Solar Terrestrial Activity Report [Image] Last update September 6, 2002 at 04:45 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update September 3, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 3, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 3, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent development The geomagnetic field was quiet to unsettled on September 5. Solar wind speed ranged between 407 and 466 km/sec Solar flare activity was low. Solar flux was 175.2, the planetary A index was 10 (3-hour planetary K indices: 3322 3232, Boulder K indices: 3422 2323). Region 10094 developed a few trailing spots but was otherwise quiet and stable. Region 10095 decayed further slowly losing a significant amount of penumbral area in all parts of the region. Several trailing spots disappeared. Region 10096 developed early in the day, then began to decay slowly. Region 10097 decayed quickly and was quiet. Region 10098 decayed slowly and lost its last spot late in the day. Region 10099 decayed slowly and quietly, the region could become spotless within 2-3 days. Region 10100 was quiet and stable. Region 10101 decayed further and had a single small spot left at midnight, the region will likely become spotless today. Region 10102 decayed slowly and quietly. Region 10103 developed slowly and quietly. A minor M class flare could soon become a possibility. Flares and CMEs A total of 8 C class events was recorded on September 5. Region 10095 produced a C1.5 flare at 00:15 UTC. Region 10096 generated a C5.1 flare at 12:39 and a C8.6 flare at 20:45 UTC. A filament eruption just east of region 10102 at 16:24 UTC triggered a long duration C5.2 event from region 10102 peaking at 17:10 UTC. A full halo CME was associated with this event. The CME expanded quickly eastwards and slowly over the west limbs. Although Earth will not receive a direct hit, parts of the CME are likely to reach Earth on September 8. The background x-ray flux is at the class B7 level. Coronal holes A possible coronal hole in the southern hemisphere will rotate into a geoeffective position on September 8. Forecast The geomagnetic field is expected to be quiet to unsettled on September 6-7 and quiet to minor storm on September 8 due to a likely CME impact. 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 10091 2002.08.27 N06W80 plage 10093 2002.08.29 S16W78 plage 10094 2002.08.29 6 S19W27 0120 CAO area too large, 10095 2002.08.29 46 N08W17 0500 FKI was near 0350 at midnight. 10096 2002.08.30 22 S16W02 0220 EAI 10097 2002.08.31 13 N12W34 0110 DAO 10098 2002.08.31 2 S10E11 0010 BXO now spotless 10099 2002.09.01 4 S05W30 0030 CSO 10100 2002.09.01 10 S20E18 0130 CSO 10101 2002.09.01 1 N02E17 0010 HSX 10102 2002.09.02 1 N08E26 0010 HSX 10103 2002.09.03 20 N15E46 0120 DAO Total number of sunspots: 105 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2001.08 162.9 106.4 113.6 (+1.8) 2001.09 233.2 150.7 114.1 (+0.5) 2001.10 207.6 125.5 114.0 (-0.1) 2001.11 210.6 106.5 115.5 (+1.5) 2001.12 235.1 132.2 114.6 (-0.9) 2002.01 226.6 114.1 113.5 (-1.1) 2002.02 205.0 107.4 114.7 (+1.2) 2002.03 179.5 98.4 (113.2 predicted, -1.5) 2002.04 189.8 120.4 (108.7 predicted, -4.5) 2002.05 178.4 120.8 (104.2 predicted, -4.5) 2002.06 148.7 88.5 (99.7 predicted, -4.5) 2002.07 173.5 99.9 (94.9 predicted, -4.8) 2002.08 183.6 116.4 (90.8 predicted, -4.1) 2002.09 174.4 (1) 37.3 (2) (87.1 predicted, -3.7) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-45% 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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News]