Last major update issued on June 22, 2011 at 04:10 UTC.
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Annotated geomagnetic activity charts - Carrington rotation
2109 [April-May
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[Solar polar fields vs solar cycles - updated
June 11, 2011]
The geomagnetic field was quiet to unsettled on June 21. Solar wind speed ranged between 370 and 502 km/s influenced by effects from CH458.
Solar flux measured at 20h UTC on 2.8 GHz was 95.1 (increasing 14.8 over the last solar rotation). The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.8). Three hour interval K indices: 23213322 (planetary), 22222322 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 5 spotted regions.
Region 11236 decayed further as the trailing spots lost all penumbra.
Flare: long duration C7.7 event peaking at
03:25 UTC. This event was associated with a symmetrical halo CME.
Region 11237 was quiet and stable.
Region 11239 was quiet and stable.
Region 11240 was quiet and stable.
Spotted regions not numbered by NOAA/SWPC:
[S1076] emerged in the southeast quadrant on June 21. Location at midnight:
S09E36
June 19: A partial halo CME was observed by LASCO beginning at 16:36 UTC
following an event in region 11237. A flank impact is possible from this CME on
June 22 or 23.
June 20: 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 will likely reach
Earth on June 23 or 24 and could cause a major geomagnetic disturbance.
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 will be Earth facing on June 23.
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 unsettled on June 22. Late on June 22 or early on June 23 a high speed stream from CH457 will likely reach Earth and cause unsettled to minor storm conditions. The CME observed early on June 21 could reach Earth on June 23 and cause unsettled to major storm conditions lasting 24-36 hours.
| 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 |
18 | 14 | N17W21 | 0190 | ESI | CHO |
 |
 |
area: 0280 |
| 11237 | 2011.06.16 2011.06.17 |
4 | S18E13 | 0000 | BXO |
 |
 |
location: S17E15 | ||
| 11239 | 2011.06.17 2011.06.20 |
6 | 11 | N18W00 | 0010 | BXO | BXO |
 |
 |
location: N16W01 |
| 11238 | 2011.06.18 2011.06.19 |
S17W17 | plage | |||||||
| S1072 | 2011.06.18 | S18W29 | plage | |||||||
| S1073 | 2011.06.19 | S05E17 | plage | |||||||
| S1074 | 2011.06.19 | S16W36 | plage | |||||||
| 11240 | 2011.06.20 | 3 | 8 | S17E27 | 0010 | BXO | BXO |
 |
location: S20E29 | |
| S1075 | 2011.06.20 | N36E91 |
 |
plage | ||||||
| S1076 | 2011.06.21 | 1 | S09E36 | 0000 | AXX |
 |
reversed polarities | |||
| Total spot count: | 27 | 38 | ||||||||
| Sunspot number: | 57 | 88 | ||||||||
| 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 | 97.8 (1) | 43.2 (2A) / 61.7 (2B) | (47.4 predicted, +3.7) | (9.44) |
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.
