Last major update issued on June 8, 2011 at 05:25 UTC. Coronal hole update posted at 16:30 UTC.
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The geomagnetic field was quiet to active on June 7. Solar wind speed ranged between 355 and 511 km/s. A disturbance (possibly related to CH453) was observed arriving at ACE near 16h UTC and caused unsettled to active conditions for the remainder of the day and minor storming early on June 8.
Solar flux measured at 20h UTC on 2.8 GHz was 96.4 (increasing 2.3 over the last solar rotation). The planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 8.6). Three hour interval K indices: 10111243 (planetary), 21111234 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 9 spotted regions.
Region 11226 produced a minor M2.5/2N proton event peaking at 06:41
UTC. This event was associated with moderate type II and IV radio sweeps and a
full halo CME.
Region 11227 decayed slowly and quietly.
Region 11228 decayed slowly and quietly.
Region 11230 was quiet and stable.
Region 11231 reemerged with a single spot.
Region 11232 decayed and was quiet.
Spotted regions not numbered by NOAA/SWPC:
[S1046] reemerged with tiny spots on June 5. Location at midnight: N17W16
[S1049] emerged in the southeast quadrant on June 6. Location at midnight: S17E07
[S1052] emerged in the northeast quadrant on June 7. Location at midnight: N11E58
June 5-6: No obviously earth directed CMEs were observed.
June 7: A wide, full halo CME was observed after the M2.5 event in region 11226. The CME could reach Earth sometime during the latter half of June 9.
Coronal hole history (since late October
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A small coronal hole (CH454) in the northern hemisphere will rotate into an Earth facing position on June 9. An elongated coronal hole (CH455) in the southern hemisphere will likely become Earth facing on June 10-11.
The above coronal hole map is based on a new method where coronal holes are detected automatically. The method may need some fine tuning, however, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using the new method, the extent and intensity of both holes are consistent with other data sources.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is very poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to minor storm on June 8 due to effects from CH453. Quiet to major storm is likely on June 9-10 due to CME 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
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.
(Click on image for higher resolution image) Compare to the previous day's image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue (blue-green) is positive.
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 / HMI 4K continuum
image with polarity overlay
|Total spot count:||18||31|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
|2008.07||65.7 (SF minimum)||0.5||2.8 (-0.4)|
|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||14.0 (+1.7)||10.22 / 10.24|
|2010.05||73.8||8.7||15.5 (+1.5)||9.18 / 8.15|
|2010.06||72.5||13.6||16.4 (+0.9)||8.17 / 6.85|
|2010.07||79.8||16.1||16.7 (+0.3)||6.31 / 5.15|
|2010.08||79.2||19.6||17.4 (+0.7)||8.49 / 7.77|
|2010.09||81.1||25.2||19.6 (+2.2)||5.33 / 5.45|
|2010.10||81.6||23.5||23.2 (+3.6)||6.07 / 6.27|
|2010.11||82.5||21.5||26.5 (+3.3)||4.80 / 5.50|
|2010.12||84.2||14.4||(29.4 predicted, +2.9)||3.41 / 4.35|
|2011.01||83.6||19.1||(32.6 predicted, +3.2)||4.32 / 5.51|
|2011.02||94.6||29.4||(35.2 predicted, +2.6)||5.41 / 6.44|
|2011.03||115.0||56.2||(37.5 predicted, +2.3)||7.79|
|2011.04||112.6||54.4||(40.4 predicted, +2.9)||9.71|
|2011.05||95.8||41.6||(43.7 predicted, +3.3)||9.18|
|2011.06||104.9 (1)||22.1 (2A) / 94.9 (2B)||(47.4 predicted, +3.7)||(11.73)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official SIDC international sunspot number is typically 30-50% lower. 2B) Month average to date.
3) Running average based on the preliminary 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.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.