Solar Terrestrial Activity Report [Image] Last update June 4, 2001 at 03:45 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 quiet to active on June 3. Solar wind speed ranged between 440 and 563 km/sec under the influence of a coronal stream. Solar flare activity was low. Solar flux was 145.3, the planetary A index was 11 (3-hour K indices: 2232 3433, Boulder K indices: 2232 3432). Region 9474 decayed and was spotless by the end of the day. Region 9475 did not change significantly and was quiet. Region 9477 decayed into spotless plage. Region 9482 was quiet and stable. Region 9483 was quiet and rotated off the visible disk early on June 4. Region 9484 developed slowly and could produce C flares. Region 9485 was quiet and stable. Region 9486 developed slowly and is a reversed polarity region. Region 9487 was quiet and stable and may be capable of producing occasional minor M class flares. New region 9488 was split off from region 9485. The region has a magnetic delta configuration and could produce minor M class flares. Flares and CMEs A total of 5 C class events were recorded on June 3. Region 9488 produced a C1.1 flare at 06:59 and a C5.6/1F flare at 21:22 UTC. Region 9484 was the source of a C1.0 flare at 19:05 and a C2.4 flare at 20:11 UTC. The background x-ray flux is at the class B5 level. Coronal holes A coronal hole in the northern hemisphere has a long, fingerlike extension which rotated into a geoeffective position on June 2. The main part of the coronal hole should rotate into a geoeffective position on June 5-6. Forecast The geomagnetic field is expected to be quiet to active on June 4. Late on June 5 another coronal stream could start, causing the geomagnetic field to range between quiet and active. 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 region numbered sunspots at Area Classification Comment midnight 9472 2001.05.23 N14W83 plage 9474 2001.05.26 1 N22W51 0010 AXX now spotless 9475 2001.05.26 9 N19W29 0070 DAO 9477 2001.05.27 S17W68 plage 9478 2001.05.27 N13W77 plage 9480 2001.05.28 S13W29 plage 9482 2001.05.30 1 S16W04 0010 AXX 9483 2001.06.01 2 S22W84 0020 BXO 9484 2001.06.01 20 S06E08 0110 DAI beta-gamma 9485 2001.06.01 1 S23E46 0030 HRX 9486 2001.06.02 9 N28W22 0070 DAO 9487 2001.06.02 4 N19E60 0340 CKO 9488 2001.06.03 6 S18E61 0280 CKO beta-delta Total number of sunspots: 53 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 (110.5 predicted, -2.3) 2001.01 166.6 95.6 (106.8 predicted, -3.7) 2001.02 146.6 80.6 (102.4 predicted, -4.4) 2001.03 177.7 113.5 (98.8 predicted, -3.6) 2001.04 177.7 108.2 (97.6 predicted, -1.2) 2001.05 147.1 97.3 (96.9 predicted, -0.7) 2001.06 137.4 (1) 13.7 (2) (94.2 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]