Solar Terrestrial Activity Report

Last major update issued on November 13, 2005 at 06:20 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 quiet to unsettled on November 12. Solar wind speed ranged between 364 and 440 (all day average 399) km/sec under the influence of a low speed stream from CH196.

Solar flux measured at 20h UTC on 2.8 GHz was 83.1. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.8)
Three hour interval K indices: 23223321 (planetary), 23333221 (Boulder).

The background x-ray flux is at the class C1 level.

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

New region 10822 rotated partly into view at the southeast limb. This region is complex and has at least one magnetic delta structure. M class flares are likely, even a major flare is a possibility. Flares: C2.5 at 14:58, C1.7 at 15:20 and C9.5 at 19:33 UTC.

Coronal mass ejections (CMEs)

November 10-12: No obvious fully or partly Earth directed CMEs were observed.

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 recurrent coronal hole (CH196) in the northern hemisphere was in an Earth facing position on November 7-8. A coronal hole (CH197) in the southern hemisphere was likely in an Earth facing (potentially geoeffective) position on November 12-13.

Processed SOHO/EIT 284 image at 01:06 UTC on November 13. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 13 and mostly quiet on November 14-15. Late on Nov.15 or on Nov.16 a high speed stream from CH197 could reach Earth and cause unsettled to active conditions.

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.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). Propagation was again uninspiring with some of the usual east coast US stations noted a poor to fair levels and with some signals from Venezuela, Colombia and Cuba.

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
10821 2005.11.08     S14W71     plage
10822 2005.11.12 1 7 S04E81 0120 HSX beta-gamma-delta
classification was EKO at midnight, area 0320
S602 2005.11.06     S06W74     plage
S603 2005.11.06     N05W62     plage
Total spot count: 0 0  
SSN: 0 0  

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 78.9 (1) 8.7 (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]