Solar Terrestrial Activity Report

Last major update issued on November 12, 2005 at 05:50 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 very quiet to quiet on November 11. Solar wind speed ranged between 346 and 392 (all day average 361) km/sec under the influence of a weak low speed stream from CH196.

Solar flux measured at 20h UTC on 2.8 GHz was 78.6. The planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8)
Three hour interval K indices: 12112211 (planetary), 12111201 (Boulder).

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

At midnight the visible solar disk was spotless. The solar flare activity level was very low. No C class events were recorded during the day. An active region is at the central east limb and has caused a significant increase in the background x-ray flux since noon on Nov.11.

Coronal mass ejections (CMEs)

November 9-11: 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 could rotate to an Earth facing position on November 13.

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 quiet to unsettled on November 12 due to effects from CH196 and mostly quiet on November 13-15.

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) 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). The usual east coast US stations were heard at poor to fair signal levels, propagation was best to Venezuela and Colombia.

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.

Monthly solar cycle data

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.