Solar Terrestrial Activity Report

Last major update issued on November 24, 2003 at 05:10 UTC. Minor update posted at 13:13 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 22, 2003)]

Recent activity

The geomagnetic field was unsettled to minor storm on November 23. Solar wind speed ranged between 466 and 601 km/sec under the influence of a high speed stream from coronal hole CH68.

Solar flux measured at 20h UTC on 2.8 GHz was 178.2. The planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.9).
Three hour interval K indices: 35433344 (planetary), 35433234 (Boulder).

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

At midnight there were 6 spotted regions on the visible disk. Solar flare activity was low. A total of 7 C class events were recorded during the day. Optically uncorrelated events: C1.0 at 00:14 and C1.2 at 12:09 UTC.

Region 10501 decayed further and was quiet.
Region 10506 became spotless. Flare: C1.5 at 16:04 UTC.
Region 10507 developed in the northern part of the main penumbral area while slow decay was observed in the southern part. There is a strong magnetic delta structure within the main penumbra. Major flares are possible. Flare: C1.0 at 01:28 UTC.
Region 10508 developed slowly and quietly. The northernmost spots were split off into region S309 as they appear to be a separate bipolar group. Flares: C1.2 at 17:50 and C3.0 at 23:53 UTC.

Spotted regions not numbered by NOAA/SEC:
[S308] This region rotated into view the southeast limb on November 22. Location at midnight: S11E67.
[S309] This region was split off from region 10508 . Location at midnight: S13E16.
[S310] This region rotated into view at the southeast limb on November 23. Location at midnight: S23E73.Flare: C1.0 at 22:15 UTC.

Comment added at 13:13 UTC on November 24: Regions 10505 and 10506 have reemerged with several spots. A new region has become visible at N03W25 (location at noon). The geomagnetic field has been quiet to unsettled during the first half of the day.

Coronal mass ejections (CMEs)

November 21-23: No partly or fully 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 coronal hole (CH68) in the northern hemisphere was in a geoeffective position on November 20-21. A new and developing coronal hole (CH69) in the southern hemisphere was in a geoeffective position on November 22.

Processed SOHO/EIT 284 image at 01:05 UTC on November 24. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be unsettled to active on November 24-25 due to high speed streams from coronal holes CH68 and CH69, quiet to unsettled is likely on November 26-27.

Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is very poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay with a weak signal. WDHP on 1620 kHz was heard as well].

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
spot
count
STAR
spot
count
Location at midnight Area Classification Comment
10501 2003.11.13 6 4 N03W57 0250 DKI classification was DAO
at midnight, area 0160
10502 2003.11.14     N07W74     plage
10505 2003.11.17 2   S22W21 0010 BXO spotless
10506 2003.11.18 11   S22E05 0020 BXO spotless
10507 2003.11.18 42 47 N09E10 0810 EKC beta-gamma-delta
10508 2003.11.19 47 35 S17E20 0480 EKC beta-gamma
S308 visible on
2003.11.22
  2 S11E67 0060 CSO  
S309 split off on
2003.11.23
  11 S13E16 0040 DAO split off from 10508
S310 visible on
2003.11.23
  3 S23E73 0020 CRO  
Total spot count: 108 102
SSN: 158 162

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)
2003.11 132.3 (1) 61.2 (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]