Solar Terrestrial Activity Report [Image] Last update August 16, 2001 at 04:35 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 1, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update August 1, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update August 1, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update July 27, 2001)] Recent development The geomagnetic field was quiet to unsettled on August 15. Solar wind speed ranged between 364 and 469 km/sec A major proton event is in progress. Proton fluxes began to increase very early on August 16 and the above 100 MeV proton flux has so far reached 28 pfu while the above 10 MeV flux so far has reached 460 pfu. The source of the proton event must have been a very large flare in a region several days behind the southwest limb. An impressive full halo CME was observed in LASCO C3 images early today. Solar flare activity was low. Solar flux was 146.7, the planetary A index was 9 (3-hour K indices: 2332 2332, Boulder K indices: 2221 2322). Regions 9570 and 9571 decayed slowly and were quiet. Region 9573 decayed further and was quiet. Region 9574 decayed significantly and was mostly quiet. Region 9575 was quiet and stable. Region 9577 reemerged quickly with several spots. Region 9578 decayed and was quiet, the region appeared to be spotless by the end of the day. Region 9579 developed slowly and was quiet. Region 9580 was quiet and stable. New region 9581 emerged in the southwest quadrant. New region 9582 emerged slowly at the northeast limb. Flares and CMEs A total of 2 C class events were recorded on August 15. Region 9574 produced a C1.0 flare at 12:42 UTC. August 14: A long duration C2.3 event peaked at 12:42 UTC. Its source was an extensive filament eruption in the northwest quadrant fairly near the central meridian. A bright full halo CME was observed in LASCO C3 images. This CME should impact Earth sometime between late on August 16 and 18h UTC on August 17 causing active to major storm conditions, possibly with severe storm conditions at high latitudes. The background x-ray flux is at the class B5 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on August 16 and quiet to major storm on August 17 with a chance of isolated severe storm intervals at high latitudes. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor to useless because of a polar cap absorption event in progress. 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 9570 2001.08.05 1 S12W60 0140 HAX 9571 2001.08.06 1 N06W43 0020 HAX 9572 2001.08.07 N16W83 plage 9573 2001.08.08 5 S08W23 0040 CAO 9574 2001.08.10 13 S04W66 0190 EAO 9575 2001.08.11 1 N12E20 0130 HAX 9577 2001.08.12 7 N13W61 0050 CSO beta-gamma 9578 2001.08.12 4 S08W53 0020 CSO 9579 2001.08.14 8 S19W22 0050 DSO 9580 2001.08.14 1 N25E61 0140 HAX 9581 2001.08.15 1 S28W09 0020 HRX 9582 2001.08.15 3 N32E73 0040 CAO Total number of sunspots: 45 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.7 2000.08 163.0 130.5 118.6 (-1.1) 2000.09 182.1 109.7 116.2 (-2.4) 2000.10 167.4 99.4 114.5 (-1.7) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 112.1 (-0.7) 2001.01 166.6 95.6 108.8 (-3.3) 2001.02 146.6 80.6 (103.3 predicted, -5.5) 2001.03 177.7 113.5 (99.7 predicted, -3.6) 2001.04 177.7 108.2 (98.5 predicted, -1.2) 2001.05 147.1 97.3 (97.9 predicted, -0.6) 2001.06 173.0 134.0 (95.1 predicted, -2.8) 2001.07 131.3 82.2 (93.2 predicted, -1.9) 2001.08 151.5 (1) 76.1 (2) (93.8 predicted, +0.6) 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 25-40% 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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ Do you know about the survey which will be held this Summer among the listeners of WWV and WWVH? There is information about this survey at 16 minutes past the hour on WWV and at 47 minutes past the hour on WWVH. If you want to participate send an email with your name and address. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]