Last major update issued on January 26, 2015 at 03:50 UTC.
[Solar and geomagnetic data - last month (updated
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update January 1, 2015)] [Cycle 24 progress (last update January 1, 2015) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2015)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2015)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 3, 2015)]
[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]
[POES auroral activity level October
2009 - December 2012]
[Solar polar fields vs solar cycles - updated January 25, 2015]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]
The geomagnetic field was quiet to unsettled on January 25. Solar wind speed at SOHO ranged between 310 and 379 km/s.
Solar flux at 20h UTC on 2.8 GHz was 126.6 (decreasing 4.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 146.9. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8). Three hour interval K indices: 12001113 (planetary), 11012223 (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: 188) and 8 active regions using 1K resolution (SN: 140) SDO images on the visible solar disk.
Region 12266 [S05W85] was quiet and stable.
Region 12268 [S10E34] developed in the trailing spot section with a small magnetic delta forming. A minor M class flare is possible.
Region 12269 [N07W07] was quiet and stable.
New region 12271 [N17E10] emerged on January 23 and was numbered by SWPC 2 days later. The region has polarity intermixing and could produce C flares.
Spotted regions not numbered (or interpreted differently) by SWPC:
S4166 [S27W10] reemerged with a penumbra spot.
New region S4174 [S10E74] rotated into view with penumbra spots.
New region S4175 [N12E75] rotated into view.
New region S4176 [S03E07] emerged with several spots. The region has reversed polarities.
New region S4177 [S03W04] emerged with a few spots.
C2+ flares (GOES):
|Magnitude||Peak time (UTC)||Location||AR||Comment|
January 23-25: No obviously Earth directed CMEs were observed in LASCO imagery. There may have been a weak CME after 15h UTC on January 24 following a filament eruption.
[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 small southern hemisphere coronal hole (CH651) was in an Earth facing position on January 25.
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 to fair.
The geomagnetic field is expected to be quiet to unsettled on January 26. On January 27 there is a slight chance of CME effects due to a filament eruption on January 24. On January 28-29 a weak coronal hole stream could cause some unsettled intervals.
|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: 0-30% 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.
|Active region||Date numbered
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlay
|Total spot count:||25||98||60|
|Sunspot number:||65||188||140||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||45||128||90||(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):||39||66||77||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 ap
|166.3||102.3 (cycle peak)||78.4 (+1.1)||10.70|
(likely solar max)
|2014.07||137.4||141.8||72.5||(78.6 projected, -1.1)||4.50|
|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||138.0 (1)||72.4 (2A) / 89.8 (2B) / 72.3 (2C)||(66.5 projected, -1.2)||(9.0)|
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.