Last major update issued on July 9, 2011 at 05:10 UTC.
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The geomagnetic field was quiet to unsettled on July 8. Solar wind speed ranged between 322 and 372 km/s. The leading part of a disturbance associated with CH463 was observed at ACE after approximately 20h UTC.
Solar flux measured at 20h UTC on 2.8 GHz was 85.8 (increasing 1.1 over the last solar rotation). The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 21321223 (planetary), 11331213 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 6 spotted regions.
Region 11243 decayed further and was mostly quiet.
Region 11245 matured and decayed.
New region 11246 was first observed with spots on July 2, then became spotless and reemerged with spots on July 7. The region was numbered by SWPC the next day.
New region 11247 rotated into view at the southeast limb on July 3 and was numbered by NOAA/SWPC 5 days later. The region developed quickly early on July 8, then relaxed and seems to be decaying. Flares: C3.0 at 09:47, C2.8/1F at 11:51, C3.1/1N at 13:31 and C2.3 at 15:03 UTC.
New region 11248 rotated into view at the northeast limb on July 6 and was numbered by SWPC 2 days later. The region decayed on July 8 and could soon become spotless.
Spotted regions not numbered by NOAA/SWPC:
[S1104] emerged in the southeastern quadrant on July 7. Location at midnight: S18E41
July 6-8: No obviously earth directed CMEs were observed.
July 9: A long duration B4 event peaking near 01:00 UTC was associated with a filament eruption to the east of region 11247. A CME was observed and there's a fair chance this CME will reach Earth on July 12.
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 coronal hole (CH463) in the northern hemisphere was Earth facing on July 5-6. A recurrent coronal hole (CH464) in the southern hemisphere was Earth facing on July 7-8. A trans equatorial coronal hole (CH465) will likely become Earth facing on July 10.
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 active on July 9-11 due to high speed streams from CH463 and CH464. A weak CME could reach Earth on July 12 and cause a few unsettled and active intervals. A disturbance associated with CH465 may cause quiet to active conditions on July 13-14.
|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
|3||2||N14W47||0000||BXO||BXO||formerly region S1095|
|7||14||S18E11||0020||DAI||CAO||formerly region S1096
|1||1||N20E53||0010||AXX||AXX||formerly region S1103
|Total spot count:||15||28|
|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)|
|2010.04||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||28.8 (+2.3)||3.41 / 4.35|
|2011.01||83.6||19.1||(30.6 predicted, +1.8)||4.32 / 5.51|
|2011.02||94.6||29.4||(32.6 predicted, +2.0)||5.41 / 6.44|
|2011.03||115.0||56.2||(35.2 predicted, +2.6)||7.79 / 8.18|
|2011.04||112.6||54.4||(38.1 predicted, +2.9)||9.71 / 8.83|
|2011.05||95.8||41.6||(41.4 predicted, +3.3)||9.18 / 8.94|
|2011.06||95.8||37.0||(45.2 predicted, +3.8)||8.96|
|2011.07||85.6 (1)||11.7 (2A) / 45.5(2B)||(49.4 predicted, +4.1)||(9.39)|
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.