Solar Terrestrial Activity ReportSolar Terrestrial Activity Report

Last update February 22, 2002 at 05:35 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 unsettled on February 21. Solar wind speed 
ranged between 374 and 480 km/sec.
Solar flare activity was moderate. Solar flux was 201.1, the planetary A index 
was 6 (3-hour K indices: 1121 2233, Boulder K indices: 1122 3233). Region 9824 
rotated quietly off the visible disk. Region 9825 rotated fully off the 
northwest limb early in the day. Region 9830 decayed significantly and lost 
quite a bit of its penumbral coverage. A strong magnetic delta is still there 
and the region remains capable of producing a major flare. Region 9832 was quiet 
and stable. Region 9834 reemerged with a single spot. Region 9835 developed 
early in the day, then was mostly unchanged for the remainder of the day. C 
class flares are possible. Region 9837 was quiet and stable. New region 9839 
emerged briefly in the southeast quadrant, no spots are visible early on Feb.22. 
New region 9840 rotated into view at the southeast limb.
Flares and CMEs
A total of 6 C and 4 M class events were recorded on February 21. Region 9825 
produced a C3.6 flare at 04:48. a C7.0 flare at 09:32, an M1.0 flare at 18:23 
and an M1.4 flare at 20:37 UTC. Region 9830 generated a C3.5 flare at 16:48 and 
an M4.4/2N flare which began at 23:49 UTC and peaked at 00:10 UTC on February 
22. 
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 February 22-23. 
Long distance medium wave (AM) band propagation along east-west paths over high 
and upper middle latitudes is fair.
      Coronal holes (1)Coronal mass ejections (2)M and X class flares (3)


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 regionDate numberedActual no. sunspotsLocation at 
      midnightAreaClassificationComment
      98242002.02.091N24W860080HSX
      98252002.02.092N13W920120CAObeta-gamma
      98282002.02.11 S14W84plage
      98292002.02.14 S06W14  plage
      98302002.02.1429S19W220530FKIbeta-gamma-delta 
      98322002.02.182S15W160010HSX 
      98332002.02.19 N11W42  plage
      98342002.02.191N03E270010HSX
      98352002.02.203S09W750170DAO 
      98362002.02.20 S02W39  plage
      98372002.02.201N08E570140HAX 
      98382002.02.214N05W180020CRO 
      98392002.02.213S16E060010BXOnow spotless 
      98402002.02.212S12E720020AXX 
      Total number of sunspots:48 

Monthly solar data
      MonthAverage solar fluxInternational sunspot numberSmoothed sunspot number
      2000.04184.2125.5120.8
      cycle 23 sunspot max. 
      2000.07202.3170.1119.8
      2000.12173.6104.4112.0 (-0.7)
      2001.01166.695.6108.7 (-3.3)
      2001.02146.680.6104.1 (-4.6)
      2001.03177.7113.5104.8 (+0.7)
      2001.04177.7107.7107.6 (+2.8)
      2001.05147.196.6108.7 (+1.1)
      2001.06173.0134.0109.8 (+1.1)
      2001.07131.382.2111.7 (+1.9)
      2001.08162.9106.8(113.5 predicted, +1.8)
      2001.09233.2 150.7(113.3 predicted, -0.2)
      2001.10207.6125.6(111.0 predicted, -2.3)
      2001.11210.6106.5(109.6 predicted, -1.4)
      2001.12235.1131.8(106.2 predicted, -3.4)
      2002.01226.6113.9(102.6 predicted, -3.6)
      2002.02207.0 (1)145.6 (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]