Solar Terrestrial Activity Report

Last major update issued on November 16, 2004 at 03:40 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 November 8, 2004)]
[Archived reports (last update November 12, 2004)]

Recent activity

The geomagnetic field was quiet on November 15. Solar wind speed ranged between 363 and 466 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 105.6. The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.9).
Three hour interval K indices: 00101110 (planetary), 10202220 (Boulder).

The background x-ray flux is at the class B2 level.

At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 3 C class events was recorded during the day.

Region 10700 lost some spots, however, the largest leading and trailing penumbrae increased their area. C flares are likely with a chance of a minor M class flare. Flares: C1.2 at 06:26, C1.5 at 09:25 and C1.3 at 21:36 UTC.
Region 10701 decayed slightly and the single penumbra lost its asymmetrical characteristics.

Spotted regions not numbered by NOAA/SEC:
[S475] A new region emerged fairly quickly east northeast of region 10699 on November 12 and developed slowly on November 13. Slow decay was observed on November 14 and 15. SEC has this as region 10699 as they previously failed to separate these two regions. The original region 10699 is now spotless.

Coronal mass ejections (CMEs)

November 13-15: 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

Recurrent coronal hole CH127 in the northern hemisphere will likely rotate into a geoeffective position on November 15-17.

Processed SOHO/EIT 284 image at 19:06 UTC on November 15. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 16-17. A high speed stream from coronal hole CH127 will likely begin to influence the geomagnetic field on November 18 and cause unsettled to active conditions until November 20 with a chance of minor storm intervals on Nov. 18 and 19.

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 useless. Propagation along long distance north-south paths is very poor, however, some slight improvement in conditions were noted compared to the situation 24h earlier. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: none, only a carrier detected. Two frequencies had audio from Brazilian stations, 740 and 1440 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
spot
count
STAR
spot
count
Location at midnight Area Classification Comment
10699 2004.11.09 6   S13W10 0050 EAO spotless
location: S15W16
SEC has failed to
separate regions 10699
and S475
10700 2004.11.11 18 16 N04W53 0200 DAI  
10701 2004.11.11 3 2 S15E17 0070 CSO classification was HSX
at midnight
S475 emerged on
2004.11.12
  4 S14W07 0040 DAO  
S477 emerged on
2004.11.14
    S03E36     plage
Total spot count: 27 22
SSN: 57 52

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)
2004.11 119.4 (1) 44.2 (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.


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