Last major update issued on May 15, 2013 at 05:10 UTC.
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[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]
The geomagnetic field was quiet to unsettled on May 14. Solar wind speed at SOHO ranged between 336 and 428 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 147.9 (increasing 39.8 over the last solar rotation). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 11233222 (planetary), 11243212 (Boulder).
The background x-ray flux was at the class B9 level.
At midnight UTC the visible solar disk had 13 spotted active regions (in 2K resolution SDO images).
Region 11741 [S21W41] decayed slowly and quietly.
Region 11742 [N29W17] decayed slowly and quietly.
Region 11743 [N21W12] decayed slowly and was quiet.
Region 11744 [N04E02] was quiet and stable.
Region 11745 [N12E27] lost all positive polarity umbrae, however, there are many positive polarity penumbra spots and the region extends over a large area longitudinally.
Region 11746 [S28E27] was quiet and stable.
Region 11747 [S18E22] was quiet and stable.
Region 11748 [N11E66] is a compact region with a strong magnetic delta structure in the leading spot section. Some loss of penumbral area was observed after the X3 flare. Further M and X class flaring is possible. C5+ flares: X3.2 at 01:11 UTC. Additionally an X1.2 flare was recorded at 01:48 UTC on May 15. Both events were associated with at least partial halo CMEs.
Spotted regions not numbered by SWPC:
S2411 [S24E38] gained a few spots and was quiet.
S2416 [S22W26] was quiet and stable.
New region S2417 [S11E01] emerged with penumbra spots.
New region S2418 [S43E17] emerged with high latitude penumbra spots in a north-south polarity alignment.
New region S2419 [S15E63] emerged with a penumbra spot.
May 12-13: No obviously Earth directed CMEs were observed in LASCO
May 14: At least a partial halo CME was observed after the X3 event in AR 11748. The CME was fast and Earth could see a flanking impact on May 16.
May 15: A wide CME was observed after the X1 event in AR 11748. A flanking impact is possible on May 17.
Coronal hole history (since October
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A poorly defined trans equatorial coronal hole (CH570) was in an Earth facing position on May 13.
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 poor.
The geomagnetic field is expected to be quiet on May 15. On May 16 there's a chance of unsettled intervals due to possible effects from CH570. If there's a flanking impact from the CME observed early on May 14, active to minor storm conditions will be possible. May 17 could see unsettled to minor storm conditions due to CME effects.
|Coronal holes (1)||Coronal mass ejection (2)||M and X class flares (3)|
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 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.
|Active region||Date numbered
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlay
location at midnight: N17W85
|Total spot count:||62||177||74|
|Sunspot number:||142||317||184||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||105||215||112||(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):||85||111||101||k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
|2011.11||153.5 (cycle max)||96.7 (cycle max)||61.1 (+1.2)||5.55|
possible cycle 24 max
|2012.11||121.3||61.8||(59.1 projected, +0.5)||7.08|
|2012.12||108.6||40.8||(58.4 projected, -0.7)||3.44|
|2013.01||127.1||62.9||(58.0 projected, -0.4)||4.69|
|2013.02||104.3||38.0||(58.2 projected, +0.5)||6.11|
|2013.03||111.3||57.9||(57.8 projected, -0.4)||10.56|
|2013.04||124.8||72.4||(57.4 projected, -0.4)||5.40|
|2013.05||139.7 (1)||62.0 (2A) / 137.2 (2B) / 74.9 (2C)||(57.5 projected, +0.1)||(7.10)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
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) 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 Potsdam WDC ap indices.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.