Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 19, 2012 at 05:15 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update November 1, 2012)] [Cycle 24 progress (last update November 1, 2012) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 1, 2012)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 1, 2012)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 4, 2012)]

[POES auroral activity level since October 2009 - updated October 7, 2012]
[Solar polar fields vs solar cycles - updated June 27, 2011]

Recent activity

The geomagnetic field was quiet to unsettled on November 18. Solar wind speed at SOHO ranged between 350 and 451 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 141.0 (decreasing 14.5 over the last solar rotation). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.8). Three hour interval K indices: 23222202 (planetary), 12221101 (Boulder).

The background x-ray flux was at the class B4 level.

At midnight UTC the visible solar disk had 14 spotted active regions (in 2K resolution SDO images).

Region 11611 [N12W70] was quiet and stable.
Region 11612 [N07W57] decayed slowly and quietly.
Region 11613 [S23W32] decayed slowly and quietly.
Region 11614 [N14W21] decayed slowly and quietly.
Region 11615 [N07W33] produced a C5.7 flare at 04:07 UTC and decayed afterwards. The region could soon become spotless.
Region 11616 [N19E11] decayed slowly and quietly.
Region 11618 [N08E38] developed slowly and produced 2 small C flares. There's polarity intermixing and the region could produce C flares and maybe even a minor M class flare. A C7.0 flare was observed at 02:28 UTC on Nov.19.
Region 11619 [N10E02] developed quickly and has major flare potential. There's a small magnetic delta structure in a central penumbra.

Spotted regions not numbered by NOAA/SWPC:
S2055 [S24E02] was quiet and stable.
S2059 [N08E48] developed slowly and was mostly quiet.
S2060 [S13E36] was quiet and stable.
New region S2061 [S33E46] emerged with a tiny spot.
New region S2062 [S12E83] rotated into view.
New region S2063 [S12W35] emerged with tiny spots.

Coronal mass ejections (CMEs)

November 16-18: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.

Coronal holes

Coronal hole history (since October 2002)
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.

Coronal hole map

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.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to occasionally unsettled on November 19-21.

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 green.
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.

Active solar regions

Click on image for higher resolution image) 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 (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
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC STAR SDO SWPC STAR Current Previous
2K 1K
11611 2012.11.07
2012.11.08
1 1 1 N12W71 0120 HSX HSX

area: 0160

11612 2012.11.08 3 2 1 N10W57 0030 HRX AXX area: 0010

location: N07W57

11613 2012.11.09
2012.11.11
4 3 1 S23W33 0100 CSO CSO

area: 0190

11614 2012.11.10
2012.11.11
8 18 5 N15W21 0020 CRI BXO

 

11615 2012.11.11 3 4 1 N07W34 0010 BXO BXO  
11617 2012.11.13
2012.11.16
      S18W46           plage
11616 2012.11.13
2012.11.14
10 8 3 N19E11 0030 CRO BXO area: 0010
S2051 2012.11.14       S12W15           plage
S2052 2012.11.14       N42W22           plage
S2053 2012.11.14       S33W07         plage
S2055 2012.11.14   4   S26W08 0000   AXX  
11618 2012.11.15
2012.11.17
8 21 8 N08E37 0090 EAI CSI beta-gamma

2 or 3 clustered regions, split is being considered

11619 2012.11.15
2012.11.17
19 34 20 N10E03 0160 DAO DKC beta-gamma-delta

area: 0500

S2059 2012.11.16   17 5 N08E48 0050   CRI  
S2060 2012.11.17   1 1 S13E36 0000   AXX  
S2061 2012.11.18   1   S33E46 0000   AXX    
S2062 2012.11.18   2 2 S12E83 0100   CSO    
S2063 2012.11.18   2   S12W35 0000   AXX    
Total spot count: 56 118 48  
Sunspot number: 136 258 158  (total spot count + 10 * number of spotted regions)
Weighted SN: 85 151 81  (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): 82 90 87 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.09 133.8 78.0 59.5 (+0.5) 12.27
2011.10 137.3 88.0 59.9 (+0.4) 8.28
2011.11 153.5 96.7 61.1 (+1.2) 5.55
2011.12 141.3 73.0 63.4 (+2.3) 3.78
2012.01 132.5 58.3 65.5 (+2.1) 7.15
2012.02 106.5 32.9 66.9 (+1.4)
possible cycle 24 max
8.81
2012.03 114.7 64.3 66.8 (-0.1) 16.08
2012.04 113.0 55.2 64.6 (-2.2) 10.10
2012.05 121.5 69.0 (61.2 projected, -3.4) 7.06
2012.06 119.6 64.5 (58.8 projected, -2.4) 10.08
2012.07 133.9 66.5 (58.6 projected, -0.2) 13.90
2012.08 115.4 63.1 (60.4 projected, +1.8) 7.96
2012.09 122.9 61.5 (61.8 projected, +1.4) 8.07
2012.10 123.3 53.3 (61.5 projected, -0.3) 9.97
2012.11 119.1 (1) 55.1 (2A) / 91.8 (2B) / 56.8 (2C) (61.2 projected, -0.3) (9.26)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
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) 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 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.