Solar Terrestrial Activity Report

Last major update issued on November 21, 2003 at 01:30 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 12, 2003)]

Recent activity

The geomagnetic field was quiet to extremely severe storm on November 20. Solar wind speed ranged between 431 and 915 km/sec. A strong solar wind shock was observed at SOHO at 07:27 UTC, this was the arrival of the double full halo CME observed on November 18. The interplanetary magnetic field was extremely strongly southwards for several hours after the solar storm reached the Earth. 

Solar flux measured at 20h UTC on 2.8 GHz was 175.2. The planetary A index was 117 (STAR Ap - based on the mean of three hour interval ap indices: 117.4).
Three hour interval K indices: 13677897 (planetary), 14567885 (Boulder).

The background x-ray flux is at the class B7 level.

At midnight there were 5 spotted regions on the visible disk. Solar flare activity was high. A total of 11 C and 3 M class events were recorded during the day. Some flares had a likely origin behind the southeast limb, C4.3 at 04:40, C4.1 at 10:18 UTC and a few small C class events.

Region 10501 decayed slowly in the southern spot section. There are still 2 magnetic delta structures, one each in the two main penumbrae. M class flares are possible. Flares: C2.1 at 01:19, M1.4/1N at 02:12, C3.8 at 07:28, M9.6/2B at 07:47 (associated with a weak type IV radio sweep) and M5.8 at 23:53 UTC.
Region 10505 developed slowly and quietly.
Region 10506 developed slowly adding several new spots in the northern part.
Region 10507 was mostly unchanged and quiet. A major flare is possible as there is a strong magnetic delta structure within the main penumbra. Flares: C8.6 at 19:29 and C1.3 at 22:42 UTC. The C8 event was associated with a large filament eruption to the west of the region. There may have been a CME as well, image analysis has not yet been performed.
Region 10508 was generally unchanged, slow decay was observed in the northernmost penumbra. A major flare is possible.

Coronal mass ejections (CMEs)

November 20: A faint full halo CME was observed after the M9.6 flare in region 10501, in LASCO C2 images the CME was first visible at 08:06 UTC. This CME could reach the Earth during the latter half of November 22.

November 19: No partly or fully earth directed CMEs observed.

November 18: A fairly faint full halo CME was observed after an M3.2 long duration event in region 10501 at 07:52 UTC. A faster and brighter halo CME was observed in LASCO images following an M3.9 long duration event in region 10501 at 08:31 UTC. These CMEs will combine into one and could reach Earth early on November 20.

A bright, fast and very large partial halo CME was observed after the long duration M4.5 event in old region 10486 just behind the southeast limb at 10:11 UTC.

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 could rotate into a geoeffective position on November 20-21.

Processed SOHO/EIT 284 image at 13:05 UTC on November 20. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be unsettled to major storm on November 21 and unsettled to minor storm on November 22. A fairly weak high speed stream from coronal hole CH68 could influence the geomagnetic field on November 23-25.

Long distance low 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 poor to very poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay with a weak signal. Some stations from Brazil noted on other frequencies].

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
Location at midnight Area Classification Comment
10501 2003.11.13 15 17 N02W18 0340 DKI beta-gamma-delta
10502 2003.11.14     N07W35     plage
10503 2003.11.15     N17W57     plage
10505 2003.11.17 3 4 S23E19 0030 CRO classification was CSO
at midnight, area 0020
10506 2003.11.18 10 18 S23E44 0120 DSO classification was DAI
at midnight
10507 2003.11.18 22 25 N07E49 0840 DKI beta-gamma-delta
classification was DKC
at midnight
10508 2003.11.19 18 31 S20E58 0680 DKO beta-gamma
classification was DAC
at midnight, area 0450
S303 emerged on
    N12W79     plage
Total spot count: 68 95
SSN: 118 145

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)
2003.11 125.6 (1) 47.5 (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.

[DX-Listeners' Club]