Last major update issued on March 26, 2014 at 06:15 UTC.
[Solar and geomagnetic data - last month (updated
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update March 1, 2014)] [Cycle 24 progress (last update March 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update March 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update March 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update March 1, 2014)]
[POES auroral activity level since October
2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated March 16, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]
The geomagnetic field was quiet to unsettled on March 24. Solar wind speed at SOHO ranged between 346 and 516 km/s. A disturbance related to the CME observed early on March 23 was observed arriving at ACE near 19:25 UTC.
Solar flux at 20h UTC on 2.8 GHz was 152.8 (decreasing 25.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.3. 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: 11122133 (planetary), 0012233x (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 11 active regions in 2K resolution (SN: 268) and 9 active regions in 1K resolution (SN: 178) SDO images on the visible solar disk.
Region 12008 [S12W60] decayed slowly and quietly.
Region 12010 [S13W39] decayed slowly and was mostly quiet.
Region 12012 [S16W23] decayed slowly and quietly.
Region 12013 [N14W22] decayed and had only penumbra spots left.
Region 12014 [S13W07] decayed slowly and was quiet.
Region 12015 [S13W68] decayed barely retaining positive polarity umbra.
Region 12017 [N10E20] was quiet and stable.
Region 12018 [N03E25] was quiet and stable.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3248 [S01E03] was quiet and stable.
S3262 [S13E33] was quiet and stable.
New region S3263 [S39W07] emerged at a high latitude with a penumbra spot.
March 24-25: No obviously Earth directed CMEs were observed in LASCO and
March 23: An asymmetric full halo CME was observed after the C5 LDE in AR 12014. The CME reached Earth late on March 25.
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 poor to fair.
The geomagnetic field is expected to be quiet to active on March 26 due to CME effects and quiet on March 27-28.
|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: 0-30% 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
SWPC has moved the region many degrees to the west
real location: S12W60
erroneous SWPC data, DAC and 1 spot is impossible
|Total spot count:||54||158||88|
|Sunspot number:||114||268||178||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||77||186||116||(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):||68||94||98||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
|2013.09||102.6||103.7||36.9||(72.8 projected, +3.8)||5.23|
|2013.10||132.1||131.2||85.6||(73.8 projected, +1.0)||7.71|
|2013.11||148.3||145.1||77.6||(72.7 projected, -1.1)||5.68|
|2013.12||147.7||143.1||90.3||(71.6 projected, -1.1)||4.68|
|2014.01||157.4||152.4||82.0||(71.6 projected, 0.0)||5.44|
|166.3||102.8 (cycle peak)||(70.9 projected, -0.7)||10.70|
|2014.03||150.4 (1)||115.3 (2A) / 143.0 (2B) / 119.5 (2C)||(71.0 projected, +0.1)||(4.8)|
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.