Last major update issued on February 16, 2010 at 04:55 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-23 (last update October 4, 2007)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 4, 2007)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October 4, 2007)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports (last update January 3, 2010)]
The geomagnetic field was quiet to active on February 15. Solar wind speed ranged between 282 and 344 km/s. A disturbance, which was likely related to the arrival of the CME observed after the M8 flare on Feb.12, arrived at ACE near 17:30 UTC.
Solar flux measured at 20h UTC on 2.8 GHz was 87.6. The planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 13.5). Three hour interval K indices: 33121244 (planetary), 34331243 (Boulder).
The background x-ray flux is at the class A8 level.
At midnight there were 2 spotted regions on the visible solar disk.
Region 11046 decayed slowly and quietly.
Region 11048 was mostly unchanged. Occasional C flares are possible. Flare: C1.9 at 01:16 UTC.
February 13-15: No obvious Earth directed CMEs were observed in LASCO images.
Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A recurrent coronal hole (CH392) in the northern hemisphere was in an Earth facing position on February 11-12. A new coronal hole (CH393) in the southern hemisphere was in an Earth facing position on February 15.
Processed SOHO/EIT 195 image at 23:12 UTC on February 15. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to active on February 16 due to CME and coronal hole effects. Quiet conditions are likely on February 17 and quiet to unsettled on February 18-19 as another coronal hole stream becomes geoeffective.
|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. When the high speed stream has arrived the
color changes to green.
2) Effects from a CME are likely to be observed at 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.
Compare to the previous day's image.
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.
|Active region||Date numbered||SWPC
|Location at midnight||Area||SWPC
|11048||2010.02.13||3||3||N21E50||0010||BXO||classification was CSO at midnight, area 0030|
|Total spot count:||7||6|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average Ap
cycle 23 sunspot max.
|2009.07||68.2||3.5||3.6 (+0.9)||5.49 / 4.55|
|2009.08||67.3||0.0||(5.0 predicted, +1.4)||5.70 / 4.89|
|2009.09||70.5||4.2||(6.8 predicted, +1.8)||3.88 / 3.61|
|2009.10||72.6||4.6||(8.7 predicted, +1.9)||3.66 / 3.56|
|2009.11||73.6||4.2||(10.7 predicted, +2.0)||2.45 / 2.63|
|2009.12||76.7||10.6||(12.9 predicted, +2.2)||1.41 / 1.92|
|2010.01||81.1||13.1||(15.4 predicted, +2.5)||2.93 / 3.07|
|2010.02||86.1 (1)||19.0 (2)||(18.3 predicted, +2.9)||(5.14)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SWPC) sunspot number. The official international sunspot number is typically 30-50% lower.
3) Running average based on the daily SWPC ap indices. Values in red are based on official NGDC ap indices.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.