Solar Terrestrial Activity Report [Image] Last update August 17, 2002 at 02:35 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update August 7, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update August 7, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update August 7, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent development The geomagnetic field was quiet to minor storm on August 16. Solar wind speed ranged between 470 and 678 km/sec. Solar flare activity was high. Solar flux was 213.8, the planetary A index was 17 (3-hour planetary K indices: 4353 3332, Boulder K indices: 3453 3332). Region 10061 rotated over the northwest limb. Region 10063 decayed further and was quiet. Region 10066 decayed slowly and quietly. Region 10067 decayed significantly and lost much of its penumbral area. Region 10068 decayed slowly and quietly. Region 10069 continued to develop, particularly in the northern section. X10+ proton flares are possible from this compact and complex region. Several magnetic delta structures are evident, including a very strong one in the central part of the extremely large main penumbra. Region 10072 rotated quietly over the southwest limb. Region 10076 was quiet and stable. Region 10078 decayed quickly and quietly. At the current rate of decay the region will soon become spotless. Region 10079 developed slowly and quietly. Region 10080 was mostly unchanged and quiet. New region 10081 rotated into view on August 15 and was finally numbered by SEC/NOAA. A new region emerged to the north-northwest of region 10076 but was not noticed by SEC/NOAA. Early on August 17 a new region is rotating into view at the southeast limb. Flares and CMEs A total of 3 C and 4 M class events was recorded on August 16. Region 10069 produced an M2.4/1N long duration event peaking at 06:11 UTC. A strong type II sweep was recorded as well, but this sweep was related to activity occurring in region 10061 at the northwest limb at the same time. No CME was observed after the M2 event but the activity in region 10061 resulted in a CME off the west limb and a minor increase in proton flux levels. Region 10069 was the source of a major M5.2 long duration event peaking at 12:32 UTC. A strong type II radio sweep was recorded and a fast full halo CME was observed in LASCO C3 within an hour after the event. A direct impact on Earth is expected sometime between 15h UTC today August 17 and noon on August 18. Active to severe geomagnetic storming is likely for 12-24 hours after the arrival of this solar storm. Region 10069 was the likely source of an M1.2 flare at 22:12 and an M1.9 flare at 23:33 UTC. A type IV radio sweep was recorded along with the latter flare and there may have been a CME as well. 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 active initially on August 17 and active to severe storm after a CME impact likely to occur either on August 17 or the first half of August 18. 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 10061 2002.08.03 1 N06W98 0080 HSX 10063 2002.08.06 6 N17W51 0100 DSO 10065 2002.08.08 S07W52 plage 10066 2002.08.09 17 N14W23 0090 DSO beta-gamma 10067 2002.08.10 32 N12W06 0200 ESI 10068 2002.08.10 3 S07W06 0050 ESO 10069 2002.08.11 37 S07E11 1750 EKC beta-gamma-delta 10070 2002.08.11 N08W68 plage 10072 2002.08.11 2 S18W91 0120 DSO 10073 2002.08.12 N16W65 plage 10074 2002.08.12 N24W53 plage 10075 2002.08.12 S11W24 plage 10076 2002.08.12 1 N12E25 0020 HSX 10077 2002.08.13 S18E22 plage 10078 2002.08.14 5 S13W39 0060 DSO area too large 10079 2002.08.14 12 S19E29 0140 DSO 10080 2002.08.14 9 N16E42 0170 DSO 10081 2002.08.16 2 N17E61 0050 DRO Total number of sunspots: 127 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 2001.07 131.3 81.8 111.7 (+1.9) 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 (114.0 predicted, -0.5) 2002.03 179.5 98.4 (110.3 predicted, -3.7) 2002.04 189.8 120.4 (104.5 predicted, -5.8) 2002.05 178.4 120.8 (100.0 predicted, -4.5) 2002.06 148.7 88.5 (95.5 predicted, -4.5) 2002.07 173.5 99.9 (90.6 predicted, -4.9) 2002.08 169.9 (1) 101.5 (2) (86.6 predicted, -4.0) 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]