Solar Terrestrial Activity Report [Image] Last update February 4, 2001 at 05:50 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 2, 2001) - Cycle 23 peaked in April 2000?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet on February 3. Solar wind speed ranged between 332 and 381 km/sec. Solar flare activity was low. Solar flux was 163.6, the planetary A index was 2 (3-hour K indices: 1000 1110, Boulder K indices: 1000 1010). Region 9325 was quiet and stable, as were regions 9327 and 9329. Region 9329 is spotless early on February 4. Region 9330 was mostly unchanged and could produce minor M class flares. Regions 9332 and 9333 were quiet and stable. Region 9332 is spotless early on February 4. Region 9334 was mostly quiet and stable. M class flares are possible. New region 9335 rotated into view at the northeast limb and could produce isolated minor M class flares. New region 9336 emerged in the southeast quadrant near the central meridian, the region is spotless early on February 4. New region 9337 rotated partly into view at the southeast limb. Flares and CMEs Only 1 C class event was recorded on February 3, it was a long duration C1.3 flare peaking at 16:19 UT. The background x-ray flux is at the class B6 level. Coronal holes An isolated coronal hole in the northern hemisphere was in a geoeffective position on February 3-4. Forecast The geomagnetic field is expected to be mostly quiet on February 4-5. A coronal stream is expected to influence the field from February 6 and could cause unsettled to active conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 9325 2001.01.25 1 N11W60 0000 AXX 9327 2001.01.27 5 N18W47 0040 DAO 9329 2001.01.29 3 S09W14 0010 BXO 9330 2001.01.30 17 N26E18 0160 ESO 9331 2001.01.30 N13W26 plage 9332 2001.01.30 4 N09W32 0020 CRO 9333 2001.02.01 3 N26W39 0030 CAO 9334 2001.02.01 9 N11E54 0210 ESO 9335 2001.02.03 5 N09E68 0100 DAO 9336 2001.02.03 1 S10W01 0000 AXX 9337 2001.02.03 1 S27E76 0000 AXX Total number of sunspots: 49 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.11 191.5 133.2 111.0 (+3.2) 1999.12 169.8 84.6 111.1 (+0.1) 2000.01 158.1 90.1 112.9 (+1.8) 2000.02 174.1 112.9 116.8 (+3.9) 2000.03 208.2 138.5 119.9 (+3.1) 120.8 (+0.9) 2000.04 184.2 125.5 cycle 23 peak candidate 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 170.1 119.8 (+1.1) 2000.08 163.0 130.5 (119.7 predicted, -0.1) 2000.09 182.1 109.7 (118.4 predicted, -1.3) 2000.10 167.4 100.1 (116.7 predicted, -1.7) 2000.11 178.8 106.5 (114.8 predicted, -1.9) 2000.12 173.6 104.5 (112.2 predicted, -2.6) 2001.01 166.6 95.7 (108.7 predicted, -3.5) 2001.01 163.6 (1) 14.3 (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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]