Last major update issued on June 28, 2010 at 04:10 UTC.
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The geomagnetic field was quiet to active on June 27. Solar wind speed ranged between 450 and 567 km/s under the influene of a high speed stream from CH410.
Solar flux measured at 20h UTC on 2.8 GHz was 72.9. The planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 13.3). Three hour interval K indices: 34322233 (planetary), 23432222 (Boulder).
The background x-ray flux is at the class A5 level.
At midnight there was 1 spotted regions on the visible solar disk.
New region 11084 rotated into view at the southeast limb early on June 26 and was numbered the next day by NOAA/SWPC.
June 25-27: 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
A recurrent trans equatorial coronal hole (CH410) was in an Earth facing position on June 22-24. CH410 is an extension of the northern polar coronal hole, an extension which has expanded greatly over the last solar rotation. Further expansion could cause a disturbance lasting more than a week. A small, new coronal hole (CH411) in the southern hemisphere will rotate into an Earth facing position on June 28.
Image Courtesy of SDO (NASA) and the AIA consortium. 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 poor. Propagation on long distance northeast-southwest paths is fair.
The geomagnetic field is expected to be quiet to unsettled on June 28-30 due to coronal hole stream effects.
|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
|11084||2010.06.27||1||1||S19E59||0090||HSX||HSX||formerly region S784
|Total spot count:||1||1|
|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||6.1 (+1.3)||3.88 / 3.61|
|2009.10||72.6||4.8||7.0 (+0.9)||3.66 / 3.56|
|2009.11||73.6||4.1||7.6 (+0.6)||2.45 / 2.63|
|2009.12||76.7||10.8||(8.2 predicted, +0.6)||1.41 / 1.92|
|2010.01||81.1||13.1||(9.2 predicted, +1.0)||2.93 / 3.07|
|2010.02||84.7||18.6||(10.7 predicted, +1.5)||4.15 / 4.61|
|2010.03||83.4||15.4||(12.5 predicted, +1.8)||4.58 / 4.65|
|2010.04||75.9||7.9||(14.1 predicted, +1.6)||10.22 / 10.24|
|2010.05||73.8||8.8||(15.4 predicted, +1.3)||9.18 / 8.15|
|2010.06||72.3 (1)||16.4 (2)||(16.9 predicted, +1.5)||(7.70)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) 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.
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 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.