Solar Terrestrial Activity Report [Image] Last update July 20, 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 Solar flare activity was high on July 19. Solar wind speed was in the range 459-664 km/sec. A solar wind shock was observed at 14:45 at SOHO, solar wind speed increased abruptly from 460 to 610 km/sec. The geomagnetic field was quiet to minor storm. The planetary A index was 15 (Kp: 3112 3445). Solar flux was 250. Region 9077 decayed fairly quickly and was mostly quiet. Further C class flares are possible before the region rotates off the visible disk early on July 21. Region 9079 was quiet and stable. Region 9080 developed quickly and could soon start to produce C flares and minor M flares. Region 9081 decayed slowly and was quiet. Region 9082 decayed into spotless plage. Region 9084 (near region 9080) developed slowly and could produce minor M flares. Region 9085 did not change significantly and continue to be capable of producing minor M class flares. Region 9087 developed further and is capable of producing an X class flare. A magnetic delta configuration is present in an intermediate trailing penumbra. Early on July 21 explosive development has occurred with the spot count increasing to nearly 100. Region 9088 lost a few spots but was otherwise mostly unchanged, a minor M class flare is possible. Region 9090 added a few spots and could produce M class flare activity. Region 9091 decayed slowly and was quiet. Regions 9092 and 9094 were quiet and stable. Region 9093 decayed into spotless plage. Region 9095 decayed slowly and was quiet. Region 9096 was quiet and stable. Region 9097 has a magnetic delta configuration within the leading penumbra and could be capable of producing a major flare. New region 9098 emerged in the southwest quadrant at a low latitude. New region 9099 rotated into view at the northeast limb. Flares and CMEs A total of 5 C and 1 M class events were observed on July 19. Region 9087 produced a C6.7 flare at 04:41, a C3.5 flare at 16:33 and a major long duration M6.4/3N event peaking at 07:26 UTC. A weak type IV sweep was observed in connection with the major flare. Although LASCO images ae currently unavailable, it is likely that a large CME was produced and that this CME could impact Earth on July 21 causing active to major or severe storm conditions. Region 9077 generated a C3.4 flare at 16:11 UTC. Region 9097 was the source of a C5.8/1F flare at 18:46 and a C3.6 flare at 21:58 UTC. July 18: Region 9087 generated an M3.0/2N flare at 14:19 UTC. This event was associated with a weak type IV sweep and likely a CME which could reach Earth on July 21. The background x-ray flux is at the class C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to minor storm on July 20 and quiet to major storm on July 21. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor to useless. 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 9077 20000707 11 N19W73 0080 FAO 9078 20000707 S12W87 plage 9079 20000709 1 S26W64 0060 HAX 9080 20000709 12 N24W54 0120 DAO 9081 20000711 1 N04W35 0070 HSX 9082 20000711 S10W73 plage 9084 20000712 7 N19W55 0280 DAO 9085 20000712 21 N14W18 0260 EAO 9087 20000714 51 S12W01 0510 FAC beta-gamma-delta 9088 20000714 12 N22W36 0170 DAO 9089 20000715 N13W10 plage 9090 20000716 28 N11E32 0190 FAO beta-gamma 9091 20000716 3 S06E27 0040 CAO 9092 20000717 3 S25W38 0030 CRO 9093 20000717 S12W20 plage 9094 20000717 1 S24E36 0050 HAX 9095 20000717 10 N24W14 0030 CRO 9096 20000718 2 S14E59 0070 DAO 9097 20000718 4 N06E66 0370 DAO beta-gamma-delta 9098 20000719 4 S02W21 0010 BXO 9099 20000719 1 N11E74 0050 HSX Total number of sunspots: 172 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 (112.5 predicted, +1.5) 2000.02 174.1 112.9 (115.3 predicted, +2.8) 2000.03 208.2 138.5 (118.5 predicted, +3.2) 2000.04 184.2 125.3 (120.6 predicted, +2.1) 2000.05 184.9 120.8 (121.4 predicted, +0.8) 2000.06 179.8 124.9 2000.07 206.8 (1) 148.5 (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]