Solar Terrestrial Activity Report [Image] Last update February 3, 2002 at 05:45 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 2, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2002)] [Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 2002)] Recent development The geomagnetic field was quiet to minor storm on February 2. Solar wind speed ranged between 331 and 439 km/sec. The interplanetary magnetic field swung fully southwards just after 01h UTC and this caused active to minor geomagnetic storm conditions for the next 12 hours. SEC/NOAA reports a sudden impulse at 05:58 UTC. This was not observed as a sudden impulse at other magnetometers, it was rather a part of the development of the ongoing disturbance. Moreover there was no solar wind shock associated with this. SEC/NOAA speculated that the disturbance was associated with a behind the limb M3 flare in region 9787 on January 31. There is no evidence for such a connection, and in the absence of significantly higher solar wind speeds and a solar wind shock, such speculation cannot be comprehended. Solar flare activity was low. Solar flux was 240.6, the planetary A index was 18 (3-hour K indices: 3354 4332, Boulder K indices: 3453 3322). Region 9800 decayed further and has only a minor chance of producing an M class flare. Region 9801 was quiet and stable. Region 9802 began to decay but should still be capable of M class flaring. Region 9806 was quiet and stable. Region 9807 decayed quietly, a minor M class flare is still possible. Region 9808 decayed slowly and quietly. Region 9809 was quiet and stable, as was region 9810. New region 9811 rotated partly into view at the southeast limb. New region 9812 emerged in the northwest quadrant. Early on February 3 a spotted region is rotating into view at the northeast limb. Flares and CMEs A total of 5 C class events were recorded on February 2. Region 9802 produced a C2.2 flare at 15:36 and a C2.9 flare at 20:03 UTC. The background x-ray flux is at the class C1 level. Coronal holes A well defined trans equatorial coronal hole will rotate into a geoeffective position on February 3. Forecast The geomagnetic field is expected to be quiet to unsettled on February 3-5. A coronal stream is likely to cause unsettled to active geomagnetic conditions on February 6-7, possibly with a few minor storm intervals as well. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to very 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 9799 2002.01.23 S24W75 plage 9800 2002.01.25 28 N10W44 0490 EAI beta-gamma 9801 2002.01.25 5 S04W29 0110 CSO 9802 2002.01.26 55 S14W18 0660 FKC beta-gamma-delta 9804 2002.01.28 S17W39 plage 9805 2002.01.28 N14E00 plage 9806 2002.01.28 4 N11E03 0050 DSO 9807 2002.01.30 16 S27E38 0210 EAI 9808 2002.01.31 6 N16E28 0050 CAO 9809 2002.01.31 3 S06E42 0120 DAO 9810 2002.02.01 2 N09E68 0200 CSO 9811 2002.02.02 1 S27E83 0090 HAX 9812 2002.02.02 2 N12W16 0010 DSO Total number of sunspots: 122 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 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 107.6 (+2.8) 2001.05 147.1 96.6 108.7 (+1.1) 2001.06 173.0 134.0 109.8 (+1.1) 2001.07 131.3 82.2 111.7 (+1.9) 2001.08 162.9 106.8 (113.5 predicted, +1.8) 2001.09 233.2 150.7 (113.3 predicted, -0.2) 2001.10 207.6 125.6 (111.0 predicted, -2.3) 2001.11 210.6 106.5 (109.6 predicted, -1.4) 2001.12 235.1 131.8 (106.2 predicted, -3.4) 2002.01 226.6 113.9 (102.6 predicted, -3.6) 2002.02 243.3 (1) 17.1 (2) (101.2 predicted, -1.4) 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. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News]