Last major update issued on March 24, 2014 at 04:50 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 on March 23. Solar wind speed at SOHO ranged between 402 and 524 km/s, weakly under the influence of a high speed stream from CH608.
Solar flux at 20h UTC on 2.8 GHz was 157.0 (decreasing 13.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.5. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.5). Three hour interval K indices: 22212122 (planetary), 12222322 (Boulder).
The background x-ray flux is at the class B8 level.
At the time of counting spots (see image time), spots were observed in 14 active regions in 2K resolution (SN: 310) and 13 active regions in 1K resolution (SN: 219) SDO images on the visible solar disk.
Region 12005 [N12W73] was mostly unchanged and
Region 12008 [S10W32] decayed slowly and quietly.
Region 12010 [S13W13] developed slowly and produced several low level C flares. The region has two magnetic delta structures. An M class flare is possible.
Region 12012 [S16E05] lost the leader spot.
Region 12013 [N15E03] was quiet and stable.
Region 12014 [S12E21] developed and has polarity intermixing. A minor M class flare is possible. C5+ flare: C5.0 long duration event peaking at 03:48 UTC. This event was associated with an asymmetric full halo CME.
Region 12015 [S14W42] developed a magnetic delta structure. A minor M class flare is possible.
Region 12016 [S27W07] decayed early in the day, then began to develop again in leading polarity.
Region 12017 [N10E47] gained penumbral area and appears to be maturing. Several low level C flares were recorded.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3226 [S10W47] decayed slowly and quietly. SWPC has moved AR 12008 14 degrees to the west of where it should be to include the spots in ARs S3226 and S3258, the original AR 12008 still has spots.
S3244 [N16W09] reemerged with a penumbra spot.
S3248 [N01E31] was quiet and stable.
S3258 [S05W47] decayed slowly and quietly.
New region S3259 [S20E52] emerged with a penumbra spot.
March 21: No obviously Earth directed CMEs were observed in LASCO and
March 22: A partial halo CME was observed after the LDE in AR 12005, it is uncertain if this CME has Earth directed extensions.
March 23: An asymmetric full halo CME was observed after the C5 LDE in AR 12014. The CME could reach Earth on March 26.
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 trans equatorial coronal hole (CH608) was in an Earth facing position on March 19-20.
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 on March 24-25 with some uncertainty on March 25 due to possible effects from the March 22 CME. Quiet to active conditions are possible on March 26 due to CME effects.
|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
|N11W61||trailing part of AR 12005|
SWPC has moved the region 14 degrees to the west and currently counts the spots of ARs S3226 and S3258.
real location: S10W32
rotated out of view
|Total spot count:||69||169||89|
|Sunspot number:||159||309||219||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||107||215||135||(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):||95||108||120||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||149.9 (1)||107.4 (2A) / 144.7 (2B) / 120.7 (2C)||(71.0 projected, +0.1)||(4.7)|
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.