Last major update issued on February 15, 2006 at 04:40 UTC.
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[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update February 4, 2006)]
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The geomagnetic field was inactive to very quiet on February 14. Solar wind speed ranged between 290 and 362 (all day average 335 km/sec. An increase in wind speed was observed late in the day and early on February 15 as the stream from CH211 arrived
Solar flux measured at 20h UTC on 2.8 GHz was 77.3. The planetary A
index was 1 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 00000001 (planetary), 00001001 (Boulder).
The background x-ray flux is at the class A1 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Spotted regions not numbered by NOAA/SEC:
[S624] This region emerged near the northeast limb on February 13. Location at midnight: N05E56.
[S625] A new region emerged in the southeast quadrant on February 14. Location at midnight: S07E35.
February 12-14: No obviously fully or partly Earth directed CMEs were observed.
Coronal hole history (since late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A coronal hole (CH211) in the southern hemisphere was in an Earth facing position on February 12.
Processed SOHO/EIT 284 image at 01:06 UTC on February 15. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on February 15-16 due to weak effects from CH211 and quiet on February 17-19.
|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.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: WLAM Lewiston ME. Compared to the previous night fewer stations from North America were audible and most had weaker signals.
Compare to the previous day's image.
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SEC. 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 SEC or where SEC has observed no spots. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.
|Active region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
|Total spot count:||0||6|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2005.08||90.5||36.4||(27.6 predicted, -1.5)|
|2005.09||91.1||22.1||(25.8 predicted, -1.8)|
|2005.10||77.0||8.5||(24.0 predicted, -1.8)|
|2005.11||86.3||18.0||(21.6 predicted, -2.4)|
|2005.12||90.7||41.2||(18.7 predicted, -2.9)|
|2006.01||83.4||15.4||(15.6 predicted, -3.1)|
|2006.02||76.1 (1)||1.9 (2)||(12.5 predicted, -3.1)|
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/SEC) sunspot number. The official international sunspot number is typically 30-50% lower.
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.