Last major update issued on September 28, 2014 at 05:40 UTC.
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[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last
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September 6, 2014)]
[New: Noon SDO count 1K 4K (large file)]
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[Solar polar fields vs solar cycles - updated
September 6, 2014]
[Presentations:
3rd
SSN Workshop, Tucson, 2013 (pdf)
/
4th SSN Workshop, Locarno, 2014]
The geomagnetic field was quiet to active on September 27. Solar wind speed at SOHO ranged between 385 and 465 km/s under the decreasing influence of a high speed stream from CH636.
Solar flux at 20h UTC on 2.8 GHz was 181 (increasing 56.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 138.0. The Potsdam WDC planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 13.0). Three hour interval K indices: 44322221 (planetary), 44432221 (Boulder).
The background x-ray flux is at the class C1 level.
At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 376) and 14 active regions using 1K resolution (SN: 259) SDO images on the visible solar disk.
Region 12171 [S11W39] decayed slowly and quietly.
Region 12172 [S11W14] decayed slowly and produced a few low level C
flares. A major flare is still possible.
Region 12173 [S17W25] developed further with the trailing polarity area
interacting with the leading polarity area of AR 12172. A major M5.1 flare was
recorded in the trailing polarity area at 02:58 UTC on September 28. This CME
may have been associated with a CME, however, relevant imagery is not available
as this is written.
Region 12175 [N14W38] matured somewhat and has a moderately strong
magnetic delta structure within a central penumbra. A major flare is possible.
Region 12176 [N07E18] was quiet and stable.
Region 12177 [N12E55] is a compact region with minor M class flare
potential.
New region 12178 [S01E74] rotated into view and could be capable of
producing a minor M class flare.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3848 [S14E39] was quiet and stable.
S3852 [S08W36] decayed slowly and quietly.
New region S3857 [S11E83] rotated into view.
New region S3858 [N03E83] rotated into view.
New region S3859 [N11E39] was observed with penumbra spots.
New region S3860 [S00W05] was observed with a penumbra spot.
New region S3861 [N12E63] was split off from AR 12177.
C2+ flares (GOES):
| Magnitude | Peak time (UTC) | Location | AR | Comment |
| C2.2 | 00:15 | S15W10 | 12173 | |
| C2.4 | 06:50 | S18W15 | 12173 | |
| M1.0 | 08:37 | E limb | 12178? | |
| C2.3 | 15:51 | 12172 | ||
| C2.7 | 19:51 | 12172 |
September 25-27: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
[Coronal hole history (since October
2002)]
[Compare today's report to the situation one solar rotation ago:
28 days ago
27 days ago
26 days ago]
No obvious coronal holes are currently in or near Earth facing positions.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over 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 September 28 due to coronal hole effects and quiet on September 29-30.
| Coronal holes (1) | Coronal mass ejection (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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.
(Click on image for 2K resolution) Compare to the previous day's image. 0.5K image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue 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 magnetic polarity overlay |
Comment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SWPC | Magnetic (SDO) |
SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 12169 | 2014.09.16 2014.09.17 |
N07W71 |
 |
plage |
|||||||
