Last major update issued on June 10, 2011 at 04:05 UTC.
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The geomagnetic field was quiet to unsettled on June 9. Solar wind speed ranged between 336 and 550 km/s. A disturbance arrived at SOHO near 21h UTC with solar wind speed increasing from below 400 to near 550 km/s. The source of this disturbance is uncertain.
Solar flux measured at 20h UTC on 2.8 GHz was 87.5 (decreasing 4.0 over the last solar rotation). The planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.0). Three hour interval K indices: 33222233 (planetary), 23322234 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 6 spotted regions.
Region 11227 was quiet and stable and will rotate out of view at the
southwest limb today.
Region 11228 was quiet and will rotate over the northwest limb today.
Region 11232 decayed slowly and quietly.
New region 11234 rotated into view at the southeast limb on June 8 and was numbered the next day by NOAA/SWPC. Flare: C1.0 at 10:28 UTC
Spotted regions not numbered by NOAA/SWPC:
[S1046] reemerged with tiny spots on June 5. Location at midnight: N18W43
[S1055] emerged in the southern hemipshere near the central meridian on June 9. Location at midnight: S35W05
Region 11226 produced 2 flares while at the southwest limb: C1.8 at 03:21 and C4.1 at 03:45 UTC.
June 8-9: No obviously earth directed CMEs were observed.
June 7: A wide, full halo CME was observed after the M2.5 event in region 11226.
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 was in an Earth facing position early 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 poor. Propagation on long distance northeast-southwest paths is fair.
The geomagnetic field is expected to be quiet to minor storm on June 10 due to CME effects and quiet to unsettled on June 11. On June 12 there's a chance of a few unsettled intervals due to effects from CH454. On June 13-14 a high speed stream from CH455 could cause some unsettled and active intervals.
|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
|2||7||S16E59||0010||BXO||BXO||formerly region S1053|
|Total spot count:||6||18|
|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||101.4 (1)||25.2 (2A) / 83.9 (2B)||(47.4 predicted, +3.7)||(11.89)|
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.