Solar Terrestrial Activity Report [Image] Last update July 22, 2000 at 07:45 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 21. Solar wind speed was in the range 463-541 km/sec. The CMEs believed to have occurred in connection with flare activity on July 18 and 19 have failed to arrive. This shows how important the availability of LASCO image data is in forecasting geomagnetic storms. While LASCO images have been produced again since late on July 20, the movies have not been updated. The geomagnetic field was quiet to unsettled. The planetary A index was 9 (Kp: 3212 3323). Solar flux was 250.9. Region 9079 was quiet and stable and rotated over the west limb early on July 22. Region 9080 was quiet and is rotating off the visible disk. Region 9081 was quiet and stable. Region 9084 decayed slowly and was quiet. Region 9085 decayed and was quiet. Isolated minor M class flares are possible. Region 9087 lost some spots but is still very complex and could produce major flares. Region 9088 decayed slowly and was quiet. Region 9090 developed slowly and could produce an isolated major flare. Region 9091 decayed slowly and was quiet. Region 9092 decayed into spotless plage. Region 9094 was quiet and stable. Region 9095 was mostly unchanged and quiet, C class flares are possible. Region 9096 was quiet and stable. Region 9097 developed slowly but lost its magnetic delta configuration. The region could produce a major flare. Region 9098 decayed into spotless plage. Region 9099 was quiet and stable. Parts of an active region at the southeast limb has rotated into view, the region could be capable of minor M class flaring. Flares and CMEs A total of 9 C and 5 M class events were observed on July 21. Region 9087 produced a C4.0 flare at 03:12, a C6.0 flare at 04:41, a C6.3 flare at 08:59, an M1.9 flare at 10:50 and a C9.5 flare at 14:09 UTC. Region 9090 generated an M1.7/1N impulsive flare at 05:24, an impulsive M1.9/1N flare at 10:50, an impulsive major M5.5/2B flare at 14:37 (a weak type II sweep was detected. A weak CME may have been produced and could cause unsettled to minor storm conditions at Earth on July 24), a C4.3 flare at 20:21, a C9.0/1F flare at 20:47 and an M3.3 flare which began at 23:31 UTC and peaked at 00:01 UTC on July 22. Region 9097 was the source of a C6.9 flare at 18:37 UTC. July 20: Region 9087 generated a long duration M3.6/1F flare peaking at 10:06 UTC. A weak type IV sweep was recorded and an Earth directed CME may have been produced, if so the CME could arrive on July 23. Region 9090 was the source of a C5.7 flare at 16:39. This event was associated with a moderately strong type II sweep and a likely CME. Given the position of the flare the CME could well be Earth directed and cause unsettled to minor storm conditions on July 23. 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 to quiet to active on July 22-23, possibly with minor storm intervals on July 23. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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 9079 20000709 1 S28W87 0030 HSX 9080 20000709 2 N24W84 0100 DSO 9081 20000711 1 N05W62 0050 HSX 9084 20000712 1 N20W81 0090 HSX 9085 20000712 18 N14W48 0190 EAO beta-gamma 9087 20000714 66 S12W26 0790 FKC gamma-delta 9088 20000714 10 N23W64 0140 DAO 9089 20000715 N13W36 plage 9090 20000716 37 N12E05 0320 FKI beta-gamma-delta 9091 20000716 1 S06E04 0050 HSX 9092 20000717 S25W62 plage 9093 20000717 S12W49 plage 9094 20000717 3 S23E11 0040 CSO 9095 20000717 10 N22W42 0070 ESO 9096 20000718 4 S13E36 0060 CAO 9097 20000718 19 N06E42 0660 EKC beta-gamma 9098 20000719 S02W48 plage 9099 20000719 1 N13E50 0080 HSX Total number of sunspots: 174 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 (114.0 predicted, +3.0) 2000.02 174.1 112.9 (116.8 predicted, +2.8) 2000.03 208.2 138.5 (119.5 predicted, +2.7) 2000.04 184.2 125.3 (121.6 predicted, +2.1) 2000.05 184.9 120.8 (122.4 predicted, +0.8) 2000.06 179.8 124.9 2000.07 211.1 (1) 171.6 (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]