Solar Terrestrial Activity Report

Last major update issued on November 3, 2004 at 05:15 UTC. Minor update posted at 17:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update October 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October 2, 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 inactive to quiet on November 2. Solar wind speed ranged between 332 and 358 km/sec. What was likely the early part of the low speed stream from coronal hole CH122 was observed at ACE at 18h UTC. The interplanetary magnetic field has been mostly northwards afterwards and no significant effects on the geomagnetic field has been observed.

Solar flux measured at 20h UTC on 2.8 GHz was 133.1. The planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.5).
Three hour interval K indices: 10021221 (planetary), 10122321 (Boulder).

The background x-ray flux is at the class B6 level.

At midnight there were 5 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 8 C class events was recorded during the day. Region 10687 behind the northwest limb produced a C6.9 flare at 01:43 and a C2.5 long duration event peaking at 13:58 UTC. 

Region 10690 decayed further and lost penumbra on the single spot. The region could become spotless today.
Region 10691 decayed early in the day, then developed slowly. Minor M class flares are possible. Flares: C9.8 at 09:47 and C1.2 at 19:18 UTC. (Both flares were reported by SEC as occurring in region 10689, video of the events has the location in the western part of region 10691.) An M2 flare was observed in this region early on November 3.
Region 10693 decayed significantly in the intermediate and trailing spot sections. Flare: C1.8 at 01:21 UTC.
Region 10695 was quiet and stable.
Region 10696 developed quickly and has minor M class flare potential. Flare: C1.2 at 19:18 UTC. This region was the source of a long duration M1.6 event peaking at 03:35 UTC on November 3.

Comment added at 17:55 UTC on November 3: Region 10696 continues to develop and produced a major M5.0 flare at 15:47 UTC. This event was associated with a strong type II radio sweep and a fast CME mainly over the east limbs. The CME could become full halo within the next couple of hours. The M1.6 flare early today in region 10696 was associated with a strong type II and a moderate type IV radio sweep. The CME observed afterwards was fairly fast and may marginally have become full halo. There is a fair chance that both these CMEs will impact the magnetosphere on November 5 and cause unsettled to major storm conditions. Further major activity in region 10696 will increase the chance of a large proton event.

Coronal mass ejections (CMEs)

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, possibly late on November 3.
October 31 and November 2
: 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

A trans equatorial coronal hole (CH122) was in a geoeffective position on October 30-31. An extension (CH123) of the northern polar coronal hole will be in a geoeffective position on November 3-4. 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 3. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be quiet to unsettled on November 3-4 due to effects from coronal hole CH122. Mostly quiet is likely on November 5.

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 fair to good. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant stations tonight: WLAM Lewiston ME and WWNN Boca Raton FL. On other frequencies propagation was best towards the southeasternmost parts of North America and towards Cuba. There were 3 stations on 850 kHz with WFTL Ft.Lauderdale FL dominating over WEEI Boston MA. Radio Reloj (Cuba) occasionally had the best signal. WIOD Miami FL on 610 had an impressive signal. Florida signals were noted on several other frequencies as well (i.e. 970, 1060 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
Location at midnight Area Classification Comment
10689 2004.10.21 1   N10W81 0000 AXX spotless
10690 2004.10.22 1 1 S01W67 0010 AXX  
10691 2004.10.23 6 10 N12W67 0170 DAO beta-gamma
10693 2004.10.27 34 37 S14W05 0720 EKC  
10694 2004.10.28     N14W42     plage
10695 2004.10.30 3 4 S12E27 0060 DAO  
10696 2004.11.01 5 13 N08E47 0110 DAO beta-gamma
classification was DAC
at midnight, area 0200
Total spot count: 50 65
SSN: 110 115

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)
2004.11 134.3 (1) 8.5 (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]