Solar Terrestrial Activity Report [Image] Last update March 27, 2002 at 05:05 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 unsettled on March 26. Solar wind speed ranged between 362 and 585 km/sec. A fairly benign coronal stream was in progress most of the day and caused only a small increase in geomagnetic activity. Solar flare activity was low. Solar flux was 165.7 (this is the lowest solar flux level since August 22, 2001), the planetary A index was 11 (3-hour K indices: 3213 3323, Boulder K indices: 223 3323). Region 9875 decayed slowly and quietly. Region 9876 decayed slowly and quietly. Region 9878 developed slowly and could produce minor M class flares. Region 9880 decayed early in the day, some new development was observed during the latter half of the day. Region 9881 decayed losing several spots and most of the penumbral area in the leader spots. Region 9882 decayed into spotless plage, while a new and unimpressive region emerged just west of the region. This development was apparently not noticed by SEC/NOAA. Region 9883 was quiet and stable. Flares and CMEs A total of 6 C class events were recorded on March 26. Region 9878 produced a C3.0 flare at 15:21 UTC. Region 9881 generated a C2.1 flare at 20:02 and a C1.5 flare at 20:30 UTC. The background x-ray flux is at the class B5 level. Coronal holes A large recurrent trans equatorial coronal hole will rotate into a geoeffective position on March 28-30. Forecast The geomagnetic field is expected to be quiet to unsettled on March 27-30. A coronal stream will likely reach the Earth on March 31 and cause unsettled to active conditions, perhaps with a few isolated minor storm intervals. 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 no. Location at region numbered sunspots midnight Area Classification Comment 9874 2002.03.19 N18W69 plage 9875 2002.03.19 2 S21W36 0060 DAO 9876 2002.03.20 23 S15W08 0140 EAI 9878 2002.03.20 23 N08E00 0170 ESI beta-gamma 9880 2002.03.21 11 N08W36 0080 DAO 9881 2002.03.22 11 S03W62 0180 DSO 9882 2002.03.22 4 N16E14 0020 DSO 9883 2002.03.23 1 N06E30 0040 HSX Total number of sunspots: 75 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 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) 2001.08 162.9 106.8 113.6 (+1.8) 2001.09 233.2 150.7 (113.7 predicted, +0.1) 2001.10 207.6 125.6 (111.7 predicted, -2.0) 2001.11 210.6 106.5 (110.2 predicted, -1.5) 2001.12 235.1 131.8 (106.9 predicted, -3.3) 2002.01 226.6 113.9 (103.3 predicted, -3.6) 2002.02 205.0 108.0 (101.9 predicted, -1.4) 2002.03 178.6 (1) 126.4 (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. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News]