Solar Terrestrial Activity Report [Image] Last update August 2, 2001 at 03:55 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 1. Solar wind speed ranged between 452 and 685 km/sec, peaking early in the day, then decreasing slowly for the remainder of the day. Solar flare activity was low. Solar flux was 120.2, the planetary A index was 12 (3-hour K indices: 3233 3322, Boulder K indices: 3234 3312). Region 9557 decayed slowly and was quiet. Region 9561 was mostly unchanged and produced a couple of flares. Region 9562 was quiet and stable. Region 9563 was quiet and stable most of the day, some growth was evident by the end of the day. New region 9564 emerged in the northwest quadrant. New region 9565 emerged in the northeast quadrant but appeared to be spotless by late evening. New region 9566 emerged near the northeast limb and is developing at a moderate pace. Flares and CMEs A total of 2 C class events were recorded on August 1. Region 9561 produced a C2.4 flare at 03:50 UTC and a couple of sub flares. The background x-ray flux is at the class B2 level. Coronal holes A small, well placed coronal hole in the southern hemisphere will be in a geoeffective position on August 2. Forecast The geomagnetic field is expected to be quiet to unsettled on August 2-4. A coronal stream will likely cause unsettled to active conditions on August 5. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 9553 2001.07.23 N14W85 plage 9555 2001.07.24 S09W51 plage 9557 2001.07.26 12 S19W03 0080 EAO 9559 2001.07.27 S22W51 plage 9560 2001.07.29 N18E07 plage 9561 2001.07.30 9 S12E37 0110 EAO 9562 2001.07.30 7 N05E44 0120 DAO 9563 2001.07.31 1 N24E44 0000 AXX 9564 2001.08.01 2 N14W40 0020 CRO 9565 2001.08.01 3 N04E22 0010 BXO 9566 2001.08.01 4 N17E63 0040 DSO Total number of sunspots: 38 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 (+3.1) 2000.04 184.2 125.5 120.8 (+0.9) cycle 23 sunspot max. 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 170.1 119.7 (+1.0) 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) 2001.08 120.2 (1) 3.5 (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]