Solar Terrestrial Activity Report [Image] Last update July 30, 2000 at 06:20 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 low on July 29. Solar wind speed was in the range 459-497 km/sec. The geomagnetic field was unsettled to major storm. The planetary A index was 27 (Kp: 3346 5333). Solar flux was 153.2. Region 9090 was quiet and rotated off the visible disk. Region 9094 rotated over the west limb. Region 9096 was quiet and stable, the region is spotless early on July 30. Region 9097 decayed further and was quiet. Region 9099 was quiet and stable. Region 9100 could produce further C flares. Region 9101 was quiet and stable. Region 9102 decayed into spotless plage. Region 9103 developed slowly and could produce occasional C flares and perhaps a minor M flare. Regions 9104, 9105 and 9106 were quiet and stable. New region 9107 rotated partly into view at the southeast limb, the region could be capable of minor M class flaring. New region 9108 emerged in the southwest quadrant. New region 9109 emerged in the southeast quadrant. Flares and CMEs A total of 6 C class events were observed on July 29. Region 9107 produced a C1.2 flare at 02:44 UTC. Region 9100 generated a C2.3 flare at 07:15 UTC while region 9103 managed a C1.4 flare at 16:38 UTC. The background x-ray flux is at the class B5 level. Coronal holes An ill defined coronal hole in the northern hemisphere could rotate into a geoeffective position on July 30-August 1 and cause unsettled and active intervals on August 2-4. Forecast The geomagnetic field is expected to be quiet to unsettled on July 30-31. 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 no. Location at region numbered sunspots midnight Area Classification Comment 9090 20000716 1 N15W95 0060 HSX 9096 20000718 1 S12W72 0010 AXX 9097 20000718 13 N09W68 0120 DAO 9099 20000719 1 N17W54 0070 HSX 9100 20000722 3 S29W28 0090 CSO 9101 20000722 3 S13W31 0010 BXO 9102 20000725 S17E02 plage 9103 20000726 16 N08W11 0120 DAO 9104 20000726 1 S21E38 0120 HSX 9105 20000727 1 N14E54 0080 HSX 9106 20000727 5 S09W43 0030 CSO 9107 20000729 2 S19E69 0150 ESO 9108 20000729 2 S09W18 0010 BXO 9109 20000729 4 S07E40 0020 CRO Total number of sunspots: 53 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 2000.07 206.0 (1) 227.9 (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]