Last major update issued on February 12, 2014 at 06:20 UTC.
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[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update February 1, 2014)] [Cycle 24 progress (last update February 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update February 1, 2014)]
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[Archived reports since January 2003 (last update February 1, 2014)]
[POES auroral activity level since October
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[Solar polar fields vs solar cycles - updated February 1, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]
The geomagnetic field was quiet to unsettled on February 11. Solar wind speed at SOHO ranged between 373 and 565 km/s.
Solar flux at 20h UTC on 2.8 GHz was 172.2 (increasing 46.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 150.0. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 21200013 (planetary), 21201213 (Boulder).
The background x-ray flux is at the class C2 level.
At the time of counting spots (see image time) spots were observed in 18 active regions in 2K resolution (SN: 402) and 15 active regions in 1K resolution (SN: 274) SDO images on the visible solar disk.
Region 11971 [S13W43] developed slowly and quietly.
Region 11973 [N04W18] was quiet and stable.
Region 11974 [S12W06] decayed slowly and was quiet. SWPC has still not managed to split off AR S3098 and are counting these two groups as one.
Region 11975 [S13W76] decayed slowly and quietly.
Region 11976 [S14E37] was mostly quiet and stable. C flares are possible.
Region 11977 [S11E64] was quiet and stable.
New region 11978 [N05W39] emerged on February 10 and was numbered by SWPC the next day.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3098 [S12E05] developed quickly and has become capable of producing major flares, an X class flare is possible. There are several magnetic delta structures within the region. C5+ flares: M1.7/1N at 03:31, long duration C8.4/1F peaking at 13:57, M1.8 at 16:51, C5.9/1F at 22:15 UTC. The region was the source of an M3.7 flare at 04:25 UTC on February 12.
S3102 [S20W19] reemerged with a penumbra spot.
S3105 [S14E47] was quiet and stable.
S3106 [N26W27] lost the southern spots and gained a new penumbra spot further north.
New region S3111 [N17W04] emerged with penumbra spots.
New region S3112 [S32E48] emerged with a penumbra spot.
New region S3113 [N17E03] emerged with a penumbra spot.
New region S3114 [N30W10] emerged with a penumbra spot.
New region S3115 [N13W37] emerged with a penumbra spot.
New region S3116 [N15W25] emerged with several spots.
New region S3117 [S13W43] emerged with a penumbra spot.
February 9-10: No obviously Earth directed CMEs were observed in LASCO and
February 11: A partial halo CME was observed after 11h UTC following a filament eruption near AR 11978 in the northwest quadrant. It is uncertain if the CME has any Earth directed components.
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
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 on February 12-14.
|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
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.
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
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlay
SWPC has this as part of AR 11974
|S3105||2014.02.09||5||3||S14E47||0210||DSO||SWPC has this as part of AR 11976|
|Total spot count:||81||222||124|
|Sunspot number:||151||402||274||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||116||283||185||(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):||91||141||151||k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K|
|Month||Average solar flux||International sunspot number
|Smoothed sunspot number||Average ap
|2011.11||153.5||96.7 (cycle peak)||61.1 (+1.2)||5.55|
|2013.08||114.6||118.3||66.0||(69.0 projected, +3.5)||8.27|
|2013.09||102.6||103.7||36.9||(73.0 projected, +4.0)||5.23|
|2013.10||132.1||131.2||85.6||(74.0 projected, +1.0)||7.71|
|2013.11||148.3||145.1||77.6||(72.9 projected, -1.1)||5.68|
|2013.12||147.7||143.1||90.3||(71.8 projected, -1.1)||4.68|
|152.4||82.0||(71.0 projected, -0.8)||5.44|
|2014.02||180.0 (1)||71.4 (2A) / 181.6 (2B) / 106.5 (2C)||(71.2 projected, +0.2)||(7.9)|
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 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 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.