12:18, an M2.7/3B flare at 13:19, a major X1.1/3B flare at 13:39, a major M7.1 flare at 14:01 and finally the spectacular X2.3/2B long duration event peaking at 15:25 UTC. The latter event was accompanied by a strong type IV sweep and a moderately strong type II sweep. A very large, fast and magnificent full halo coronal mass ejection was observed in LASCO C2 images from 15:54 UTC. This CME will impact Earth sometime between the evening of June 7 and late on June 8 and could cause the most significant geomagnetic storm so far in solar cycle 23. Major to very severe storming is likely and isolated extremely severe storm intervals (K=9) are possible. A minor proton flux enhancement was observed starting very early on June 7. June 5: Region 9024 produced a C4.5/1F flare starting at 03:10 and peaking at 03:25 UTC. This triggered an interesting filament eruption which was observed starting at 03:12 UTC in LASCO EIT images. The eruption spread eastwards from region 9024 and almost to the central meridian. A partial halo coronal mass ejection was seen in LASCO C2 images from 04:06 UTC and covered parts of the southeast limb, the south pole, the southwest limb and the northwest limb. There should be a 50-60% chance of a terrestrial impact on June 8 with geomagnetic activity expected to range between unsettled and minor storm. A moderately strong type II sweep and a weak type IV sweep was observed as well. [This CME could be overtaken by the much larger CME observed on June 6.] The background x-ray flux is at the class C1 level. Coronal holes A small coronal hole in the southern hemisphere was in a geoeffective position on June 5 and could cause a few unsettled to active intervals on June 8 or 9. [This coronal stream will not be noticed due to a large CME probably catching up with it before it reaches Earth.] Forecast The geomagnetic field is expected to be initially quiet to unsettled on June 7. A CME impact will occur late in the day or on June 8. Major to very severe storming is likely from the time of the impact and for 12-36 hours afterwards. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9017 20000524 1 S13W84 0180 HSX 9022 20000528 S22W55 plage 9024 20000529 11 S13W58 0100 ESO 9026 20000601 22 N20E10 0800 FKI beta-gamma-delta 9027 20000601 N25W63 plage 9028 20000601 4 N13W38 0020 CSO 9030 20000603 N12E17 plage 9031 20000604 5 S32W65 0110 CSO 9032 20000605 4 S16E25 0030 CSO 9033 20000605 5 N22E63 0290 FSO 9034 20000606 1 S10E68 0060 HSX Total number of sunspots: 53 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 2000.06 171.4 (1) 26.1 (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]