The geomagnetic field was quiet to unsettled on May 9. Solar wind speed at SOHO ranged between 345 and 539 km/s.
Solar flux at 20h UTC on 2.8 GHz was 154.5 (increasing 20.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 125.6. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.4). Three hour interval K indices: 10031333 (planetary), 11022333 (Boulder).
The background x-ray flux is at the class B6 level.
At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 227) and 9 active regions using 1K resolution (SN: 164) SDO images on the visible solar disk.
Region 12335 [S15W44] decayed further and was quiet.
Region 12337 [S17W23] developed slowly and quietly.
Region 12338 [N04W21] decayed slowly and quietly.
Region 12339 [N11E20] displayed signs of decay and
became magnetically less complex. The region has polarity intermixing and could
produce C and M class flares.
Region 12340 [S08E39] has minor polarity intermixing and was quiet.
Region 12341 [S20E48] was quiet and stable.
New region 12342 [N18E63] rotated into view on May 8 and was numbered by
SWPC the next day.
Spotted regions not numbered (or interpreted
differently) by SWPC:
S4450 [N15E36] was quiet and stable.
New region S4453 [N08E53] emerged with a few penumbra spots.
New region S4454 [S08E07]emerged with penumbra spots.
| Magnitude | Peak time (UTC) | Location | AR | Recorded by | Comment |
| C7.4 (LDE) | 01:34 | N14E77 | 12342 | GOES15 | CME SDO/EVE: C9.6 @ 01:40. Flare location @ AIA335: N17E79 |
| C3.0 | 08:13 | N14E35 | 12339 | GOES15 |
May 7-9: No obviously Earth directed CMEs were observed.
[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 recurrent extension (CH667) of the southern polar coronal hole rotated across the central meridian on May 8-9 and may be associated with a co-rotating interaction region.
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.
The geomagnetic field is expected to be quiet to unsettled on May 10. On May 11-12 effects from CH667 and a co-rotating interaction region could cause unsettled to minor storm conditions.
| 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.
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 overlays |
Comment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SWPC | Magnetic (SDO) |
SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 12335 | 2015.04.30 | 8 | 12 | 6 | S16W42 | 0040 | CAO | CRO |
 |
 |
|
| 12338 | 2015.05.02 2015.05.03 |
4 | 3 | N05W24 | 0020 | CRO | AXX |
 |
 |
||
| 12336 | 2015.05.02 2015.05.03 |
N13W71 | |||||||||
| 12337 | 2015.05.02 2015.05.03 |
4 | 13 | 6 | S17W23 | 0020 | CRO | DRO |
 |
 |
area: 0050 |
| S4438 | 2015.05.03 | N05W12 | |||||||||
| S4439 | 2015.05.03 | N12W05 | |||||||||
| 12339 | 2015.05.03 2015.05.04 |
40 | 67 | 43 | N12E24 | 0840 | FKC | FKC |
 |
 |
beta-gamma area: 1140 location: N11E20 |
| S4441 | 2015.05.04 | N13W30 | |||||||||
| S4442 | 2015.05.04 | S29W31 |
 |
||||||||
| S4444 | 2015.05.05 | S03W05 | |||||||||
| S4445 | 2015.05.05 | S04W30 | |||||||||
| 12340 | 2015.05.06 2015.05.07 |
5 | 8 | 5 | S09E38 | 0040 | CAO | CAO |
 |
 |
|
| 12341 | 2015.05.06 2015.05.07 |
1 | 2 | 1 | S20E47 | 0070 | HSX | HSX |
 |
 |
area: 0130 |
| S4449 | 2015.05.06 | N26W24 |
 |
||||||||
| S4450 | 2015.05.07 | 11 | 7 | N15E36 | 0030 | BXO |
 |
 |
|||
| S4451 | 2015.05.07 | S17W08 | |||||||||
| 12342 | 2015.05.08 2015.05.09 |
4 | 5 | 4 | N18E63 | 0030 | CRO | DRO |
 |
 |
|
| S4453 | 2015.05.09 | 3 | 1 | N08E53 | 0010 | BXO |
 |
||||
| S4454 | 2015.05.09 | 3 | 1 | S08E07 | 0010 | BXO |
 |
||||
| Total spot count: | 66 | 127 | 74 | ||||||||
| Sunspot number: | 136 | 227 | 164 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 100 | 156 | 103 | (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): | 82 | 79 | 90 | 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 | ||||
| 2013.12 | 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 | 80.8 (+2.4) | 4.88 |
| 2014.04 | 143.9 | 144.8 | 84.7 | 81.9 (+1.1) (solar max) | 7.88 |
| 2014.05 | 129.7 | 132.9 | 75.2 | 80.5 (-1.4) | 5.75 |
| 2014.06 | 122.0 | 125.8 | 71.0 | 79.7 (-0.8) | 6.72 |
| 2014.07 | 137.4 | 141.8 | 72.5 | 78.5 (-1.2) | 4.50 |
| 2014.08 | 124.7 | 127.9 | 74.7 | 75.5 (-3.0) | 7.71 |
| 2014.09 | 146.6 | 148.1 | 87.6 | 70.8 (-4.7) | 9.78 |
| 2014.10 | 153.4 | 152.9 | 60.6 | 67.3 (-3.5) | 8.96 |
| 2014.11 | 154.8 | 151.4 | 70.1 | (64.9 projected, -2.4) | 9.33 |
| 2014.12 | 158.7 | 153.8 | 78.0 | (62.6 projected, -2.3) | 11.24 |
| 2015.01 | 141.9 | 137.3 | 67.0 | (60.4 projected, -2.2) | 9.46 |
| 2015.02 | 129.1 | 126.0 | 44.8 | (58.7 projected, -1.7) | 9.92 |
| 2015.03 | 125.9 | 124.6 | 38.4 | (56.3 projected, -2.4) | 16.14 |
| 2015.04 | 128.8 | 129.7 | 54.4 | (53.7 projected, -2.6) | 10.3 |
| 2015.05 | (128.3) | 25.8 (2A) / 88.9 (2B) / 82.7 (2C) | (51.5 projected, -2.2) | (7.3) | |
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.
