Last major update issued on June 6, 2011 at 05:25 UTC.
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The geomagnetic field was quiet to major storm on June 5. Solar wind speed ranged between 447 and 638 km/s under the influence of CME effects. Proton flux values increased slowly but remained below event threshold.
Solar flux measured at 20h UTC on 2.8 GHz was 102.9 (decreasing 0.8 over the last solar rotation). The planetary A index was 27 (STAR Ap - based on the mean of three hour interval ap indices: 26.9). Three hour interval K indices: 64443322 (planetary), 64533232 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight UTC the visible solar disk had 10 spotted regions.
Region 11225 decayed slowly and could become spotless today.
Region 11226 decayed in some section. Polarities became mixed again with negative polarity flux emerging just north of the leader spot. C flares are possible.
Region 11227 decayed slowly and quietly.
Region 11228 was quiet and stable.
Region 11229 was quiet and stable.
Region 11230 reemerged with a few spots.
Region 11231 reemerged with tiny spots.
Region 11232 developed mixed polarities as new flux emerged to the south of the largest spot.
New region 11233 was split off from 11227 on June 5 by SWPC, several days after it became obvious that this was an independent region.
Spotted regions not numbered by NOAA/SWPC:
[S1046] reemerged with tiny spots on June 5. Location at midnight: N16E08
June 3-5: No earth directed CMEs were observed.
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 poorly defined weak coronal area or coronal hole (CH453) across the equator between regions S1044 and 11228 was Earth facing on June 4.
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 active on June 6 due to CME effects. On June 7 effects from CH453 could arrive and cause some unsettled intervals. Quiet conditions are likely on June 8.
|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
|12233||2011.06.01||1||2||S18W29||0000||AXX||formerly region S1044|
|Total spot count:||24||54|
|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||107.6 (1)||18.0 (2A) / 107.8 (2B)||(47.4 predicted, +3.7)||(13.25)|
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.