Solar Terrestrial Activity Report

Last major update issued on November 23, 2004 at 04:05 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 20, 2004)]

Recent activity

The geomagnetic field was quiet to active on November 22. Solar wind speed ranged between 460 and 582 km/sec, slowly decreasing after 05h UTC.

Solar flux measured at 20h UTC on 2.8 GHz was 106.3. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.5).
Three hour interval K indices: 14431221 (planetary), 23432121 (Boulder).

The background x-ray flux is at the class B3 level.

At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was low. A single C class event was recorded during the day. This was a very long duration C1.1 event peaking at 07:57 and with an origin behind the southeast limb.

Region 10701 decayed slowly and quietly and will rotate out of view at the southwest limb today.
Region 10704 decayed slowly.

Spotted regions not numbered by NOAA/SEC:
[S477] This region was first observed on November 14, then lost its spots. A single spot became visible on Nov. 21. Slow development was observed on November 22. Location at midnight: S04W52.

Coronal mass ejections (CMEs)

November 20-22: No obviously 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

Recurrent coronal hole CH128 in the southern hemisphere was in a geoeffective position on November 21-23.

Processed SOHO/EIT 284 image at 19:06 UTC on November 22. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 23-24. A high speed stream from coronal hole CH128 will likely arrive on November 25 and cause unsettled to active conditions that day becoming quiet to active on November 26-27.

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 very poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Radio Vibración (Venezuela) was heard weakly at times. On other frequencies propagation was best towards Brazil with a strong signal from Rádio Metropolitana on 930 and an unidentified station with religious programming on 580 kHz. The only North American station I could hear was WWZN Boston on 1510 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
10701 2004.11.11 1 1 S17W74 0030 HSX area was 0010
at midnight
10703 2004.11.18     N12W05     plage
10704 2004.11.18 7 6 N13E25 0110 DSO classification was DAO
at midnight, area 0090
S477 emerged on
2004.11.14
  5 S04W52 0020 CAO  
S480 visible on
2004.11.19
    S12E31     plage
Total spot count: 8 12
SSN: 28 42

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)
2004.11 114.4 (1) 55.5 (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]