Last major update issued on July 31, 2014 at 04:45 UTC.
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[Solar cycles 23-24 (last update July 1, 2014)] [Cycle 24 progress (last update July 1, 2014) ]
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2009 - December 2012]
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The geomagnetic field was quiet on July 30. Solar wind speed at SOHO ranged between 283 and 336 km/s.
Solar flux at 20h UTC on 2.8 GHz was 152 (decreasing 26.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 133.3. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.3). Three hour interval K indices: 21110001 (planetary), 22012322 (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 13 active regions using 2K resolution (SN: 281) and 11 active regions using 1K resolution (SN: 182) SDO images on the visible solar disk.
Region 12121 [N07W38] was quiet and stable.
Region 12124 [S23E14] was quiet and stable.
Region 12125 [S13E17] developed slowly and gained spots.
Region 12126 [S10W42] was quiet and stable.
Region 12127 [S08E35] has a weak magnetic delta structure and could produce a minor M class flare.
Region 12128 [S21E35] was quiet and stable.
Region 12129 [S05W34] decayed slowly and quietly.
Region 12130 [S07E56] has a magnetic delta structure in the southernmost penumbra. An M class flare is possible.
Region 12131 [S19E47] developed slowly and quietly.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3680 [N13E01] reemerged with penumbra spots.
S3686 [N12E21] gained a few spots and was quiet.
New region S3689 [S19E74] emerged with penumbra spots.
New region S3690 [N22E58] emerged with a penumbra spot.
|Magnitude||Peak time (UTC)||Location||AR|
July 28-29: No obviously Earth directed CMEs were observed in LASCO and
July 30: A filament eruption in the northeast quadrant after 05h UTC was associated with a partial halo CME. This CME could reach Earth on August 2.
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 recurrent trans equatorial coronal hole (CH629) will likely rotate into an Earth facing position on July 31-August 1.
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 July 31 - August 1. A CME could cause unsettled and active intervals on August 2. Weak effects from CH629 could cause a few unsettled intervals on August 3-4.
|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.
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
|Total spot count:||55||151||72|
|Sunspot number:||145||281||182||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||98||189||110||(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):||87||98||100||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
|2014.01||157.4||152.4||81.8||(78.2 projected, +2.2)||5.44|
|166.3||102.3 (cycle peak)||(79.7 projected, +1.5)||10.70|
|2014.03||149.9||148.5||91.9||(80.5 projected, +0.8)||4.88|
|2014.04||143.9||144.8||84.7||(79.7 projected, -0.8)||7.88|
|2014.05||129.7||132.9||75.2||(77.1 projected, -2.6)||5.75|
|2014.06||122.0||125.8||71.0||(74.5 projected, -2.6)||6.72|
|2014.07||136.8 (1)||109.6 (2A) / 1123.3 (2B) / 84.7 (2C)||(71.5 projected, -3.0)||(4.5)|
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.