Last major update issued on June 10, 2006 at 04:20 UTC.
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The geomagnetic field was quiet to unsettled on June 9. Solar wind speed ranged between 570 and 719 km/s (all day average 612 km/s - decreasing 9 km/s from the previous day) under the influence of a high speed stream from CH227.
Solar flux measured at 20h UTC on 2.8 GHz was 77.6. The planetary A index
was 10 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 32322222 (planetary), 32322122 (Boulder).
The background x-ray flux is at the class A4 level.
At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10892 decayed significantly losing most of the penumbral area
on the trailing spots. The leader spot took on a symmetrical shape.
Region 10893 decayed and lost all penumbra on the trailing spots.
Spotted regions not numbered by NOAA/SEC:
[S661] This region emerged in the southeast quadrant on June 9. Location at midnight: S06E62
June 7-9: No partly or fully Earth directed CMEs were observed in LASCO imagery.
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
A recurrent coronal hole (CH227) in the northern hemisphere was in an Earth facing position on June 4-6.
Processed SOHO/EIT 284 image at 19:06 UTC on May 26. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on June 10 and mostly quiet on June 11-12.
|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.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation on long distance northeast-southwest paths is fair to good. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Radio Cristal del Uruguay was easily the strongest signla tonight. On other frequencies many stations from Brazil, Uruguay and Argentina were audible, some with relatively strong signals (particularly from 740 Rádio Sociedade and 1190 Radio América).
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|
|10893||2006.06.06||6||6||S02E24||0100||DAO||classification was CSO at midnight,
area 0080, location: S01E22
|Total spot count:||22||25|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2005.12||90.7||41.2||(22.8 predicted, -2.1)|
|2006.01||83.4||15.4||(20.1 predicted, -2.7)|
|2006.02||76.5||4.7||(17.1 predicted, -3.0)|
|2006.03||75.4||10.8||(15.1 predicted, -2.0)|
|2006.04||89.0||30.2||(14.4 predicted, -0.7)|
|2006.05||80.9||22.2||(13.5 predicted, -0.9)|
|2006.06||77.8 (1)||8.1 (2)||(11.4 predicted, -2.1)|
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% lower.
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.