Last major update issued on October 29, 2004 at 04:30 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 18, 2004)]
The geomagnetic field was inactive to very quiet on October 28. Solar wind speed ranged between 287 and 367 km/sec.
Solar flux measured at 17h UTC on 2.8 GHz was 133.4. 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: 11001111 (planetary), 22002211 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight there were 8 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 10684 decayed slowly and is rotating out of view at the southwest limb.
October 26 and 28: No obviously Earth directed CMEs observed.
October 27: A faint, slow, full halo CME was observed in LASCO C3 images beginning at 13:42 UTC. The origin of this CME may have been in region 10691 around 09h UTC. This was the only significant frontside activity that can be related to the CME. If the CME was frontsided it could reach Earth on October 31.
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 (CH121) in the southern hemisphere was in a geoeffective position on October 25-26.
Processed SOHO/EIT 284 image at 19:06 UTC on October 28. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on October 29-30, possibly with isolated active intervals due to effects from coronal hole CH121. Unsettled to active is possible on October 31 if the CME observed on October 27 arrived.
|Coronal holes (1)||Coronal mass ejections (2)||M and X class flares (3)|
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 good to very good. Propagation along long distance north-south paths is very 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 eastern part of North America. Again daytime signals could be heard from a number of US stations. WFIF Milford CT on 1500 kHz and WIZZ Greenfield MA on 1520 kHz could be heard with good signals, other examples were WVNE Leicester MA on 760 and WNYC New York on 820 kHz. KBRW Barrow, Alaska on 680 kHz was heard during the afternoon of October 28 at 16:15 UTC.
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|
area was 0050
area was 0120
area was 0050
classification was HAX
at midnight, area 0060
area was 0100
classification was CAO
classification was EKO
at midnight, area 0550
formerly region S466
classification was BXO
at midnight, area 0010
|Total spot count:||70||65|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2004.04||101.2||39.3||(44.6 predicted, -2.5)|
|2004.05||99.8||41.5||(40.9 predicted, -3.7)|
|2004.06||97.4||43.2||(38.0 predicted, -2.9)|
|2004.07||119.1||51.0||(36.2 predicted, -1.8)|
|2004.08||109.6||40.9||(34.6 predicted, -1.6)|
|2004.09||103.1||27.7||(32.8 predicted, -1.6)|
|2004.10||102.8 (1)||63.5 (2)||(30.5 predicted, -2.3)|
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.