Solar Terrestrial Activity Report [Image] Last update May 2, 2002 at 04:30 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update April 2, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update April 2, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update April, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was quiet on May 1. Solar wind speed ranged between 357 and 440 km/sec. Solar flare activity was low. Solar flux was 162.4, the planetary A index was 5 (3-hour K indices: 2112 2222, Boulder K indices: 2112 2111). Region 9914 rotated quietly over the northwest limb. Region 9915 decayed further and is rotating over the northwest limb. Region 9919 was quiet and stable. Region 9926 developed several new spots, however, the main penumbra lost much of its area. The region had mixed polarities for some time during the day but seems to have simplified again as of early on May 2. Region 9927 was quiet and stable, as was region 9928. New region 9930 emerged over the central meridian late on April 30, developed slowly on May 1, and currently seems to be in slow decay. New region 9931 emerged in the northeast quadrant. New region 9932 emerged in the southeast quadrant. New region 9933 rotated into view at the northeast limb. New large region 9934 rotated into view at the southeast limb. The region has a magnetic delta configuration in the large northernmost penumbra and possibly even at the southern edge of the southernmost penumbra. M class flares are likely and there is a possibility of a major flare. Flares and CMEs A total of 6 C class events were recorded on May 1. Region 99 The background x-ray flux is at the class B7 level. Coronal holes A well defined coronal hole in the northern hemisphere will rotate over the central meridian on May 2 but is 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 2-4. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9914 2002.04.19 1 N05W92 0050 HSX 9915 2002.04.21 4 N12W80 0150 CAO 9916 2002.04.21 S15W56 plage 9917 2002.04.22 S30W72 plage 9919 2002.04.22 1 N13W40 0060 HSX 9921 2002.04.23 N14W67 plage 9922 2002.04.23 N22W51 plage 9926 2002.04.27 11 N14W29 0070 DAO 9927 2002.04.29 6 S30E43 0080 CSO 9928 2002.04.29 5 N17E48 0120 DAO 9929 2002.04.30 N22E03 plage 9930 2002.05.01 10 N12W17 0030 CSO 9931 2002.05.01 8 N15E19 0030 CAO 9932 2002.05.01 3 S28E56 0040 CAO 9933 2002.05.01 1 N16E64 0090 HSX beta-gamma-delta 9934 2002.05.01 6 S18E73 0240 DAO area way too small, classification wrong Total number of sunspots: 56 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 2001.02 146.6 80.6 104.0 (-4.7) 2001.03 177.7 113.5 104.8 (+0.8) 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 (113.3 predicted, -0.8) 2001.11 210.6 106.5 (112.7 predicted, -0.6) 2001.12 235.1 132.2 (109.3 predicted, -3.4) 2002.01 226.6 113.9 (106.0 predicted, -3.3) 2002.02 205.0 108.0 (104.6 predicted, -1.4) 2002.03 179.5 98.1 (100.4 predicted, -4.2) 2002.04 189.8 195.0 (2) (94.5 predicted, -5.9) 2002.05 162.4 (1) 5.4 (2) 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]