Solar Terrestrial Activity Report [Image] Last update May 14, 2000 at 05:55 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 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update May 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update May 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update April 12, 2000)] Recent development The geomagnetic field was quiet to active on May 13. Solar wind speed ranged between 360 and 592 km/sec. Solar flare activity was moderate. Solar flux was 217.3, the planetary A index was 15 (3-hour K indices: 4323 3332, Boulder K indices: 4233 2333). Regions 8983 and 8987 were quiet and stable, both are spotless early on May 14. Region 8989 developed further and could produce C and minor M class flares. Region 8990 developed slowly and could generate M flares. Region 8991 was mostly unchanged and quiet. Region 8992 was quiet and stable. Region 8993 developed slowly and could produce minor M class flares. Region 8994 decayed into spotless plage. Region 8996 continued its development and is a large region capable of producing major flares, even X class flares. Region 8997 was quiet and stable. Region 8998 rotated fully into view and should be capable of producing a minor M flare. New region 8999 rotated partly into view at the northeast limb. This region, or a trailing region, is capable of producing M flares. New region 9000 emerged in the northeast quadrant, the region is spotless early on May 14. New region 9001 emerged in the northwest quadrant near the central meridian. Flares and CMEs A total of 9 C flares and 1 M flare were observed on May 13. An optically unassigned long duration M1.1 event peaked at 01:44 UTC. Region 8996 produced a C7.6 flare at 03:23, a C4.0 flare at 04:34, a C6.7/1F flare at 07:32 and a C3.7 flare at 12:14 UTC. Region 8993 generated a C3.8 flare at 11:01, a C2.9 flare at 20:59 and a long duration C7.4 event peaking at 23:34 UTC. Region 8990 was the source of a C2.8 flare at 11:58 UTC while region 8999 managed a C4.5 flare at 17:49 UTC. May 10: Region 8990 generated the most significant event of the day, a long duration C8.7/2N event peaking at 19:41 UTC. A strong type II sweep and a weak type IV sweep were observed as well. A partial halo CME covering the entire eastern hemisphere was seen in LASCO C2 images. The CME could impact Earth with the most likely impact time being the first half of May 14. The background x-ray flux is at the class C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be unsettled to minor storm on May 14 due to a possible CME impact. 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 8983 20000504 1 N26W67 0000 AXX 8985 20000505 N12W53 plage 8987 20000507 2 N09W75 0000 AXX 8988 20000507 N08W82 plage 8989 20000507 22 N17W40 0400 DKI beta-gamma 8990 20000507 34 N13W21 0360 EKI beta-gamma 8991 20000508 9 N15E07 0040 CSO 8992 20000509 3 N10E22 0030 CAO 8993 20000508 23 S23W45 0200 DAI 8994 20000510 N08W43 plage 8995 20000511 S19W26 plage 8996 20000511 16 S22E57 1210 EKI beta-gamma 8997 20000511 2 S16E37 0020 HSX 8998 20000512 8 S13E66 0260 EAO beta-gamma 8999 20000513 5 N21E67 0040 BXO 9000 20000513 4 N10E14 0010 BXO 9001 20000513 1 N16W05 0000 AXX Total number of sunspots: 130 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.04 117.2 63.9 85.5 (+1.7) 1999.05 148.4 106.3 90.5 (+5.0) 1999.06 169.8 137.7 93.1 (+2.6) 1999.07 165.6 113.5 94.5 (+1.4) 1999.08 170.7 93.7 97.4 (+2.9) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.7 (+5.4) 1999.11 191.5 133.2 (109.8 predicted, +2.1) 1999.12 169.8 84.6 (108.2 predicted, -1.6) 2000.01 158.1 90.2 (108.6 predicted, +0.4) 2000.02 174.1 112.3 (112.0 predicted, +3.4) 2000.03 208.2 138.2 (115.8 predicted, +3.8) 2000.04 184.2 125.3 2000.05 156.2 (1) 62.8 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz.. 2) Unofficial, accumulated value. The official value 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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]