Solar Terrestrial Activity Report [Image] Last update January 24, 2002 at 03:20 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update January 1, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2002)] [Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 2002)] Recent development The geomagnetic field was quiet to unsettled on January 23. Solar wind speed ranged between 348 and 407 km/sec. Solar flare activity was low. Solar flux was 226.5, the planetary A index was 6 (3-hour K indices: 2012 2332, Boulder K indices: 2122 1312). [General comment: SEC/NOAA managed to observe an incredible 19 spotted regions on January 23. This was more than most other observers. Mt.Wilson, which usually observes more regions than SEC/NOAA, noted 13 spotted regions. This number agrees better with satellite images.] Region 9781 rotated out of view very early in the day and should not have been included in the spot count. Region 9782 rotated quietly off the visible disk. Region 9783 decayed and was mostly quiet. Region 9784 reemerged with a few spots. Region 9785 is rotating quietly out of view at the northwest limb. Region 9786 rotated quietly over the southwest limb. Region 9787 decayed and had at the end of the lost most of the small spots to the northwest of the huge main penumbra. The region is still capable of minor M class flaring. Region 9788 decayed and had lost several of its trailing spots and some of the penumbral area of the leading spots late in the day. SEC/NOAA claims that the region has mixed polarities, there is no evidence of that from recent magnetograms. Region 9789 was spotless. Region 9790 lost its last spot very early in the day but was still included by SEC/NOAA. Region 9791 decayed quietly. Region 9792 reemerged with several spots, then decayed and was spotless by midnight. Region 9793 developed slowly and was mostly quiet. Region 9794 reemerged with a couple of spots. New region 9795 emerged near the northwest limb. New region 9796 emerged in the northeast quadrant near region 9794. New regions 9797, 9798 and 9799 emerged in the southeast quadrant, region 9797 appears to be spotless early on January 24. Flares and CMEs A total of 7 C class events were recorded on January 23. Region 9794 produced a C1.7 flare (with an associated type II radio sweep) at 03:37 and a C3.7 flare (with an associated moderate type II radio sweep) at 13:37 UTC. Region 9787 generated a C1.4 flare at 09:09 and a C2.3 flare at 22:28 UTC, while region 9783 managed a C1.6 flare at 10:00 UTC. The background x-ray flux is at the class C1 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on January 24-26. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9781 2002.01.11 1 S03W95 0030 HAX 9782 2002.01.11 1 N08W88 0060 HAX 9783 2002.01.12 8 S11W65 0140 DAO area too large 9784 2002.01.13 3 S28W73 0030 CAO 9785 2002.01.13 1 N13W79 0080 HSX 9786 2002.01.16 1 S24W86 0060 HAX 9787 2002.01.17 10 S07E06 0440 DKI beta-gamma 9788 2002.01.18 20 N17W14 0170 DAI 9789 2002.01.18 1 N26W55 0010 HRX spotless all day! 9790 2002.01.19 1 N29W28 0010 AXX actually spotless 9791 2002.01.20 5 S02W59 0060 DSO 9792 2002.01.20 5 N03W16 0010 BXO now spotless 9793 2002.01.20 8 S14W10 0020 CSO 9794 2002.01.20 2 N12E23 0010 HSX 9795 2002.01.23 3 N23W60 0040 DSO 9796 2002.01.23 4 N09E18 0030 CSO 9797 2002.01.23 2 S16E32 0020 HSX now spotless 9798 2002.01.23 4 S03E42 0020 CSO 9799 2002.01.23 2 S25E54 0020 BXO Total number of sunspots: 82 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 2000.11 178.8 106.8 112.7 (-1.8) 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 107.6 (+2.8) 2001.05 147.1 96.6 108.7 (+1.1) 2001.06 173.0 134.0 109.8 (+1.1) 2001.07 131.3 82.2 (111.2 predicted, +1.4) 2001.08 162.9 106.8 (111.7 predicted, +0.5) 2001.09 233.2 150.7 (110.7 predicted, -1.0) 2001.10 207.6 125.6 (108.0 predicted, -2.7) 2001.11 210.6 106.5 (106.3 predicted, -1.7) 2001.12 235.1 131.8 (103.0 predicted, -3.3) 2002.01 219.8 (1) 135.8 (2) (99.4 predicted, -3.6) 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 25-40% 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]