Solar Terrestrial Activity Report

Last major update issued on November 12, 2004 at 04:20 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 4, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 4, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 4, 2004)]
[Historical solar and geomagnetic data charts 1954-2004 (last update November 8, 2004)]
[Archived reports (last update November 8, 2004)]

Recent activity

The geomagnetic field was quiet to minor storm on November 11. Solar wind speed ranged between 543 and 662 km/sec. A moderate solar wind shock was observed at 16:42 UTC at ACE with a quick increase in solar wind speed from 550  to 600 km/sec. This was likely the arrival of the CME observed after a flare in region 10696 during the afternoon of November 9.

Solar flux measured at 20h UTC on 2.8 GHz was 94.9. The planetary A index was 23 (STAR Ap - based on the mean of three hour interval ap indices: 22.6).
Three hour interval K indices: 45442324 (planetary), 45342334 (Boulder).

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

At midnight there were 4 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 10696 decayed further and rotated partly out of view at the northwest limb. There is a possibility of an M class flare today and tomorrow while the region is at and just behind the northwest limb. Flare: C1.1 at 15:54 UTC.
Region 10699 appears to be slowly decaying.
New region 10700 first emerged in the northeast quadrant on November 8 and became spotless the next day. The region reemerged on November 11 while near the center of the visible disk. Slow decay was observed late in the day.
New region 10701 rotated partly into view at the southeast limb on November 10 and was numbered by SEC the next day.

Coronal mass ejections (CMEs)

November 11: No LASCO images available as I write this.
November 10
: Another very fast CME was associated with the major X2.8 flare in region 10696 early in the day. This CME could reach Earth on November 12.

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

Recurrent coronal hole CH126 in the southern hemisphere is very poorly defined and was in a geoeffective position on November 10-11. Recurrent coronal hole CH127 in the northern hemisphere will likely rotate into a geoeffective position on November 16-17.

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 unsettled to major storm on November 12 and quiet to unsettled on November 13-14.

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 useless. Propagation along long distance north-south paths is very poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay was occasionally noted with a very weak signal. The only other trans Atlantic station heard was Rádio Sociedade on 740 kHz.

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
10696 2004.11.01 20 7 N08W76 0460 EAC beta-gamma-delta
classification was EAO
at midnight, area 0260
10699 2004.11.09 1 1 S14E38 0030 HSX classification was HRX
at midnight, area 0020
10700 2004.11.11 7 3 N04W02 0020 DSO formerly region S471
classification was BXO
at midnight, area 0010
10701 2004.11.11 2 4 S16E70 0080 CSO formerly region S473
classification was CAO
at midnight
S472 emerged on
2004.11.09
    S12W54     plage
Total spot count: 30 15
SSN: 70 55

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)
2003.08 122.1 72.7 60.0 (-1.7)
2003.09 112.2 48.7 59.5 (-0.5)
2003.10 151.7 65.5 58.2 (-1.3)
2003.11 140.8 67.3 56.7 (-1.5)
2003.12 114.9 46.5 54.8 (-1.9)
2004.01 114.1 37.3 52.0 (-2.8)
2004.02 107.0 45.8 49.3 (-2.7)
2004.03 112.0 49.1 47.1 (-2.2)
2004.04 101.2 39.3 45.5 (-1.6)
2004.05 99.8 41.5 (42.8 predicted, -2.7)
2004.06 97.4 43.2 (40.0 predicted, -2.8)
2004.07 119.1 51.0 (38.2 predicted, -1.8)
2004.08 109.6 40.9 (36.6 predicted, -1.6)
2004.09 103.1 27.7 (34.7 predicted, -1.9)
2004.10 105.9 48.4 (32.5 predicted, -2.2)
2004.11 126.4 (1) 36.6 (2) (31.0 predicted, -1.5)

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 some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.


[DX-Listeners' Club]