Solar Terrestrial Activity Report [Image] Last update July 16, 2002 at 04:00 UTC. Please note that the next major update probably will be on August 3 as I will be on vacation until then. [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 active on July 15. Solar wind speed ranged between 290 and 339 km/sec. A small solar wind shock was observed at SOHO at approximately 16:45 UTC. This caused an increase in geomagnetic activity during the first few hours after the disturbance reached Earth and again during the early hours of July 16. Solar flare activity was high. Solar flux was 159.5 (the measurement at 17h UTC was used as the readings at 20 and 23h UTC were enhanced by flare activity), the planetary A index was 8 (3-hour planetary K indices: 2211 2342, Boulder K indices: 2211 1222). Region 10025 decayed further and had only a tiny spot left at the end of the day. Region 10028 developed slowly adding a few small spots. Region 10029 decayed further and was spotless by the end of the day. Region 10030 continued to develop quickly in the intermediate and trailing spot sections adding a large amount of penumbral area. Some decay was observed, particularly in the leading spot section where many small spots had disappeared by midnight and between the intermediate and trailing spot section where several spots disappeared. Several small magnetic deltas can be observed in the central spots section. Another major flare and a geoeffective CME is possible anytime over the next few days, the next major flare could even be a proton flare. Region 10031 was spotless all day in all available images, additionally no spots were observed by Mt.Wilson. Region 10033 was quiet and stable. Region 10034 decayed and appears to be spotless early on July 16. New region 10035 rotated into view at the southeast limb early in the day. Around noon two new regions rotated into view at the southeast limb. SEC/NOAA grouped both regions into one (probably because of little separation between the regions) naming it region 10036. In magnetograms the southern and northern spot groups are currently two separate regions. The southern spot group could have a small magnetic delta structure. Flares and CMEs A total of 8 C, 1 M and 1 X class events was recorded on July 15. Region 10030 produced a C1.6 flare at 02:02, a C1.6 flare at 04:23, a C3.8 flare at 05:12, a C1.6 flare at 10:29, a C9.1 flare at 11:55, a C3.6 flare at 14:04, a C1.9 flare at 18:40, a major X3.0/3B at 20:08 and a long duration M1.8 event peaking at 21:32 UTC. A strong type IV sweep was recorded along with the two latter events. A full halo CME was observed in LASCO images with ejected material first observed over the northeast limb at 20:30 UTC in C2 images. The main core of the fast CME also headed northeastwards. While Earth will receive an impact from this CME, probably during the latter half of July 17, it appears as if the main part of the solar storm will not be geoeffective. Still, minor to major geomagnetic storming is expected. It should be noted that a coronal stream is likely to reach Earth prior to the arrival of the CME, and this could diminish the effects of the CME. The background x-ray flux is at the class B8 level. Coronal holes A coronal hole in the southern hemisphere was in a geoeffective position on July 14 and could cause a minor geomagnetic disturbance on July 17. Another coronal hole in the southern hemisphere will rotate into a geoeffective position on July 16 and 17 and could cause a minor geomagnetic disturbance on July 19-20. Forecast The geomagnetic field is expected to be quiet to active on July 16 and unsettled to major storm on July 17-18. 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 10025 2002.07.04 1 S19W71 0020 HSX area only 0010 at midnight 10027 2002.07.07 S15W78 plage 10028 2002.07.08 5 S16W59 0020 BXO 10029 2002.07.08 3 S13W48 0020 HRX now spotless beta-gamma-delta 10030 2002.07.09 90 N18E00 0930 FKC area too small, should be above 1200. 10031 2002.07.11 3 N09E11 0010 AXX actually spotless 10032 2002.07.13 S20W40 plage 10033 2002.07.13 4 N08W26 0020 CSO 10034 2002.07.14 7 S20W09 0010 CRO spotless early on July 16 10035 2002.07.15 2 S09E63 0020 BXO actually two separate 10036 2002.07.15 4 S07E76 0090 DAO regions, one may have a beta-delta structure Total number of sunspots: 119 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) 2002.07 140.0 (1) 62.9 (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]