Solar Terrestrial Activity Report [Image] Last update July 3, 2002 at 04:10 UTC. Minor update posted at 08:49 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update July 1, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update July 1, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update July 1, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was quiet to unsettled on July 2. Solar wind speed ranged between 377 and 456 km/sec. Solar flare activity was moderate. Solar flux was 148.5 (probably slightly enhanced by a C5 flare in region 10017 as the measurements at 17 and 23h UTC were at the 144 level), the planetary A index was 9 (3-hour K indices: 3321 2233, Boulder K indices: 2121 2122). Region 10011 developed slowly and quietly, the region will be rotating over the southwest limb today. Region 10016 was quiet and stable. Region 10017 was very interesting to observe all day. The penumbra in the southwest drifted away from the dominant penumbra in the northeast of the region and decayed. Instead incredibly quick development occurred due south of the northernmost penumbra. By noon the developing (magnetically negative) penumbra in the south had begun to join with the northern (magnetically positive) penumbra thereby creating a magnetic delta. By late afternoon the delta had become strong and by midnight region 10017 was larger than region 10019. Further X class flares are possible as long as the current delta configuration persists. Region 10019 developed slowly with the large northern penumbra extending longitudinally. The most interesting development occurred in and near the westernmost penumbra where polarities currently are thoroughly intermixed. That section of region 10019 should probably be split into a separate region as neither the positive or negative magnetic areas are connected to that of the main part of the large region. M class flares are possible, even a major flare could occur in region 10019. Region 10020 rotated into view at the east limb. The southernmost spot is in the southern hemisphere while the two other spots are in the northern hemisphere. Two other small, spotted regions rotating into view at the southeast limb were not noticed by SEC/NOAA. Comment added at 08:49 UTC on July 3: The X1 flare early today does not appear to have been associated with a significant CME. Flares and CMEs A total of 7 C and 1 M class events was recorded on July 2. Region 10019 produced a C2.3 flare at 14:17 and a C1.0 flare at 18:36 UTC. Region 10017 generated a C5.2 flare at 20:01 and an M1.5 flare at 20:31 UTC. At 02:13 UTC on July 3 region 10017 produced an impulsive X1.5 flare. No LASCO C2 images after this event have become available as I write this, and it is therefore difficult to tell if there was a geoeffective CME associated with the major flare. When images become available I will issue an update, until then have a look at this image from the Learmonth observatory taken at the exact peak of the flare. A large filament in the northern hemisphere near the equator and rotating across the central meridian is currently quiet. An eruption in this filament will likely be associated with a large CME. The background x-ray flux is at the class B5 level. Coronal holes A trans equatorial coronal hole will rotate into a geoeffective position on July 3 and could cause a geomagnetic disturbance on July 6. This coronal hole has developed slowly and appears to be connected to the northern polar coronal hole. Forecast The geomagnetic field is expected to be quiet to unsettled on July 3. The forecast for July 4 and 5 is uncertain due to the X1 flare early on July 3. 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 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 10011 2002.06.22 5 S12W77 0050 DSO 10014 2002.06.23 S18W67 plage 10015 2002.06.24 S26W68 plage 10016 2002.06.25 1 S15W22 0040 HSX 10017 2002.06.27 15 S18W51 0400 DKI beta-gamma-delta 10019 2002.06.29 11 S18E34 0510 DKI beta-gamma 10020 2002.07.02 3 N01E63 0010 BXO Total number of sunspots: 35 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 2001.06 173.0 134.0 109.8 (+1.2) 2001.07 131.3 81.8 111.7 (+1.9) 2001.08 162.9 106.4 113.6 (+1.8) 2001.09 233.2 150.7 114.1 (+0.5) 2001.10 207.6 125.5 114.0 (-0.1) 2001.11 210.6 106.5 115.5 (+1.5) 2001.12 235.1 132.2 114.6 (-0.9) 2002.01 226.6 114.1 (112.7 predicted, -1.9) 2002.02 205.0 107.4 (111.3 predicted, -1.4) 2002.03 179.5 98.4 (106.6 predicted, -4.7) 2002.04 189.8 120.4 (100.7 predicted, -5.9) 2002.05 178.4 120.8 (96.3 predicted, -4.4) 2002.06 148.7 88.5 (91.7 predicted, -4.6) 2002.07 148.0 (1) 5.5 (2) (86.9 predicted, -4.8) 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]