Solar Terrestrial Activity Report [Image] Last update July 18, 2000 at 07:30 UTC. /Because of my vacation the text on this page will be updated occasionally until July 31. No charts will be produced until normal daily updates start on August 4/ [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update July 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update July 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update July 1, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update April 12, 2000)] Recent development Summary July 13-17: Lots of flaring occurred during this period. Region 9077 produced the second largest flare of this solar cycle, an X5.7/3B event at 10:24 UTC on July 14. Strong type II and IV sweeps were recorded. The flare occurred while the region was near the central meridian and the resulting halo coronal mass ejection was extremely impressive and fast (estimated at above 2000 km/sec). The flare was also a huge proton producing event which quickly contaminated most space based solar instruments, particularly ACE measurements were rendered useless. The above 100 MeV proton flux peaked at 408 pfu on July 14 while the above 10 MeV peaked at an extremely high value of 24000 pfu at 12:30 UTC on July 15. The transit time for the CME was an astonishingly short 28 hours as the most intense geomagnetic storm of this solar cycle began near 15h UTC on July 15. Extremely severe storming (K index 9) was observed for the remainder of the day and the main part of the disturbance was over by 06 UTC on July 16. A very strong polar cap absorption event was recorded on Earth and totally ruined radio based communication at high latitudes. The planetary A index for July 15 reached 152. Current situation: Region 9077 remains capable of producing a major flare. The region was the source of an M1.9/2B flare at 05:15 on July 18. A type IV sweep was recorded and a CME was likely produced. Region 9087 produced the 2 M class events on July 17 (including an M2.4/1N event at 20:27 UTC which was accompanied by a strong type II sweep and a possibly geoeffective CME) and may be capable of major flaring. Region 9090 is another potential source of highly energetic flares. Flares and CMEs (This section not updated). The background x-ray flux is at the class C2-C3 level. Coronal holes (No data available.) Forecast The geomagnetic field is expected to be quiet to active with occasional minor storming on July 18-20. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is useless and will remain that way for some days until after the effects of the PCA event has subsided. 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 9077 20000707 32 N18W47 0320 FKC beta-gamma 9078 20000707 S12W61 plage 9079 20000709 1 S25W37 0050 HSX 9080 20000709 9 N26W23 0070 BXO 9081 20000711 8 N04W11 0090 CSO 9082 20000711 11 S09W47 0040 DSO 9084 20000712 10 N21W26 0160 DAO 9085 20000712 23 N15E08 0300 EAO beta-gamma 9087 20000713 26 S12E28 0250 DAI beta-gamma 9088 18 N21W10 0120 DAO 9089 1 N13E16 0000 AXX 9090 17 N12E58 0250 FSI beta-gamma 9091 5 S06E54 0110 CAO 9092 5 S26W14 0030 BXO 9093 3 S11E07 0010 CSO 9094 20000717 1 S25E62 0080 HSX 9095 20000717 5 N22E11 0020 BXO Total number of sunspots: 175 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.06 169.8 137.7 93.1 (+2.6) 1999.07 165.6 113.5 94.3 (+1.2) 1999.08 170.7 93.7 97.5 (+3.2) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.8 (+5.5) 1999.11 191.5 133.2 110.9 (+3.1) 1999.12 169.8 84.6 111.0 (+0.1) 2000.01 158.1 90.1 (110.9 predicted, -0.1) 2000.02 174.1 112.9 (113.7 predicted, +2.8) 2000.03 208.2 138.5 (117.9 predicted, +4.2) 2000.04 184.2 125.3 (120.0 predicted, +2.1) 2000.05 184.9 120.8 (120.8 predicted, +0.8) 2000.06 179.8 124.9 2000.07 201.8 (1) 126.4 (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]