Last major update issued on October 16, 2011 at 17:45 UTC.
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The geomagnetic field was quiet to unsettled on October 15. Solar wind speed ranged between 369 and 455 km/s under the influence of a high speed stream associated with CH479.
Solar flux measured at 20h UTC on 2.8 GHz was 137.7 (decreasing 12.4 over the last solar rotation). The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.1). Three hour interval K indices: 32012322 (planetary), 32102211 (Boulder).
The background x-ray flux is at the class B6 level.
At midnight UTC the visible solar disk had 14 spotted regions (in 2K resolution SDO images).
Region 11312 [N23W67] was quiet and decayed.
Region 11313 [S13W68] decayed slowly and quietly.
Region 11314 [N28W03] was mostly quiet. Several small spots
emerged to the northwest of the large penumbra. Flare:
C1.6 at 12:39 UTC
Region 11316 [S12E04] decayed slowly and was mostly quiet.
Flare: C1.5 at 18:13 UTC
Region 11317 [S26E30] was quiet and stable.
Region 11318 [N21W48] decayed further and could soon become spotless
Region 11319 [N11E03] added spots and increased penumbral area. An M
class flare is possible. Flares: C1.3 at
01:12, C2.0 at 13:25, C5.0 at 14:13, C2.3 at 16:21 UTC
Region 11320 [S21W63] lost several spots and was quiet.
New region 11321 [N11E33] emerged in the northeast quadrant on October 14
and was numbered the next day by SWPC. The region decayed slowly on October 15.
New region 11322 [S27W50] emerged in the southwest quadrant on October
15.
Spotted regions not reported by NOAA/SWPC:
[S1268] reemerged with several tiny spots on October 14. Location at midnight:
N21W07
[S1275] emerged in the southeast quadrant on October 15. Location at midnight:
S14E52
[S1276] emerged in the southwest quadrant on October 15. Location at midnight:
S13W53
[S1277] emerged in the southwest quadrant on October 15. Location at midnight:
S06W15
October 13-15: No obviously Earth directed CMEs observed.
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 trans equatorial coronal hole (CH479) was in an Earth facing position on October 12-13.
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 to fair. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to unsettled on October 16 and quiet on October 17-18.
| 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 | |||||
| 11312 | 2011.10.03 2011.10.04 |
1 | 1 | N23W68 | 0180 | HHX | HHX |
 |
 |
area: 0320 |
| 11313 | 2011.10.04 2011.10.05 |
5 | 2 | S16W64 | 0070 | DSO | HAX |
 |
 |
area: 0030 |
| S1257 | 2011.10.07 | N11W32 | plage | |||||||
| 11314 | 2011.10.08 2011.10.09 |
4 | 9 | N28W04 | 0330 | CHO | CHO |
 |
 |
area: 0400 |
| 11315 | 2011.10.09 2011.10.10 |
N20W57 |
 |
plage |
||||||
| 11317 | 2011.10.10 2011.10.11 |
1 | 2 | S26E15 | 0080 | HSX | CSO |
 |
 |
|
| 11316 | 2011.10.10 2011.10.11 |
11 | 18 | S12E03 | 0340 | DHI | DHO |
 |
 |
area: 0450 |
| 11319 | 2011.10.10 2011.10.12 |
30 | 58 | N11E01 | 0240 | EAI | EAI |
 |
 |
beta-gamma area: 0400 |
| S1268 | 2011.10.10 | 3 | N21W07 | 0000 | AXX |
 |
 |
|||
| 11318 | 2011.10.11 2011.10.12 |
4 | 3 | N25W46 | 0020 | CSO | AXX |
 |
 |
area: 0010 location: N21W48 |
| S1271 | 2011.10.12 | N07W14 | plage | |||||||
| 11320 | 2011.10.13 | 4 | 4 | S21W65 | 0010 | AXX | DRO |
 |
 |
|
| 11321 | 2011.10.14 2011.10.15 |
2 | 3 | N13E52 | 0010 | BXO | BXO |
 |
 |
|
| 11322 | 2011.10.15 | 4 | 4 | S27W51 | 0010 | BXO | DRO |
 |
||
| S1273 | 2011.10.14 | N12E25 |
 |
plage | ||||||
| S1275 | 2011.10.15 | 2 | S14E52 | 0020 | CRO |
 |
||||
| S1276 | 2011.10.15 | 1 | S13W53 | 0000 | AXX |
 |
||||
| S1277 | 2011.10.15 | 1 | S06W15 | 0000 | AXX |
 |
||||
| Total spot count: | 66 | 111 | ||||||||
| Sunspot number: | 166 | 251 | (total spot count + 10 * number of spotted regions) | |||||||
| Classification adjusted SN: | 116 | 165 | (Sum of total spot count + classification adjustment for each AR. Classification adjustment: X=0, R=3, A/S=5, H/K=10) | |||||||
| Relative sunspot number (Wolf number): | 100 | 83 | k * (sunspot number). k = 0.6 for SWPC. k = 0.33 for STAR SDO | |||||||
| 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 |
| 2010.07 | 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 | 31.0 (+2.2) | 4.32 / 5.51 |
| 2011.02 | 94.6 | 29.4 | 33.4 (+2.4) | 5.41 / 6.44 |
| 2011.03 | 115.0 | 56.2 | 36.9 (+3.5) | 7.79 / 8.18 |
| 2011.04 | 112.6 | 54.4 | (41.1 predicted, +4.2) | 9.71 / 8.83 |
| 2011.05 | 95.8 | 41.6 | (45.2 predicted, +4.1) | 9.18 / 8.94 |
| 2011.06 | 95.8 | 37.0 | (49.2 predicted, +4.0) | 8.96 |
| 2011.07 | 94.2 | 43.9 | (53.1 predicted, +3.9) | 9.14 |
| 2011.08 | 101.7 | 50.6 | (57.2 predicted, +4.1) | 8.16 |
| 2011.09 | 133.8 | 78.0 | (60.3 predicted, +3.1) | 12.80 |
| 2011.10 | 129.4 (1) | 53.3 (2A) / 110.1 (2B) | (61.8 predicted, +1.5) | (7.62) |
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.
