Solar Terrestrial Activity ReportSolar Terrestrial Activity Report

Last update March 11, 2002 at 04:10 UTC. 
[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 4, 2002)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 4, 2002)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 4, 
2002)]
[Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 
2002)]
Recent development
The geomagnetic field was quiet to slightly active on March 10. Solar wind speed 
ranged between 353 and 427 km/sec.
Solar flare activity was moderate. Solar flux was 179.3, the planetary A index 
was 9 (3-hour K indices: 1104 4223, Boulder K indices: 1103 3222). Region 9851 
decayed further and has only a small penumbra left. Region 9853 decayed into 
spotless plage. Region 9856 was quiet and stable. Region 9859 decayed further 
and could become spotless today. Region 9864 decayed slowly and was mostly 
quiet. Region 9865 was quiet and stable. Region 9866 developed slowly and has a 
weak magnetic delta structure in the trailing spots section. A major flare is 
possible. A spotted region rotated into view at the southeast limb fairly early 
in the day but somehow escaped being noticed by SEC/NOAA.
Flares and CMEs
A total of 8 C and 1 M class events were recorded on March 10. Region 9866 
produced a C6.0 flare at 05:05 and a C2.6 flare at 21:55 UTC. The remainder of 
the flares were optically uncorrelated. A long duration M2.3 event peaked at 
23:25 UTC and had its source at the southeast limb. A large eastward directed 
CME was observed in LASCO images following this event.
The background x-ray flux is at the class C1 level.
Coronal holes
No obvious coronal holes are currently approaching geoeffective positions.
Forecast
The geomagnetic field is expected to be quiet to unsettled on March 11-13. Long 
distance medium wave (AM) band propagation along east-west paths over high and 
upper middle latitudes is fair to poor.
      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
      98512002.03.014S06W670060DAOarea too large,
      should be 0020.
      classification wrong
      98522002.03.01 N17W57  plage
      98532002.03.022S24W390020CROnow spotless
      98552002.03.03 N13W68  plage 
      98562002.03.035S03W180150CSO 
      98582002.03.04 S29W73  plage
      98592002.03.047S11W330030CRO 
      98602002.03.05 S06W04  plage
      98612002.03.05 N08E01  plage
      98632002.03.06 N18W89  plage
      98642002.03.076N20E290090CAO 
      98652002.03.081N15E430020HRX 
      98662002.03.0819S09E610840EKIbeta-gamma-delta
      Total number of sunspots:44 

Monthly solar data
      MonthAverage solar fluxInternational sunspot numberSmoothed sunspot number
      2000.04184.2125.5120.8
      cycle 23 sunspot max. 
      2000.07202.3170.1119.8
      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)
      2001.08162.9106.8113.6 (+1.8)
      2001.09233.2 150.7(113.7 predicted, +0.1)
      2001.10207.6125.6(111.7 predicted, -2.0)
      2001.11210.6106.5(110.2 predicted, -1.5)
      2001.12235.1131.8(106.9 predicted, -3.3)
      2002.01226.6113.9(103.3 predicted, -3.6)
      2002.02205.0108.0(101.9 predicted, -1.4)
      2002.03180.6 (1) 49.6 (2)(97.6 predicted, -4.3)

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 25-45% 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.


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