Last major update issued on July 13, 2012 at 07:15 UTC.
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The geomagnetic field was quiet to active on July 12. Solar wind speed at SOHO ranged between 346 and 471 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 165.4 (increasing 20.5 over the last solar rotation). The Potsdam WDC planetary A index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 15.6). Three hour interval K indices: 44432212 (planetary), 23442312 (Boulder).
The background x-ray flux is at the class C1 level.
At midnight UTC the visible solar disk had 9 spotted active regions (in 2K resolution SDO images).
Region 11518 [N12W42] was quiet and could become spotless today.
Region 11519 [S16W32] was quiet and stable.
Region 11520 [S17W05] decayed slowly losing many small spots and some penumbral area. Opposite polarity umbrae within the huge penumbra are not as close as they were before the X1 flare. The complex magnetic layout has changed little over the last day and further X class flares are possible. Flares: C4.0/1F at 01:36, C3.1 at 08:05, major long duration X1.4 event peaking at 16:49 UTC. A wide and large CME was visible in STEREO imagery from 17:00 UTC. While there were no LASCO imagery at the time, later images displayed a full halo CME. The flare was associated with an above 10 MeV proton event.
Region 11521 [S22W23] decayed in the trailing spot section barely retaining rudimentary penumbra. The leader penumbra increased its area. Flare: M1.0/1F at 20:03 UTC
New region 11522 [N12W21] was first observed with spots on July 7 and was numbered by SWPC 5 days later when new flux emerged in the leading spot section.
New region 11523 [S28E31] emerged on July 11 and was numbered by SWPC the next day.
Spotted active regions not numbered or interpreted differently by NOAA/SWPC:
S1776 [S16W14] was mostly quiet and stable. Flare: C1.3 at 01:09 UTC.
S1777 [S12W08] was quiet and stable.
S1785 [S23W40] decayed slowly and quietly.
July 10-11: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
July 12: The X1 LDE in AR11520 was associated with a large and very wide CME. The core of the CME is likely Earth directed and could reach Earth before noon on July 14.
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 potentially geoeffective coronal holes are currently in or near Earth facing positions.
The above coronal hole map is based on a method where coronal holes are detected automatically. While the method may need some fine tuning, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using this method, the extent and intensity of both CHs are consistent with other data sources.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on July 13 and early on July 14. The CME observed on July 12 could reach Earth near noon on July 14 and cause minor to very severe geomagnetic storming lasting 18-30 hours. Quiet to active is likely on July 16.
|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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.
Click on image for higher resolution image) Compare to the previous day's image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue (blue-green) 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 count, location, classification and area probably includes ARs S1776 and S1777
|Total spot count:||82||119||57|
|Sunspot number:||132||209||127||(total spot count + 10 * number of spotted regions)|
|Weighted penumbral SN:||105||155||93||(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):||79||73||70||k * (sunspot number). k = 0.6 for SWPC, k = 0.35 (changed from 0.45 on March 1, 2011) for STAR SDO 2K, k = 0.55 for STAR SDO 1K|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
|2008.07||65.7 (SF minimum)||0.5||2.8 (-0.4)|
|2012.01||132.5||58.3||(65.0 projected, +1.6)||7.15|
|2012.02||106.5||33.1||(66.5 projected, +1.5)||8.81|
|2012.03||114.7||64.2||(67.2 projected, +0.7)||16.08|
|2012.04||113.0||55.2||(66.5 projected, -0.7)||10.10|
|2012.05||121.5||69.0||(64.8 projected, -1.7)||7.06|
|2012.06||119.6||64.5||(64.0 projected, -0.8)||10.08|
|2012.07||157.3 (1)||49.8 (2A) / 128.7 (2B)||(65.0 projected, +1.0)||(17.46)|
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 SIDC international sunspot number is typically 30-50% lower. 2B) Month average to date.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international Potsdam WDC ap indices.
This report has been prepared by Jan Alvestad. It is based on 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.