Solar Terrestrial Activity Report [Image] Last update April 15, 2002 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 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 to active on April 14. Solar wind speed ranged between 366 and 451 km/sec. Solar flare activity was moderate. Solar flux was 210.3, the planetary A index was 13 (3-hour K indices: 3322 4332, Boulder K indices: 3221 4322). Region 9893 was mostly unchanged and remains capable of producing a major flare. The region has been quite active over the last day. Region 9896 was quiet and stable, as was region 9899. Region 9900 decayed quickly and was spotless by noon. Region 9901 decayed further losing quite a few of its spots. In magnetograms it is impossible to separate the leading part of this region from region 9893. Region 9902 developed slowly and quietly. Region 9903 reemerged with a few spots but appears to be decaying again. Region 9905 was quiet and stable. Region 9906 developed further in the southern part of the trailing spots section. This is where a strong magnetic delta structure is located. The region is capable of producing major flares. Region 9907 decayed slowly and lost some penumbral area in the main part of the region. Lots of small spots are visible. Minor M class flares are possible. Region 9908 decayed further and could become spotless today. New region 9909 rotated into view at the northeast limb. Flares and CMEs A total of 9 C and 2 M class events were recorded on April 14. Region 9907 produced a C5.5 flare at 01:07, a C8.6 flare at 04:52, a C5.3 flare at 07:01 and a C4.4 flare at 20:56 UTC. Region 9893 generated a long duration M1.4/1F event peaking at 03:42, a C9.6 flare at 07:39 (associated with a strong type II radio sweep), a C7.3 flare at 21:25, a C7.2 flare at 22:29 (associated with a moderate type II radio sweep) and an M3.7 long duration event which began at 23:34 UTC and peaked at 00:14 (on April 15) UTC. A CME may have occurred along with the M3 event, however, LASCO images are not yet available. Region 9906 generated a C3.8 flare at 13:50 UTC. The background x-ray flux is at the class C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on April 15-17. 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 9893 2002.04.03 13 N20W67 0400 EAI beta-gamma-delta 9895 2002.04.05 N06W59 plage 9896 2002.04.05 1 S09W46 0090 HSX 9898 2002.04.06 S18W41 plage 9899 2002.04.06 4 N19W32 0190 CSO 9900 2002.04.07 3 S28W81 0040 BXO now spotless 9901 2002.04.07 14 N22W56 0180 DAO no obvious separation from region 9893 9902 2002.04.07 11 N13W11 0090 ESO 9903 2002.04.08 1 N15W02 0000 AXX 9904 2002.04.09 S14W69 plage 9905 2002.04.10 4 S14W55 0060 DSO 9906 2002.04.11 32 S15W02 0640 EKI beta-gamma-delta 9907 2002.04.11 25 S04E33 0330 DAI beta-gamma 9908 2002.04.12 7 N05W54 0020 CSO 9909 2002.04.14 1 N06E70 0130 HSX Total number of sunspots: 116 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) 2002.04 208.7 (1) 103.9 (2) (94.5 predicted, -5.9) 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]