Solar Terrestrial Activity Report

Last major update issued on November 14, 2006 at 05:25 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 12, 2006)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 12, 2006)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 12, 2006)]
[Historical solar and geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update November 12, 2006)]

Recent activity

The geomagnetic field was very quiet on November 13. Solar wind speed ranged between 357 and 467 km/s (all day average 408 km/s - decreasing 105 km/s from the previous day).

Solar flux measured at 20h UTC on 2.8 GHz was 95.2. The planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.8). Three hour interval K indices: 00100001 (planetary), 00200100 (Boulder).

The background x-ray flux is at the class A6 level.

At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 1 C class event was recorded during the day.

Region 10923 did not change much. The huge penumbra is now almost symmetrical and only a few small spots are visible outside of that penumbra. Flare: C1.0 at 06:42 UTC.
New region 10924 rotated into view on November 12 and was numbered by NOAA/SEC the following day.

Spotted regions not numbered by NOAA/SEC:
[S682] This region emerged quickly in the southeast quadrant to the west southwest of region 10924 on November 13. The region was decaying late in the day. Note that SEC/NOAA has mistakenly included this region in region 10924. Location at midnight: S08E53

Coronal mass ejections (CMEs)

November 11-13: No obvious partly or fully Earth directed CMEs were detected in LASCO imagery.

Coronal holes

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

No obvious coronal holes are currently in or near an Earth facing position. A weak coronal structure is just west of region  10923, this is perhaps the remains of CH244.

Processed SOHO/EIT 284 image at 01:06 UTC on November 12. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be mostly quiet on November 14-15. The quiet conditions could extend for several more days, however, there is some uncertainty as to whether a weak stream from what was CH244 during the previous rotation could arrive on November 16-17.

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.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to occasionally fair. Propagation on long distance northeast-southwest paths is poor.

Monitoring remarks from a location near N58E06: Propagation to North America was unimpressive. Although stations like 1480 WSAR and 1370 WDEA were audible, signals were generally rather weak.

Active solar regions (Recent map)

\

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
spot
count
STAR
spot
count
Location at midnight Area Classification Comment
10923 2006.11.08 7 6 S05E07 0640 CKO  
10924 2006.11.13 3 2 S07E59 0070 CAO formerly region S681
classification was HAX at midnight, area 0050
Location: S05E62
S682 2006.11.13   5 S08E53 0030 CAO  
Total spot count: 10 13  
SSN: 30 43  

Monthly solar cycle data

Month Average solar
flux at Earth
International sunspot number Smoothed sunspot number
2000.04 184.2 125.5 120.8
cycle 23 sunspot max.
2000.07 202.3 170.1 119.8
2001.12 235.1 132.2 114.6 (-0.9)
2005.08 90.5 36.4 27.4 (-1.7)
2005.09 91.1 21.9 25.8 (-1.6)
2005.10 77.0 8.7 25.5 (-0.3)
2005.11 86.3 18.0 24.9 (-0.6)
2005.12 90.7 41.1 23.0 (-1.9)
2006.01 83.4 15.3 20.8 (-2.2)
2006.02 76.5 4.9 18.6 (-2.2)
2006.03 75.4 10.6 17.3 (-1.3)
2006.04 89.0 30.2 17.1 (-0.2)
2006.05 80.9 22.2 (16.8 predicted, -0.3)
2006.06 76.5 13.9 (15.1 predicted, -1.7)
2006.07 75.7 12.2 (13.2 predicted, -1.9)
2006.08 79.0 12.9 (12.7 predicted, -0.5)
2006.09 77.8 14.5 (12.6 predicted, -0.1)
2006.10 74.3 10.4 (11.5 predicted, -1.1)
2006.11 89.1 (1) 15.8 (2) (10.1 predicted, -1.4)

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.


[DX-Listeners' Club]