Solar Terrestrial Activity Report

Last major update issued on November 26, 2003 at 05:00 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 25. Solar wind speed ranged between 494 and 706 km/sec. A fairly weak high speed stream from coronal hole CH69 peaked early in the day.

Solar flux measured at 20h UTC on 2.8 GHz was 170.7. The planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 14.5).
Three hour interval K indices: 33333332 (planetary), 33334332 (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 5 C class events were recorded during the day.

Region 10507 decayed slowly. An isolated major flare is possible as there is still a magnetic delta structure in the northern part of the main penumbra. Flares: C2.2 long duration event peaking at 10:03 and C1.2 at 11:46 UTC.
Region 10508 decayed slowly. Several of the southernmost spots disappeared. Flares: C3.0 at 06:02 and C1.3 at 13:29 UTC.
Region 10509 lost most of the small spots which emerged the day before. Flare: C1.2 at 02:15 UTC.
Region 10510 developed slowly and quietly.
New region 10511 emerged late on November 24 in the southeast quadrant and was numbered by SEC the next day.
New region 10512 emerged in the northeast quadrant on November 24 and was numbered by SEC the next day.

Coronal mass ejections (CMEs)

November 23-25: 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.

Processed SOHO/EIT 284 image at 01:06 UTC on November 26. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 26-29.

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].

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.

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
10501 2003.11.13 1   N04W85 0120 HSX rotated out of view
10505 2003.11.17     S22W47     plage
10506 2003.11.18 2   S22W18 0010 BXO spotless
10507 2003.11.18 41 42 N09W14 0660 EKC beta-gamma-delta
10508 2003.11.19 52 39 S16W06 0270 EAC  
10509 2003.11.24 10 4 S10E43 0120 CSO  
10510 2003.11.24 7 19 S22E50 0080 DSO classification was CAO
at midnight
10511 2003.11.25 6 15 S14E24 0040 DSO formerly region S312
classification was DAO
at midnight
10512 2003.11.25 3 6 N06E31 0020 CSO formerly region S311
Total spot count: 122 125
SSN: 202 185

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)
2002.10 167.0 97.5 90.5 (-4.1)
2002.11 168.7 95.5 85.2 (-5.3)
2002.12 157.2 80.8 82.0 (-3.2)
2003.01 144.0 79.7 80.9 (-1.1)
2003.02 124.5 46.0 78.5 (-2.4)
2003.03 131.4 61.1 74.1 (-4.4)
2003.04 126.4 60.0 70.3 (-3.8)
2003.05 115.7 55.2 (66.8 predicted, -3.5)
2003.06 129.3 77.4 (63.0 predicted, -3.8)
2003.07 127.7 85.0 (59.3 predicted, -3.7)
2003.08 122.1 72.7 (56.3 predicted, -3.0)
2003.09 112.2 48.8 (54.3 predicted, -2.0)
2003.10 151.7 65.6 (51.6 predicted, -2.7)
2003.11 135.7 (1) 72.9 (2) (48.9 predicted, -2.7)

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.


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