Last major update issued on February 11, 2015 at 04:20 UTC.
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The geomagnetic field was quiet to unsettled on February 10. Solar wind speed at SOHO ranged between 349 and 404 km/s.
Solar flux at 20h UTC on 2.8 GHz was 141.0 (decreasing 0.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 149.2. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.4). Three hour interval K indices: 12101113 (planetary), 12102222 (Boulder).
The background x-ray flux is at the class B5 level.
At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 191) and 7 active regions using 1K resolution (SN: 127) SDO images on the visible solar disk.
Region 12280 [S07W54] decayed slowly and still has a magnetic delta in a central penumbra. An M class flare is possible.
Region 12281 [N13W16] decayed slowly and quietly.
Region 12282 [N11E43] developed in the southern spot section and could produce another M class flare.
Spotted regions not numbered (or interpreted
differently) by SWPC:
S4198 [S24W17] was quiet and stable.
S4209 [N12W23] decayed slowly and quietly.
New region S4210 [N10E58] emerged to the east of AR 12282.
New region S4211 [S15E45] was observed with a penumbra spot.
New region S4212 [N28E17] emerged with a penumbra spot.
New region S4213 [N24W31] was observed with penumbra spots.
C2+ flares (GOES):
|Magnitude||Peak time (UTC)||Location||AR||Comment|
February 8-9: No obviously Earth directed CMEs were observed in LASCO
February 10: The M2 flare in AR 12282 just before midnight on February was associated with a large and wide CME. While most of the ejecta was seen off the east limb, there were weak extensions off the southwest limb and partly off the northwest limb. The partial halo CME could cause a glancing blow to the magnetosphere on February 13.
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 trans equatorial coronal hole (CH653) will rotate into an Earth facing position on February 10-12, CH653 has not been associated with geomagnetic disturbances during previous rotations. CH653 has displayed growth on February 9-10.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to unsettled on February 11-12. Weak geomagnetic effects associated with CH653 are possible on February 13-14. If there is a glancing blow from the CME observed after the M2 event in AR 12282 on February 9, there will be a chance of active intervals on February 13.
|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
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlay
rotated out of view
|Total spot count:||42||101||57|
|Sunspot number:||82||191||127||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||67||117||73||(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):||49||67||70||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
|Smoothed sunspot number||Average
|166.3||102.3 (cycle peak)||78.4 (+1.1)||10.70|
(likely solar max)
|2014.08||124.7||127.9||74.7||(76.2 projected, -2.4)||7.71|
|2014.09||146.6||148.1||87.6||(73.0 projected, -3.2)||9.78|
|2014.10||153.4||152.9||60.6||(70.5 projected, -2.5)||8.96|
|2014.11||154.8||151.4||70.1||(68.8 projected, -1.7)||9.33|
|2014.12||158.7||153.8||78.0||(67.7 projected, -1.1)||11.24|
|2015.01||141.9||137.3||67.0||(66.5 projected, -1.2)||9.46|
|2015.02||146.7 (1)||33.6 (2A) / 94.1 (2B) / 77.5 (2C)||(64.9 projected, -1.6)||(10.6)|
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 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.