Solar Terrestrial Activity Report [Image] Last update July 19, 2000 at 07:30 UTC. Minor update posted at 09:05 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 moderate on July 18. Solar wind speed was in the range 508-623 km/sec. The planetary A index was 13 (Kp: 3222 3344). Solar flux was 248.7 (corresponding to the measurement at 17h UTC, the 20h UTC measurement was higher due to the flare in region 9077). Region 9077 continued its decay and has only a minor chance of producing another major flare before rotating off the visible disk in a couple of days time. Region 9079 was quiet and stable. Regions 9080 and 9081 decayed slowly and were quiet. Region 9082 was mostly unchanged and quiet. Regions 9084 and 9085 did not change significantly and continue to be capable of producing minor M class flares. Region 9087 developed quickly and is currently the most interesting region on the disk. The region has developed a magnetic delta configuration. Major flares, possibly even an X class flare, are possible. Region 9088 developed slowly and could generate a minor M class flare. Region 9089 decayed into spotless plage. Region 9090 decayed slowly but remains a possible candidate for M class flare activity. Region 9091 decayed slowly and was quiet. Regions 9092, 9093 and 9094 were quiet and stable. Region 9095 developed slowly and could produce C class flares. New region 9096 rotated into view at the southeast limb. New region 9097 rotated partly into view at the northeast limb, the region could be capable of M class flaring. Comment added at 09:05 UTC on July 19: A long duration major M6.4 event peaked at 07:26 UTC. Its likely origin was in region 9087. A type IV sweep was recorded and a large CME is likely to have been generated. If the source was in region 9087 the CME will impact Earth, probably on July 21. Flares and CMEs A total of 6 C and 3 M class events were observed on July 18. Region 9077 produced an M1.9/2B flare at 05:15 UTC. This event was accompanied by a weak type IV sweep and a moderately strong type II sweep. A CME was likely produced as well but is not expected to influence the geomagnetic field. Region 9077 was the source of an M3.3 event at 19:45 UTC as well as a C4.1 flare at 23:00 UTC. Region 9087 generated a C9.3 flare at 07:23, a C6.4 flare at 17:36 and an M3.0/2N flare at 14:19 UTC. The latter event was associated with a weak type IV sweep and likely a CME which could reach Earth on July 21. Region 9097 was the source of a C2.8 flare at 10:57 UTC. The background x-ray flux is at the class C2 level. Coronal holes (No data available.) Forecast The geomagnetic field is expected to be quiet to active on July 19-21. 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 (caused by the X5 flare on July 14) 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 Location region numbered no. at Area Classification Comment sunspots midnight 9077 20000707 25 N18W58 0200 EAI beta-gamma 9078 20000707 S12W74 plage 9079 20000709 1 S25W51 0050 HSX 9080 20000709 4 N25W36 0020 BXO 9081 20000711 4 N04W22 0070 CSO 9082 20000711 8 S10W60 0050 DAO 9084 20000712 11 N20W41 0170 DAO 9085 20000712 21 N12W06 0300 EAO 9087 20000714 36 S12E13 0450 EAI beta-gamma-delta 9088 20000714 19 N22W23 0170 DAO 9089 20000715 N13E03 plage 9090 20000716 20 N11E46 0190 FAO beta-gamma 9091 20000716 4 S07E41 0070 CSO 9092 20000717 6 S25W27 0030 DSO 9093 20000717 2 S12W07 0010 CSO 9094 20000717 1 S25E50 0060 HSX 9095 20000717 8 N23E00 0050 DAO 9096 20000718 1 S13E71 0060 HSX 9097 20000718 2 N06E75 0200 DSO Total number of sunspots: 173 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 2000.07 204.4 (1) 137.5 (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]