Solar Terrestrial Activity Report

Last major update issued on November 2, 2004 at 04:50 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 quiet on November 1. Solar wind speed ranged between 349 and 432 km/sec, gradually decreasing.

Solar flux measured at 20h UTC on 2.8 GHz was 135.5. The planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1).
Three hour interval K indices: 21112211 (planetary), 31111322 (Boulder).

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

At midnight there were 6 spotted regions on the visible solar disk. The solar flare activity level was moderate. A total of 2 C and 1 M class events was recorded during the day. Region 10687 at and just behind the northwest limb produced a C2.6 flare at 04:22 and a C2.9  flare at 07:02 UTC.

Region 10689 decayed slowly and quietly.
Region 10690 decayed and lost all spots outside of the single penumbra.
Region 10691 decayed further losing penumbral area and spots. A minor M class flare is possible. Flare: M1.1/1F at 03:22 (associated with a weak proton event and a faint full halo CME) UTC.
Region 10693 developed further adding penumbral area. The region remains fairly simply structured magnetically with no polarity intermixing. A minor M class flare is possible.
Region 10695 was quiet and stable.
New region 10696 emerged quickly in the northeast quadrant on November 1. There is not much separating the opposite polarities and further development will increase the likelihood of C and possibly even minor M class flaring.

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
: No obviously Earth directed CMEs observed.
October 30: Despite lots of flare activity only a single full halo CME was observed in LASCO images. This halo was observed after an M5.9 major flare in region 10691 during the afternoon. This CME could reach Earth on November 2.

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.

Processed SOHO/EIT 284 image at 01:06 UTC on November 2. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to minor storm on November 2 due to a CME impact and unsettled to active on November 3-4 due to effects from coronal hole CH122 and another CME impact.

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 fair to occasionally good. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: WLAM Lewiston ME with a fair signal. On other frequencies propagation was best towards the easternmost parts of North America. There were 3 stations on 610 kHz with WIOD Miami FL dominating (as usual) and CHNC New Carlisle QC the second best signal.

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
10687 2004.10.19 2   N11W92 0030 BXO  
10689 2004.10.21 1 1 N11W71 0020 HAX classification was HSX
at midnight
10690 2004.10.22 4 2 S02W54 0060 CAO classification was HSX
at midnight, area 0030
10691 2004.10.23 8 9 N13W55 0140 DAO  
10692 2004.10.24     S19W80     plage
10693 2004.10.27 50 42 S16E08 0780 FKC  
10694 2004.10.28     N14W29     plage
10695 2004.10.30 3 2 S15E39 0070 DSO  
10696 2004.11.01 6 8 N09E63 0060 DAO  
Total spot count: 74 64
SSN: 144 124

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)
2004.11 135.5 (1) 4.8 (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]