Solar Terrestrial Activity Report [Image] Last update March 1, 2002 at 05:20 UTC. The next update will be on Sunday March 3 as I will be away most of the weekend. [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 28. Solar wind speed ranged between 317 and 449 km/sec. An unexpected solar wind shock was observed at 03:49 UTC at SOHO. Solar wind speed increased abruptly from 340 to 380 km/sec. The source of this CME is not clear. While the disturbance was fairly mild most of the day, the interplanetary magnetic field had a sustained period of moderate to strong southward swing beginning after 17h UTC and ending near midnight. Solar flare activity was low. Solar flux was 204.2, the planetary A index was 17 (3-hour K indices: 1343 3335, Boulder K indices: 1333 3334). Region 9837 had been spotless since the evening on February 27 but was somehow observed by SEC/NOAA as having two spots. Region 9839 rotated quietly off the visible disk. Region 9842 decayed slowly and will be rotating over the southwest limb early on March 2. Region 9843 was mostly quiet and unchanged. Region 9844 developed slowly and could produce minor M class flares. Region 9845 developed slowly and could produce minor M class flares. Region 9846 rotated quietly off the visible disk . Region 9847 decayed into spotless plage. Region 9848 decayed quite a bit and could soon become spotless. Region 9850 decayed and could soon become spotless. A new region is developing near the southeast limb. Flares and CMEs A total of 5 C class events were recorded on February 28. Region 9848 produced a C4.0 flare at 09:27 UTC. Region 9844 generated a C7.6 flare at 19:10 UTC. The background x-ray flux is at the class C1 level. Coronal holes A recurrent trans equatorial coronal hole will rotate into a geoeffective position on March 1 and is likely to cause unsettled to minor storm conditions on March 4-5. Forecast The geomagnetic field is expected to be quiet to active on March 1 and quiet to unsettled on March 2-3. 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 9834 2002.02.19 N03W65 plage 9837 2002.02.20 2 N10W31 0010 AXX actually spotless! 9839 2002.02.21 5 S18W84 0100 DAO 9840 2002.02.21 S11W19 plage 9842 2002.02.22 4 S18W73 0130 DAO 9843 2002.02.22 12 S26W20 0060 DSO 9844 2002.02.23 24 N22W34 0230 DAI 9845 2002.02.23 25 N18E08 0320 EAI 9846 2002.02.24 3 S05W91 0030 DAO 9847 2002.02.24 2 S13W01 0010 AXX 9848 2002.02.25 8 S20W07 0050 DSO 9849 2002.02.25 N23E29 plage 9850 2002.02.27 3 N27W64 0030 CRO Total number of sunspots: 88 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) 2002.02 205.0 (1) 194.5 (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]