| 12170 | 2014.09.16 2014.09.17 |
N12W66 |
plage |
||||||||
| 12171 | 2014.09.18 2014.09.19 |
9 | 18 | 10 | S10W41 | 0090 | ESO | FAO |
 |
 |
location: S11W39 |
| 12173 | 2014.09.19 2014.09.20 |
23 | 59 | 28 | S17W26 | 0130 | DAC | DAC |
 |
 |
beta-gamma area: 0300 |
| 12172 | 2014.09.20 | 40 | 84 | 39 | S11W17 | 0460 | EKC | EKC |
 |
 |
beta-gamma area: 0820 location: S11W14 |
| 12175 | 2014.09.21 2014.09.25 |
19 | 38 | 18 | N15W38 | 0360 | DKC | DAC |
 |
 |
beta-gamma-delta area: 0620 |
| S3836 | 2014.09.22 | S11W57 | plage | ||||||||
| S3837 | 2014.09.22 | N15W52 | plage | ||||||||
| 12176 | 2014.09.22 2014.09.25 |
5 | 1 | N07E13 | 0008 | AXX |
 |
 |
location: N07E18 | ||
| S3842 | 2014.09.23 | S20W55 | plage | ||||||||
| S3844 | 2014.09.24 | N17W41 | plage | ||||||||
| S3845 | 2014.09.24 | S24W58 | plage | ||||||||
| 12177 | 2014.09.25 | 7 | 11 | 9 | N11E56 | 0110 | EAI | DAC |
 |
 |
location: N12E55 |
| S3847 | 2014.09.25 | N01W48 | plage | ||||||||
| S3848 | 2014.09.25 | 5 | 2 | S14E39 | 0012 | BXO |
 |
 |
|||
| S3850 | 2014.09.26 | S16E12 |
 |
plage | |||||||
| S3851 | 2014.09.26 | N10W16 |
 |
plage | |||||||
| S3852 | 2014.09.26 | 1 | 1 | S08W36 | 0003 | AXX |
 |
 |
|||
| S3853 | 2014.09.26 | N29W32 |
 |
plage | |||||||
| S3854 | 2014.09.26 | N23W35 |
 |
plage | |||||||
| 12178 | 2014.09.27 | 1 | 5 | 3 | S01E75 | 0030 | HSX | CAO |
 |
area: 0150 | |
| S3857 | 2014.09.27 | 1 | 1 | S11E83 | 0110 | HSX |
 |
||||
| S3858 | 2014.09.27 | 1 | 1 | N03E83 | 0010 | HRX |
 |
||||
| S3859 | 2014.09.27 | 4 | 2 | N11E39 | 0012 | BXO |
 |
||||
| S3860 | 2014.09.27 | 1 | 1 | S00W05 | 0004 | AXX |
 |
||||
| S3861 | 2014.09.27 | 3 | 3 | N12E63 | 0017 | DRO |
 |
||||
| Total spot count: | 99 | 236 | 119 | ||||||||
| Sunspot number: | 159 | 376 | 259 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 139 | 282 | 165 | (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10) | |||||||
| Relative sunspot number (Wolf number): | 95 | 132 | 142 | k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number) | |||||||
| Month | Average solar flux | International sunspot number (WDC-SILSO) |
Smoothed sunspot number | Average ap (3) |
|
|---|---|---|---|---|---|
| Measured | 1 AU | ||||
| 2013.05 | 131.4 | 134.3 | 78.7 | 59.9 (+2.0) | 9.73 |
| 2013.06 | 110.1 | 113.7 | 52.5 | 62.6 (+2.7) | 12.60 |
| 2013.07 | 115.5 | 119.3 | 57.0 | 65.5 (+2.9) | 9.47 |
| 2013.08 | 114.6 | 118.3 | 66.0 | 69.0 (+3.5) | 8.27 |
| 2013.09 | 102.6 | 103.7 | 36.9 | 73.1 (+4.1) | 5.23 |
| 2013.10 | 132.1 | 131.2 | 85.6 | 75.0 (+1.9) | 7.71 |
| 2013.11 | 148.3 | 145.1 | 77.6 | 75.4 (+0.4) | 5.68 |
| 2013.12 | 147.7 | 143.1 | 90.3 | 76.0 (+0.6) | 4.68 |
| 2014.01 | 157.4 | 152.4 | 81.8 | 77.3 (+1.3) | 5.44 |
| 2014.02 | 170.3 (cycle peak) |
166.3 | 102.3 (cycle peak) | 78.4 (+1.1) | 10.70 |
| 2014.03 | 149.9 | 148.5 | 91.9 | (80.3 projected, +1.9) | 4.88 |
| 2014.04 | 143.9 | 144.8 | 84.7 | (81.0 projected, +0.7) | 7.88 |
| 2014.05 | 129.7 | 132.9 | 75.2 | (79.2 projected, -1.8) | 5.75 |
| 2014.06 | 122.0 | 125.8 | 71.0 | (76.6 projected, -2.6) | 6.72 |
| 2014.07 | 137.4 | 141.8 | 72.5 | (73.6 projected, -3.0) | 4.50 |
| 2014.08 | 124.7 | 127.9 | 74.7 | (70.1 projected, -3.5) | 7.71 |
| 2014.09 | 143.3 (1) | 112.4 (2A) / 124.9 (2B) / 90.7 (2C) | (65.9 projected, -4.2) | (9.7) | |
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 WDC-SILSO international sunspot number is typically 30-50% lower. 2B)
Boulder SN current month
average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices.
Values in red are based on the definitive
international
GFZ Potsdam
WDC
ap indices.
This report has been prepared by Jan Alvestad. It is based on the 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.
