Solar Terrestrial Activity Report

Last major update issued on November 24, 2003 at 05:10 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 4, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 4, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 4, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update November 22, 2003)]

Recent activity

The geomagnetic field was unsettled to minor storm on November 23. Solar wind speed ranged between 466 and 601 km/sec under the influence of a high speed stream from coronal hole CH68.

Solar flux measured at 20h UTC on 2.8 GHz was 178.2. The planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.9).
Three hour interval K indices: 35433344 (planetary), 35433234 (Boulder).

The background x-ray flux is at the class B6 level.

At midnight there were 6 spotted regions on the visible disk. Solar flare activity was low. A total of 7 C class events were recorded during the day. Optically uncorrelated events: C1.0 at 00:14 and C1.2 at 12:09 UTC.

Region 10501 decayed further and was quiet.
Region 10506 became spotless. Flare: C1.5 at 16:04 UTC.
Region 10507 developed in the northern part of the main penumbral area while slow decay was observed in the southern part. There is a strong magnetic delta structure within the main penumbra. Major flares are possible. Flare: C1.0 at 01:28 UTC.
Region 10508 developed slowly and quietly. The northernmost spots were split off into region S309 as they appear to be a separate bipolar group. Flares: C1.2 at 17:50 and C3.0 at 23:53 UTC.

Spotted regions not numbered by NOAA/SEC:
[S308] This region rotated into view the southeast limb on November 22. Location at midnight: S11E67.
[S309] This region was split off from region 10508 . Location at midnight: S13E16.
[S310] This region rotated into view at the southeast limb on November 23. Location at midnight: S23E73.Flare: C1.0 at 22:15 UTC.

Coronal mass ejections (CMEs)

November 21-23: No partly or fully earth directed CMEs 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 coronal hole (CH68) in the northern hemisphere was in a geoeffective position on November 20-21. A new and developing coronal hole (CH69) in the southern hemisphere was in a geoeffective position on November 22.

Processed SOHO/EIT 284 image at 01:05 UTC on November 24. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be unsettled to active on November 24-25 due to high speed streams from coronal holes CH68 and CH69, quiet to unsettled is likely on November 26-27.

Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is very poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay with a weak signal. WDHP on 1620 kHz was heard as well].

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.

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% less.

This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.