Solar Terrestrial Activity Report [Image] Last update December 29, 2001 at 05:00 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update December 2, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update October 16, 2001)] Recent development The geomagnetic field was quiet to unsettled on December 28. Solar wind speed ranged between 338 and 407 km/sec. The partial halo CME observed on December 26 was observed at ACE at 04:50 UTC on Dec.29. Solar wind speed increased abruptly from 370 to 480 km/sec. The interplanetary magnetic field has initially been northwards. Solar flare activity was high. Solar flux was 263.3 (this is the solar flux measured at 18h UTC, the values at 20 and 22h UTC were exceptionally high because of an intense long duration event), the planetary A index was 5 (3-hour K indices: 1012 2222, Boulder K indices: 1022 3333). Region 9742 rotated over the northwest limb. Region 9743 was spotless all day, but not so according to SEC/NOAA. Region 9748 is rotating over the southwest limb and may be capable of producing minor M class flares. Region 9751 was generally unchanged and is capable of M class flaring. Region 9753 was quiet and stable. Region 9754 developed and appears to have a magnetic delta structure. M class flares are possible. Region 9755 was quiet and stable, as was region 9756. Region 9757 was quiet and stable. Region 9760 decayed into spotless plage. Region 9761 was quiet and stable. Region 9762 decayed and was spotless by midnight. Region 9763 was quiet and stable. New region 9764 emerged in the northeast quadrant. New region 9765 rotated into view at the northeast limb. A very interesting region is about to rotate into view at the southeast limb. This region produced an impressive full halo CME a few days ago and was the source of a very long duration X3 event on Dec.28. Flares and CMEs A total of 3 C, 3 M and 1 X class events were recorded on December 28. Region 9754 produced a C4.2 flare at 02:40 and an M1.0/1F flare at 06:55 UTC. Region 9742 generated an impulsive M4.7 flare at 03:51 UTC. Region 9748 was the source of an M1.3 long duration event peaking at 12:30 UTC, while region 9751 managed a C8.2/1F flare at 18:53 UTC. A region at the southeast limb produced a very long duration major X3.4 event peaking at 20:45 UTC. (See SOHO EIT images just after the peak and with a well defined loop system early on December 29.) A very large and very fast (speed above 2000 km/sec) full halo CME was observed beginning at 20:06 UTC in LASCO C2 images. Although Earth fortunately will not receive the main shock from this CME, there is a possibility of a minor shock on December 30 or 31. The background x-ray flux is at the class C3 (actually M1 early on December 29) level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active, possibly minor storm on December 29 and quiet to unsettled on December 30-31. 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 9742 2001.12.15 7 N12W94 0350 EKI beta-gamma-delta 9743 2001.12.16 1 S10W89 0060 HSX actually spotless 9745 2001.12.18 N18W75 plage 9747 2001.12.19 N12W52 plage 9748 2001.12.20 12 S11W77 0250 EAO 9749 2001.12.20 S08W35 plage 9751 2001.12.21 34 N04W24 0380 EAI beta-gamma 9753 2001.12.22 13 S19W19 0060 ESO 9754 2001.12.23 28 S08W02 0200 FAI beta-gamma-delta? 9755 2001.12.25 6 S04E23 0170 CSO 9756 2001.12.26 5 S29E47 0120 CAO 9757 2001.12.26 3 S10W26 0010 BXO 9758 2001.12.26 N13W06 plage 9759 2001.12.26 N17E02 plage 9760 2001.12.26 N07E08 plage 9761 2001.12.26 1 N10E47 0070 HSX 9762 2001.12.27 1 N02W07 0000 AXX now spotless 9763 2001.12.27 4 N06E61 0080 CSO 9764 2001.12.28 5 N12E15 0010 BXO 9765 2001.12.28 3 N05E78 0070 DSO Total number of sunspots: 123 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 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.7 (-1.8) 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 (109.3 predicted, +0.6) 2001.07 131.3 82.2 (109.8 predicted, +0.5) 2001.08 162.9 106.8 (110.3 predicted, +0.5) 2001.09 233.2 150.7 (109.7 predicted, -0.6) 2001.10 207.6 125.6 (107.0 predicted, -2.7) 2001.11 210.6 106.5 (105.3 predicted, -1.7) 2001.12 233.3 (1) 196.6 (2) (102.0 predicted, -3.3) 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]