Solar Terrestrial Activity Report [Image] Last update May 4, 2002 at 02:30 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 3. Solar wind speed ranged between 378 and 457 km/sec. Solar flare activity was low. Solar flux was 179.1, the planetary A index was 7 (3-hour K indices: 2212 2332, Boulder K indices: 1221 2322). Region 9919 decayed slowly and will rotate over the northwest limb on May 5. Region 9926 decayed further and had only a single small spot left by the end of the day, the region is likely to become spotless early on May 4. Region 9927 decayed slowly and quietly. Region 9928 developed further early in the day, then began to decay. Region 9929 developed at a moderate pace and was quiet. Region 9930 decayed further and was spotless by early evening. Region 9931 developed slowly with minor mixing of polarities observed early on May 4. Region 9932 developed further and was mostly quiet. Region 9933 was quiet and stable. Region 9934 developed slowly with most of the development occurring in the southernmost spot section. This part of the region has a magnetic delta structure. The magnetic delta in the large northernmost penumbra appears to have disintegrated. An M class flare is still likely and the region is more active now than just a day ago. Region 9935 developed quickly during the first half of the day, then stabilized and has not changed much over the last 15 hours. Region 9936 developed slowly and quietly. New regions 9937 and 9938 rotated into view at the southeast limb. Early on May 4 a new spotted region is rotating into view at the northeast limb. Flares and CMEs A total of 6 C class events were recorded on May 3. Region 9932 produced a C2.0 flare at 04:01 UTC. Region 9926 was the source of a C3.3 flare at 06:47 UTC. Region 9934 generated a C3.9/1F flare at 18:09 and a C3.2 flare at 23:35 UTC. A C5.4 flare at 20:20 may have had its origin at or just behind the southeast limb. The background x-ray flux is at the class B8 level. Coronal holes A well defined coronal hole in the northern hemisphere rotated across the central meridian on May 2 but was likely too far to the north to be geoeffective. Another coronal hole, further east in the northern hemisphere, is currently poorly defined and will rotate into a geoeffective position on May 4-5. Forecast The geomagnetic field is expected to be quiet to unsettled on May 4-6. 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 9916 2002.04.21 S15W82 plage 9919 2002.04.22 1 N13W68 0050 HSX 9922 2002.04.23 N22W77 plage 9926 2002.04.27 4 N15W56 0040 DRO 9927 2002.04.29 2 S28E14 0030 HSX 9928 2002.04.29 17 N18E22 0130 DAO 9929 2002.04.30 12 N22W26 0080 DSO 9930 2002.05.01 3 N12W44 0020 CRO now spotless 9931 2002.05.01 13 N16W09 0120 DSO beta-gamma 9932 2002.05.01 10 S28E31 0160 DAO 9933 2002.05.01 4 N18E37 0100 CSO 9934 2002.05.01 21 S17E48 0580 EKI beta-gamma-delta 9935 2002.05.02 6 S19E16 0050 DSO 9936 2002.05.02 5 S16E27 0030 CRO 9937 2002.05.03 3 S09E68 0070 CSO 9938 2002.05.03 1 S04E72 0030 HSX Total number of sunspots: 102 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) 2002.05 170.2 (1) 19.2 (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]