Solar Terrestrial Activity Report [Image] Last update June 19, 2001 at 01:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update June 3, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update June 4, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update June 4, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update April 8, 2001)] Recent development The geomagnetic field was mostly active to minor storm on June 18 with a single quiet interval at the beginning of the day and brief major storm conditions during the 09-12h UTC interval. Solar wind speed ranged between 276 and 430 km/sec. A dense solar wind shock was observed at SOHO at 01:53 UTC. Solar wind speed increased abruptly from 290 to 340 km/sec. Solar flare activity was moderate. Solar flux was 199.2 (the reading at 17h UTC was used because both the 20h and 23h UTC readings where flare enhanced), the planetary A index was 34 (3-hour K indices: 2556 5344, Boulder K indices: 3555 4434). Regions 9491 and 9493 rotated quietly off the visible disk. Region 9498 decayed slowly and could become spotless today or tomorrow. Region 9499 decayed and rotated off the visible disk early today. Region 9500 decayed slowly and was mostly quiet. Region 9501 was mostly unchanged and quiet. Region 9502 decayed significantly and could soon become spotless if the current rate of decay continues. Region 9503 was generally unchanged and still has major flare potential. Region 9504 was quiet and stable. An M class flare is possible. Region 9506 did not change much and could produce further minor M class flares. Flares and CMEs A total of 6 C and 1 M class events were recorded on June 18. Region 9506 produced a C1.6 long duration event peaking at 02:30, a C2.3 long duration event peaking at 13:04 and an M2.0/2N long duration event peaking at 20:21 UTC. The region may have been the source of another long duration event which peaked at 23:00 UTC at the C4.5 level as well. Region 9500 generated a C2.8/1F flare at 06:19 UTC. Region 9503 was the source of a C4.2 flare at 14:55 UTC. The background x-ray flux is at the class B8 level. Coronal holes A small well placed coronal hole was in a geoeffective position on June 16. The associated coronal stream could influence the geomagnetic field on June 19. Forecast The geomagnetic field is expected to be quiet to minor storm on June 19 and quiet to unsettled on June 20-21. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to very 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 9491 2001.06.05 2 N27W91 0070 HAX 9493 2001.06.06 1 N07W89 0060 HSX 9497 2001.06.10 S09W80 plage 9498 2001.06.10 1 N23W50 0020 HRX 9499 2001.06.11 1 N20W83 0030 HSX 9500 2001.06.11 5 N11W22 0040 CAO 9501 2001.06.11 10 S14W24 0080 CAO 9502 2001.06.12 10 S26W08 0060 DAO 9503 2001.06.13 42 N14E07 0470 EKI beta-gamma 9504 2001.06.13 5 N08E11 0320 CKO 9505 2001.06.14 3 N21E19 0060 DAO 9506 2001.06.14 30 N17E34 0330 FAI beta-gamma 9507 2001.06.15 N12W14 plage 9508 2001.06.16 S20W85 plage Total number of sunspots: 110 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 (+3.1) 2000.04 184.2 125.5 120.8 (+0.9) cycle 23 sunspot max. 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 170.1 119.7 (+1.0) 2000.08 163.0 130.5 118.6 (-1.1) 2000.09 182.1 109.7 116.2 (-2.4) 2000.10 167.4 99.4 114.5 (-1.7) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 (111.1 predicted, -1.7) 2001.01 166.6 95.6 (107.6 predicted, -3.5) 2001.02 146.6 80.6 (102.8 predicted, -4.8) 2001.03 177.7 113.5 (99.2 predicted, -3.6) 2001.04 177.7 108.2 (98.0 predicted, -1.2) 2001.05 147.1 97.3 (97.3 predicted, -0.7) 2001.06 170.9 (1) 121.8 (2) (94.6 predicted, -2.7) 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. ------------------------------------------------------------------------ Do you know about the survey which will be held this Summer among the listeners of WWV and WWVH? There is information about this survey at 16 minutes past the hour on WWV and at 47 minutes past the hour on WWVH. If you want to participate send an email with your name and address. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]