Last major update issued on June 24, 2011 at 04:35 UTC.
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Annotated geomagnetic activity charts - Carrington rotation
2109 [April-May
2011] - 2110 [May-June
2011]
[Solar polar fields vs solar cycles - updated
June 11, 2011]
The geomagnetic field was quiet to active on June 23. Solar wind speed ranged between 560 and 692 km/s. The dominant solar wind source was a high speed stream from CH457. A solar wind shock was observed at SOHO at 02:18 UTC, the same shock front was recorded as a sudden impulse at Boulder 40 minutes later. This was likely the arrival of the CME observed on June 21. In the presence of a high speed coronal hole stream a CME often breaks down and merge with the other disturbance. In this case the shock front was strong enough to retain some of its CME characteristics.
Solar flux measured at 20h UTC on 2.8 GHz was 96.3 (increasing 6.4 over the last solar rotation). The planetary A index was 18 (STAR Ap - based on the mean of three hour interval ap indices: 17.8). Three hour interval K indices: 44233333 (planetary), 44333233 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 9 spotted regions.
Region 11236 was quiet and stable.
Region 11237 decayed and could soon become spotless.
Region 11239 decayed slowly and quietly.
Region 11240 developed early in the day with slow decay observed later as
the opposite polarity areas drifted apart.
Spotted regions not numbered by NOAA/SWPC:
[S1077] emerged in the northeast quadrant on June 22 and developed
slowly on June 23. Location at midnight: N18E08
[S1079] emerged in the northeast quadrant on June 23. Location at midnight:
N08E50
[S1080] emerged in the southwest quadrant on June 23. Location at
midnight: S24W21
[S1081] emerged in the trailing polarity area of region 11236 on June 23.
Location at midnight: N18W42
[S1082] emerged in the northwest quadrant on June 23. Location at
midnight: N23W08
June 22-23: No obviously earth directed CMEs were observed.
June 21: A halo CME was observed after a C7 LDE in region 11236. Although
most of the core of the CME was observed over the northern limbs, Earth appears
to be in the path of the southern part of the core. The CME likely reached
Earth on June 23.
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 coronal hole (CH457) in the southern hemisphere was Earth facing on June 19-20. A coronal hole (CH459) in the northern hemisphere was Earth facing on June 23. A recurrent coronal hole (CH460) in the northern hemisphere will likely rotate into an Earth facing position on June 27.
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 to good.
The geomagnetic field is expected to be unsettled to active on June 24 due to combined CME and coronal hole effects. Quiet to unsettled is likely on June 25. Some unsettled and active intervals are possible on June 26-27 due to effects from CH459.
| 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.
(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 detected |
Spot count | Location at midnight | Area | Classification | SDO / HMI 4K continuum image with polarity overlay |
Comment | |||
|---|---|---|---|---|---|---|---|---|---|---|
| SWPC | STAR SDO | SWPC | STAR | Current | Previous | |||||
| 11236 | 2011.06.13 2011.06.14 |
4 | 12 | N16W46 | 0150 | CSO | CHO |
 |
 |
area: 0260 location: N16W51 |
| 11237 | 2011.06.16 2011.06.17 |
1 | S18W15 | 0000 | AXX |
 |
 |
|||
| 11239 | 2011.06.17 2011.06.20 |
3 | 6 | N16W27 | 0010 | BXO | BXO |
 |
 |
area: 0000 |
| 11238 | 2011.06.18 2011.06.19 |
S17W45 | plage | |||||||
| S1072 | 2011.06.18 | S18W55 | plage | |||||||
| S1073 | 2011.06.19 | S05W09 | plage | |||||||
| S1074 | 2011.06.19 | S16W62 | plage | |||||||
| 11240 | 2011.06.20 | 10 | 10 | S18E02 | 0050 | DRO | CRO |
 |
 |
location: S20E04 |
| S1075 | 2011.06.20 | N36W24 | plage | |||||||
| S1076 | 2011.06.21 | S09E10 | plage |
|||||||
| S1077 | 2011.06.22 | 18 | N18E08 | 0050 | DRI |
 |
 |
|||
| S1078 | 2011.06.22 | S47W25 |
 |
reversed polarities plage |
||||||
| S1079 | 2011.06.23 | 2 | N08E50 | 0000 | BXO |
 |
||||
| S1080 | 2011.06.23 | 2 | S24W21 | 0000 | BXO |
 |
||||
| S1081 | 2011.06.23 | 5 | N18W42 | 0010 | CRO |
 |
||||
| S1082 | 2011.06.23 | 1 | N23W08 | 0000 | AXX |
 |
||||
| Total spot count: | 17 | 57 | ||||||||
| Sunspot number: | 47 | 147 | ||||||||
| Month | Average measured solar flux | International sunspot number (SIDC) | Smoothed sunspot number | Average ap (3) |
|---|---|---|---|---|
| 2008.07 | 65.7 (SF minimum) | 0.5 | 2.8 (-0.4) | |
| 2008.12 | 69.2 | 0.8 | 1.7 (-) sunspot minimum |
3.25 |
| 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 | 97.5 (1) | 46.2 (2A) / 60.3 (2B) | (47.4 predicted, +3.7) | (9.90) |
1) Running average based on the daily 20:00 UTC observed solar flux value at
2800 MHz.
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.
