Solar Terrestrial Activity ReportSolar Terrestrial Activity Report Last update June 2, 2002 at 04:00 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 2, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update June 2, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update June 2, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was quiet to unsettled on June 1. Solar wind speed ranged between 304 and 353 km/sec. A minor disturbance was observed beginning at approximately 15:30 UTC at ACE. Solar wind speed has since then increased slowly and is as I write this near 420 km/sec. The source of this disturbance is a weak coronal stream. Solar flare activity was moderate. Solar flux was 178.8, the planetary A index was 8 (3-hour K indices: 1022 2333, Boulder K indices: 1021 1322). Region 9963 decayed slowly as it began to rotate out of view at the northwest limb. Region 9965 decayed and was spotless by the end of the day. Region 9970 decayed slowly and quietly. Region 9972 decayed further. If the region continues to decay at the current rate it will become spotless within a day or two. Region 9973 developed slowly and remains capable of producing M class flares, perhaps even a major flare. Region 9974 was quiet and stable. Region 9975 decayed and was spotless by late afternoon. Region 9976 decayed and was spotless by the end of the day. Region 9977 developed slowly and quietly. Region 9978 was quiet and stable during the first half of the day, then began to develop quickly and at midnight had a larger penumbral coverage than neighboring region 9979. Region 9979 developed slowly and could produce further minor M class flares. The region has a magnetic delta structure at its center. New region 9980 emerged in the southeast quadrant. Flares and CMEs A total of 12 C and 2 M class events were recorded on June 1. Region 9973 produced an impulsive M1.5/1N flare at 03:57 UTC. This event was accompanied by moderately strong type II and IV radio sweeps. As no new LASCO C2 or C3 images have become available since very early on June 1, it is difficult to tell if the CME produced by the flare is geoeffective. LASCO EIT images indicate a fairly narrow CME heading southeastwards (no EIT wave or dimming was observed), but it is possible that some parts of the CME could reach Earth on June 4. Another event with its origin in region 9973 was an impulsive C5.1 flare at 23:49 UTC. A weak type II and a moderate type IV sweep were recorded and it is likely that a geoeffective CME was associated with this event. In that case the CME is likely to reach Earth on June 4. Region 9979 generated a C4,.8 flare at 06:41 and an impulsive M1.1 flare at 10:49 UTC. Region 9977 was the source of a C1.5 flare at 08:43 UTC. Several small C flares and some long duration events were not optically correlated, this includes C2 long duration events peaking at approximately 15:40, 21:40 and 23:11 UTC. The background x-ray flux is at the class B8 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on June 2, quiet to unsettled on June 3 and quiet to active or minor storm on June 4-5. 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 ejections (2)M and X class flares (3) 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 regionDate numberedActual no. sunspotsLocation at midnightAreaClassificationComment 99632002.05.201N17W840220HAX 99652002.05.221S07W750030HSXnow spotless 99662002.05.23 N10W88 plage 99672002.05.23 N12W78 plage 99682002.05.24 S14W78 plage 99692002.05.25 N09W22 plage 99702002.05.265N05W260090DSO 99712002.05.28 N21W52 plage 99722002.05.2810S21E040070DSO 99732002.05.2830S17E230790EKIbeta-gamma 99742002.05.291N19E190020HSX 99752002.05.292N22E190010BXOnow spotless 99762002.05.303S10W270010BXOnow spotless 99772002.05.317S20W540050CSO 99782002.05.313S20E470040CSOarea way too small, spot number too low 99792002.05.317S30E630130DAObeta-gamma-delta 99802002.06.012S29E080000AXX Total number of sunspots:72 Monthly solar data MonthAverage solar fluxInternational sunspot numberSmoothed sunspot number 2000.04184.2125.5120.8 cycle 23 sunspot max. 2000.07202.3170.1119.8 2001.05147.196.6108.6 (+1.1) 2001.06173.0134.0109.8 (+1.2) 2001.07131.382.2111.7 (+1.9) 2001.08162.9106.8113.6 (+1.8) 2001.09233.2 150.7114.1 (+0.5) 2001.10207.6125.5114.0 (-0.1) 2001.11210.6106.5115.5 (+1.5) 2001.12235.1132.2(115.1 predicted, -0.4) 2002.01226.6113.9(113.8 predicted, -1.3) 2002.02205.0108.0(112.9 predicted, -0.9) 2002.03179.598.1(108.4 predicted, -4.5) 2002.04189.8120.4(102.5 predicted, -5.9) 2002.05178.4120.8(98.1 predicted, -4.4) 2002.06178.8 (1)6.4 (2)(93.5 predicted, -4.6) 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]