Solar Terrestrial Activity Report

Last major update issued on November 4, 2004 at 04:45 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 August 28, 2004)]
[Archived reports (last update October 30, 2004)]

Recent activity

The geomagnetic field was quiet to active on November 3. Solar wind speed ranged between 321 and 416 km/sec. A low speed stream from coronal hole CH122 caused a minor disturbance during the latter half of the day.

Solar flux measured at 20h UTC on 2.8 GHz was 135.9. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.8).
Three hour interval K indices: 00032334 (planetary), 11042323 (Boulder).

The background x-ray flux is at the class B4 level.

At midnight there were 4 spotted regions on the visible solar disk. The solar flare activity level was high. A total of 14 C and 4 M class events was recorded during the day.

Region 10691 rotated partly out of view at the northwest limb and remains capable of producing minor M class flares. Flares: M2.8/1F at 01:33, C1.5 at 06:44, C1.5 at 07:18, C1.5 at 07:30, C1.2 at 07:58, C1.4 at 08:40, C5.3 at 08:58, C8.4 at 09:09, C1.8 at 11:05, C2.7 at 13:48 and C3.8 at 16:56 UTC.
Region 10693 decayed further in the trailing spot section while only minor decay was observed in the leading spots. The region is still fairly simple structured magnetically. Flare: C2.1 at 09:31 UTC.
Region 10695 decayed slowly with penumbra disappearing from the northernmost spot.
Region 10696 developed quickly and could produce an X class flare. The region is very compact and complex with 3 magnetic delta structures within a single very large penumbra. Positive polarity spots in the northwest, north and east have merged with the penumbra which previously had only negative polarity spots. Further major flaring will increase the chance of a proton flare. Flares: long duration M1.6/1N (associated with strong type II and a moderate type IV radio sweeps and a halo CME) peaking at 03:35, major M5.0 (associated with strong type II and a moderate type IV radio sweeps and a fast, full halo CME) at 15:47 and M1.0 at 18:26 UTC.

Coronal mass ejections (CMEs)

November 3: A halo CME was observed after an M1 event in region 10696 early in the day. While this CME was not aimed directly at Earth, a sideways glancing impact is possible late on November 5 or on November 6. A large, fast, full halo CME was observed after an M5 event in region 10696 during the afternoon. Again, this CME was not aimed directly at Earth. However, much more mass was observed over the west limbs compared to the event earlier in the day. This CME is likely to impact Earth's magnetosphere sometime between noon on November 5 and noon on November 6 and cause active to major storm conditions. 
November 2
: No obviously Earth directed CMEs observed.
November 1
: A faint full halo CME was observed in LASCO C3 images following an M1.1 proton event in region 10691 early in the day. This CME could reach Earth on November 4.

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 trans equatorial coronal hole (CH122) was in a geoeffective position on October 30-31. An extension (CH123) of the northern polar coronal hole was in a geoeffective position on November 3. A recurrent coronal hole (CH124) in the southern hemisphere will rotate to a geoeffective position on November 4.

Processed SOHO/EIT 284 image at 01:06 UTC on November 4. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be quiet to active on November 4 due to effects from coronal hole CH122. Quiet to unsettled is expected for November 5 until the arrival of CMEs observed on November 3 that day or on November 6. Active to major storm is likely on November 6. Coronal hole effects from CH123 and CH124 are possible on November 7-8.

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.


Long distance low and medium 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 fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela) and Radio Cristal del Uruguay. Radio Belgrano (Argentina) was noted on 1510 kHz. From North America only a few weak signals could be heard at 04h UTC: CJYQ 930, WEEI 850 and WWZN 1510.

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
10690 2004.10.22 1   S01W81 0030 HRX spotless
10691 2004.10.23 10 6 N13W81 0200 DAI beta-gamma
classification was DAO
at midnight, area 0100
10693 2004.10.27 44 31 S15W18 0690 FKC classification was FKO
at midnight
10694 2004.10.28     N14W55     plage
10695 2004.10.30 4 2 S14E12 0050 DAO classification was CSO
at midnight
10696 2004.11.01 14 22 N09E32 0270 DAC beta-delta
very high flare

classification was DKC
at midnight, area 0450
Total spot count: 73 61
SSN: 123 101

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)
2004.11 134.8 (1) 12.6 (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]