Last major update issued on October 30, 2010 at 04:00 UTC.
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The geomagnetic field was quiet on October 29. Solar wind speed ranged between 348 and 388 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 83.7 (down 1.3 over the last solar rotation). The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.1). Three hour interval K indices: 11001200 (planetary), 21102200 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 3 spotted regions.
Region 11117 decayed with several trailing spots disappearing and the leader spot taking on a symmetrical shape.
Spotted regions not numbered by NOAA/SWPC:
[S830] This region emerged at a high latitude late in the day in the northwest quadrant on October 28. Location at midnight: N36W27
[S831] A new region rotated into view at the northeast limb late on October 29. Location at midnight: N36E79
October 27-29: No obviously Earth directed CMEs were seen in LASCO or STEREO images.
Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
No obvious coronal holes are currently in or near Earth facing positions. An extension of the southern polar coronal hole rotated across the central meridian on October 27-28 but is likely too far to the south to cause a disturbance. Another coronal hole in the northern hemisphere could rotate into an Earth facing position on October 30 but could be too far to the north to become geoeffective.
Image courtesy of SDO (NASA) and the AIA consortium. Annotations are my own. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is very good. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on October 30, there's a chance of unsettled intervals should the CME observed on October 26 reach Earth. On October 31 and November 1 the field is likely to be quiet, however, there is a chance of weak effects (causing unsettled intervals) from the southern polar coronal hole extension that rotated across the central meridian on October 28.
|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) Effects from a CME are likely to be observed at 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.
Compare to the previous day's image
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. 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 SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.
|Active region||Date numbered||Spot count||Location at midnight||Area||Classification||SDO (NASA) / AIA 4500
|Total spot count:||14||20|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
cycle 23 sunspot max.
|2008.07||65.7 (SF minimum)||0.5||2.8 (-0.4)|
|2009.07||68.2||3.2||3.6 (+0.9)||5.49 / 4.55|
|2009.08||67.3||0.0||4.8 (+1.2)||5.70 / 4.89|
|2009.09||70.5||4.3||6.2 (+1.4)||3.88 / 3.61|
|2009.10||72.6||4.8||7.1 (+0.9)||3.66 / 3.56|
|2009.11||73.6||4.1||7.6 (+0.5)||2.45 / 2.63|
|2009.12||76.7||10.8||8.3 (+0.7)||1.41 / 1.92|
|2010.01||81.1||13.2||9.3 (+1.0)||2.93 / 3.07|
|2010.02||84.7||18.8||10.6 (+1.3)||4.15 / 4.61|
|2010.03||83.4||15.4||12.3 (+1.7)||4.58 / 4.65|
|2010.04||75.9||8.0||(13.9 predicted, +1.6)||10.22 / 10.24|
|2010.05||73.8||8.7||(15.2 predicted, +1.3)||9.18 / 8.15|
|2010.06||72.5||13.6||(16.7 predicted, +1.5)||8.17 / 6.85|
|2010.07||79.8||16.1||(18.3 predicted, +1.6)||6.31 / 5.15|
|2010.08||79.2||19.6||(19.5 predicted, +1.2)||8.49 / 7.77|
|2010.09||81.1||25.2||(20.7 predicted, +1.2)||5.33|
|2010.10||81.5 (1)||32.6 (2A) / 34.9 (2B)||(23.1 predicted, +2.4)||(6.31)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official international sunspot number is typically 30-50% lower. 2B) Month average to date.
3) Running average based on the daily SWPC ap indices. Values in red are based on the official NGDC ap indices.
This report has been prepared by Jan Alvestad. It is based on analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.