Last major update issued on May 6, 2014 at 04:20 UTC.
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[Solar cycles 23-24 (last update May 1, 2014)] [Cycle
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[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last
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[Historical solar and geomagnetic data charts 1954-2006
(last update April 5, 2007)]
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[Solar polar fields vs solar cycles - updated
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[Presentation
3rd
SSN Workshop, Tucson, 2013 (pdf)]
The geomagnetic field was quiet to unsettled on May 5. Solar wind speed at SOHO ranged between 344 and 497 km/s, still under the influence of weak CME effects.
Solar flux at 20h UTC on 2.8 GHz was 139.0 (increasing 7.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 150.6. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.6). Three hour interval K indices: 13222222 (planetary), 13323322 (Boulder).
The background x-ray flux is at the class B7 level.
At the time of counting spots (see image time), spots were observed in 13 active regions in 2K resolution (SN: 254) and 12 active regions in 1K resolution (SN: 183) SDO images on the visible solar disk.
Region 12047 [S17W69] decayed slowly and lost all
trailing umbrae.
Region 12049 [S08W35] decayed slowly and quietly. The region has polarity
intermixing and could produce an M class flare.
Region 12050 [N12W32] decayed slowly and quietly.
Region 12051 [S10W78] decayed slowly and produced low level C flares. An M class flare
is still possible.
Region 12052 [S11E08] decayed slowly and quietly.
Region 12053 [N10E27] developed slowly and quietly.
Region 12054 [S11E51] decayed slowly and was quiet.
New region 12055 [N12E71] rotated partly into view on May 4 and was
numbered the next day by SWPC.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3386 [S18E09] was quiet and stable.
New region S3391 [N04E82] rotated partly into view and produced the
largest flare of the day. This is now AR 12056.
New region S3393 [S16W24] emerged with penumbra spots.
New region S3394 [S14E49] emerged with one spot.
New region S3395 [S12E42] emerged with a penumbra spot.
| Magnitude | Time (UTC) | Location | AR |
| C6.3 | 18:28 | N04E90 | S3391 |
| C2.5 | 21:18 | S11W86 | 12051 |
May 3-5: 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
A small coronal hole (CH614) in the northern hemisphere rotated across the central meridian on May 2. A small southern hemisphere coronal hole (CH615) was in an Earth facing position on May 4. An extension of a northern hemisphere coronal hole (CH616) could rotate into an Earth facing position on May 7-8.
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 poor to fair.
The geomagnetic field is expected to be quiet to unsettled on May 6 due to possible effects from CH614 and quiet to unsettled on May 7-8 due to a stream from CH615.
| 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 | ||||||||||
| 12047 | 2014.04.26 | 11 | 14 | 5 | S17W68 | 0150 | CAO | CAO |
 |
 |
|
| 12049 | 2014.04.26 2014.04.27 |
12 | 40 | 16 | S07W34 | 0210 | DAC | DSI |
 |
 |
beta-gamma area: 0310 |
| 12050 | 2014.04.27 | 1 | 4 | 1 | N12W33 | 0020 | HSX | HRX |
 |
 |
|
| S3374 | 2014.04.28 | S12W51 | plage | ||||||||
| 12051 | 2014.05.01 | 10 | 9 | 6 | S09W78 | 0170 | DAC | DAC |
 |
 |
beta-gamma |
| S3377 | 2014.05.01 | N02W54 |
 |
plage | |||||||
| 12052 | 2014.05.01 2014.05.02 |
6 | 14 | 8 | S12E08 | 0050 | DAO | DRI |
 |
 |
|
| S3379 | 2014.05.01 | S06E18 | plage | ||||||||
| S3380 | 2014.05.02 | N10E21 | plage | ||||||||
| S3381 | 2014.05.02 | S18W37 | plage | ||||||||
| S3382 | 2014.05.02 | S14W09 | plage | ||||||||
| 12053 | 2014.05.03 | 7 | 27 | 16 | N10E26 | 0050 | DAO | DRI |
 |
 |
area: 0100 |
| 12054 | 2014.05.03 2014.05.04 |
1 | 1 | 1 | S12E51 | 0040 | HSX | HAX |
 |
 |
location: S11E51 |
| S3385 | 2014.05.03 | N10E45 | plage | ||||||||
| S3386 | 2014.05.03 | 2 | 2 | S18E25 | 0008 | AXX |
 |
 |
|||
| 12055 | 2014.05.04 2014.05.05 |
3 | 7 | 5 | N10E67 | 0200 | DAO | DKO |
 |
 |
area: 0610 |
| S3389 | 2014.05.04 | S32E25 |
 |
plage | |||||||
| S3390 | 2014.05.04 | N12W31 |
 |
plage | |||||||
| S3391 | 2014.05.05 | 2 | 1 | N04E82 | 0180 | HAX |
 |
||||
| S3393 | 2014.05.05 | 2 | 1 | S16W24 | 0005 | BXO |
 |
||||
| S3394 | 2014.05.05 | 1 | 1 | S14E49 | 0010 | HRX |
 |
||||
| S3395 | 2014.05.05 | 1 | S12E42 | 0002 | AXX |
 |
|||||
| Total spot count: | 51 | 124 | 63 | ||||||||
| Sunspot number: | 131 | 254 | 183 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 91 | 171 | 109 | (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): | 79 | 89 | 101 | 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 | ||||
| 2013.02 | 104.3 | 101.8 | 38.0 | 58.4 (-0.3) | 6.11 |
| 2013.03 | 111.3 | 110.2 | 57.9 | 57.5 (-0.9) | 10.56 |
| 2013.04 | 124.8 | 125.9 | 72.4 | 57.9 (+0.4) | 5.40 |
| 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 | (75.6 projected, +0.6) | 5.68 |
| 2013.12 | 147.7 | 143.1 | 90.3 | (76.6 projected, +1.0) | 4.68 |
| 2014.01 | 157.4 | 152.4 | 82.0 | (77.6 projected, +1.0) | 5.44 |
| 2014.02 | 170.3 (cycle peak) |
166.3 | 102.8 (cycle peak) | (77.4 projected, -0.2) | 10.70 |
| 2014.03 | 149.9 | 148.5 | 92.2 | (77.9 projected, +0.5) | 4.88 |
| 2014.04 | 143.9 | 144.8 | 84.7 | (77.0 projected, -0.9) | 7.88 |
| 2014.05 | 132.8 (1) | 18.8 (2A) / 116.8 (2B) / 94.9 (2C) | (74.4 projected, -2.6) | (6.5) | |
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.
