Solar Terrestrial Activity Report [Image] Last update May 16, 2002 at 04:35 UTC. Minor update posted at 06:10 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update May 3, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update May 3, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update May 3, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was quiet to active on May 15. Solar wind speed ranged between 358 and 466 km/sec. Solar flare activity was moderate. Solar flux was 159.2, the planetary A index was 16 (3-hour K indices: 4434 3322, Boulder K indices: 4323 2222). Region 9937 was spotless all day in all available images, SEC/NOAA somehow managed to observe two spots. Region 9945 decayed significantly losing most of the penumbral area in the trailing spots. An M class flare is still possible. Region 9948 was mostly unchanged and remains capable of producing occasional M class flares. Region 9949 was spotless all day in all available images, yet again SEC/NOAA observed a single small spot. Region 9950 was generally unchanged and quiet. Region 9951 decayed and could become spotless later today. New region 9953 emerged in the northwest quadrant. New region 9964 near the southeast limb was finally numbered. The region is developing and may be capable of minor M class flaring. New region 9955 rotated into view at the southeast limb. SEC/NOAA incredibly failed to number a region which rotated into view at the northeast limb fairly early in the day. Early on May 16 a much larger region is rotating into view at the northeast limb. Activity observed in SOHO/LASCO images over the last days indicate that the region flares often and probably has M class flaring potential. Comment added at 06:10 UTC on May 16: Region 9948 was the source of a long duration C4 event early today. LASCO C3 images indicate that a full halo CME was associated with this event. The CME will likely impact the Earth during the latter half of May 18 and could cause unsettled to minor storm conditions. The region at the northeast limb appears to have been the source of a C5 flare at 05:20 UTC. Flares and CMEs A total of 3 C and 1 M class events were recorded on May 15. Region 9948 produced an M1.0 flare at 08:13 UTC. No distinct CME was observed in LASCO images following this event. A long duration C2 event began after 09h UTC and was caused by a large filament eruption in the northwest quadrant. The CME produced by this event was likely not geoeffective. A long duration C4 event early on May 16 has produced at least a partial halo CME covering the southern hemisphere and parts of the northern hemisphere. More details will follow on this event as new images become available. The background x-ray flux is at the class B7 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on May 16-17. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9937 2002.05.03 2 S08W89 0030 AXX actually spotless 9938 2002.05.03 S06W86 plage 9940 2002.05.04 N19W80 plage 9943 2002.05.05 S10W68 plage 9944 2002.05.07 N08W69 plage 9945 2002.05.07 18 S05W39 0280 DAO beta-gamma 9946 2002.05.08 S06W30 plage 9948 2002.05.10 7 S22E14 0420 EKO 9949 2002.05.11 1 S16W61 0000 AXX actually spotless 9950 2002.05.11 11 S06W09 0050 CSO 9951 2002.05.12 1 N11E28 0010 HSX 9952 2002.05.13 S15W48 plage 9953 2002.05.15 3 N06W52 0010 DRO 9954 2002.05.15 3 S22E65 0150 CAO 9955 2002.05.15 1 S14E67 0040 HSX Total number of sunspots: 47 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 2001.04 177.7 107.7 107.5 (+2.7) 2001.05 147.1 96.6 108.6 (+1.1) 2001.06 173.0 134.0 109.8 (+1.2) 2001.07 131.3 82.2 111.7 (+1.9) 2001.08 162.9 106.8 113.6 (+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 (114.7 predicted, +0.7) 2001.12 235.1 132.2 (112.5 predicted, -2.2) 2002.01 226.6 113.9 (109.8 predicted, -2.7) 2002.02 205.0 108.0 (108.4 predicted, -1.4) 2002.03 179.5 98.1 (104.2 predicted, -4.2) 2002.04 189.8 120.4 (98.3 predicted, -3.9) 2002.05 179.2 (1) 104.5 (2) (93.8 predicted, -4.5) 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]