Solar Terrestrial Activity Report [Image] Last update May 6, 2002 at 04:05 UTC. Minor update posted at 18:31 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update May 3, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update May 3, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update May 3, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was quiet to unsettled on May 5. Solar wind speed ranged between 318 and 360 km/sec. Solar flare activity was low. Solar flux was 180.0, the planetary A index was 8 (3-hour K indices: 1112 3332, Boulder K indices: 1112 2202). Region 9926 was spotless for the second consecutive day. SEC/NOAA somehow managed to observe a single spot. Region 9927 decayed and was spotless by early afternoon. Region 9928 decayed further losing a significant amount of penumbral area. Region 9929 decayed and lost nearly all spots outside of the leading penumbra. Region 9931 decayed further and had only a few spots left by the end of the day. Region 9932 decayed further losing several spots and a significant amount of penumbral area. Region 9933 was quiet and stable. Region 9934 simplified as it lost its magnetic delta structure. New trailing spots emerged. An M class flare is possible. Region 9935 decayed further and was spotless by late afternoon. Region 9936 decayed and could become spotless later today or tomorrow. Region 9937 developed slowly and may be capable of minor M class flaring. Regions 9938, 9939 and 9940 were quiet and stable. New region 9941 emerged in the southeast quadrant on May 4 and has not developed much since then. New region 9942 emerged in the northeast quadrant. The region is already decaying and could soon become spotless. New region 9943 rotated into view at the southeast limb. Comment added at 18:31 UTC on May 6: A coronal stream began to influence the geomagnetic field after 13h UTC. Current solar wind speed is near 400 km/sec and the geomagnetic field as at unsettled to active levels. A fairly large penumbra is rotating into view at the southeast limb. Otherwise most of the spotted regions are decaying slowly. Flares and CMEs A total of 6 C class events were recorded on May 5. Region 9934 produced a C4.8 flare at 08:08, a C3.0 flare at 12:25 and a C1.6 flare at 18:11 UTC. Region 9937 generated a C1.9 flare at 14:46 UTC. Region 9943 was the source of a C2.6/1F flare at 19:14 UTC. 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 May 6-8. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 9926 2002.04.27 1 N13W82 0040 HSX actually spotless 9927 2002.04.29 4 S28W13 0020 BXO now spotless 9928 2002.04.29 15 N18W05 0090 DAO spot number too high 9929 2002.04.30 13 N22W53 0210 DAO spot number too high 9930 2002.05.01 N12W70 plage 9931 2002.05.01 10 N16W37 0070 CAO spot number too high 9932 2002.05.01 16 S28E05 0100 EAI classification wrong 9933 2002.05.01 3 N18E12 0100 HSX 9934 2002.05.01 36 S17E21 0540 EKI beta-gamma 9935 2002.05.02 7 S19E11 0020 BXO now spotless 9936 2002.05.02 10 S17E01 0040 CAO spot number too high 9937 2002.05.03 10 S09E42 0210 DAI 9938 2002.05.03 1 S05E46 0030 HSX 9939 2002.05.04 1 N17E52 0050 HSX 9940 2002.05.04 2 N13E55 0040 HSX 9941 2002.05.05 10 S22E09 0050 DAO spot number too high 9942 2002.05.05 4 N22E34 0020 CSO 9943 2002.05.05 4 S11E63 0050 CAO Total number of sunspots: 147 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 2001.04 177.7 107.7 107.5 (+2.7) 2001.05 147.1 96.6 108.6 (+1.1) 2001.06 173.0 134.0 109.8 (+1.2) 2001.07 131.3 82.2 111.7 (+1.9) 2001.08 162.9 106.8 113.6 (+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 (114.7 predicted, +0.7) 2001.12 235.1 132.2 (112.5 predicted, -2.2) 2002.01 226.6 113.9 (109.8 predicted, -2.7) 2002.02 205.0 108.0 (108.4 predicted, -1.4) 2002.03 179.5 98.1 (104.2 predicted, -4.2) 2002.04 189.8 120.4 (98.3 predicted, -3.9) 2002.05 176.0 (1) 38.2 (2) (93.8 predicted, -4.5) 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]