Solar Terrestrial Activity Report

Last major update issued on November 17, 2005 at 05:45 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 9, 2005)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 9, 2005)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 9, 2005)]
[Historical solar and geomagnetic data charts 1954-2004 (last update February 1, 2005)]
[Archived reports (last update November 2, 2005)]

Recent activity

The geomagnetic field was inactive to quiet on November 16. Solar wind speed ranged between 298 and 358 (all day average 330) km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 94.0. The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.0)
Three hour interval K indices: 02001111 (planetary), 02010110 (Boulder).

The background x-ray flux is at the class B1 level.

At midnight there were 2 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 10822 decayed further in the trailing and intermediate spot sections while the leading penumbra became even larger. A minor M class flare is possible. Flares: C5.9 at 12:13 UTC.

Spotted regions not numbered by NOAA/SEC:
[S605] This region emerged on November 16 in the northwest quadrant. Location at midnight: N11W68

Coronal mass ejections (CMEs)

November 14-15: No obvious fully or partly Earth directed CMEs were observed.
November 16: A filament eruption was observed in the northwest quadrant near the equator beginning at 13:48 UTC in SOHO EIT images. The peak activity was observed 15-16h UTC and a slow partial halo CME could be seen in LASCO C3 images after 18:42 UTC. This CME spanned about 180 degrees at midnight UTC and could reach Earth.

Coronal holes

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 small trans equatorial coronal hole (CH198) was in an Earth facing position on November 16.

Processed SOHO/EIT 284 image at 19:06 UTC on November 16. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be quiet to unsettled on November 17-19. There is a chance a low speed stream from CH198 could arrive on Nov.19, as could the partial CME observed on Nov.16. If any of these arrive we could see unsettled to active conditions during the latter half of Nov.19 and on Nov. 20.

Coronal holes (1) Coronal mass ejections (2) M and X class flares (3)
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. When the high speed stream has arrived the color changes to green.
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.


Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair to good. 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 and WWNN Pompano Beach FL. Many stations from the US east coast were audible, some with quite good signals. Particularly the 50 kW stations from New York were good.

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
Location at midnight Area Classification Comment
10822 2005.11.12 48 26 S08E28 0740 FKI beta-gamma
S605 2005.11.16   1 N11W68 0010 AXX  
Total spot count: 48 27  
SSN: 58 47  

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)
2004.09 103.1 27.7 37.5 (-1.7)
2004.10 105.9 48.0 35.9 (-1.6)
2004.11 113.2 43.5 35.3 (-0.6)
2004.12 94.5 17.9 35.2 (-0.1)
2005.01 102.2 31.3 34.6 (-0.6)
2005.02 97.2 29.2 33.9 (-0.7)
2005.03 89.9 24.5 33.5 (-0.4)
2005.04 86.0 24.4 31.6 (-1.9)
2005.05 99.3 42.6 (28.9 predicted, -2.7)
2005.06 93.7 39.6 (27.3 predicted, -1.6)
2005.07 96.4 39.9 (26.1 predicted, -1.2)
2005.08 90.5 36.4 (24.3 predicted, -1.8)
2005.09 91.1 22.1 (22.2 predicted, -2.1)
2005.10 77.0 8.5 (20.2 predicted, -2.0)
2005.11 82.6 (1) 13.1 (2) (17.8 predicted, -2.4)

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]