Solar Terrestrial Activity Report

Last major update issued on November 27, 2003 at 04:30 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 quiet to unsettled on November 26. Solar wind speed ranged between 450 and 557 km/sec as the high speed coronal stream weakened further.

Solar flux measured at 20h UTC on 2.8 GHz was 170.9. The planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 10.0).
Three hour interval K indices: 22223332 (planetary), 12212222 (Boulder).

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

At midnight there were 9 spotted regions on the visible disk. Solar flare activity was low. A total of 2 C class events were recorded during the day.

Region 10506 reemerged with several spots.
Region 10507 decayed slowly and quietly. An isolated M class flare is possible as there is still a magnetic delta structure in the northern part of the largest penumbra.
Region 10508 decayed moderately quickly. Flares: C1.2 at 03:16 and C1.7 at 16:18 UTC.
Region 10509 developed slowly in and near the main penumbra.
Region 10510 developed slowly and quietly. This is currently the brightest region on the visible disk.
Region 10511 developed and more than doubled its penumbral area.
Region 10512 added a few spots and is still simply structured.
New region 10513 rotated into view at the northeast limb early in the day.

Spotted regions not numbered by NOAA/SEC:
[S313] This region emerged in the southwest quadrant to the west of region 10508. Location at midnight: S15W34.

Coronal mass ejections (CMEs)

November 24-26: 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

No obvious coronal holes are currently approaching geoeffective positions. The southernmost extensions of the northern polar coronal hole could be marginally geoeffective.

Processed SOHO/EIT 284 image at 01:05 UTC on November 27. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 27-30.

Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to very poor. Propagation along long distance north-south paths is poor to very poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Cadena Peruana de Noticias. A few North American stations were noted, one of them was WWZN Boston on 1510 with a weak signal].

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.