Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 17, 2012 at 07:55 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 16. Solar wind speed at SOHO ranged between 350 and 453 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 138.3 (decreasing 13.1 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: 7.4). Three hour interval K indices: 22111232 (planetary), 12112221 (Boulder).

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

At midnight UTC the visible solar disk had 12 spotted active regions (in 2K resolution SDO images).

Region 11610 [S23W69] decayed further and was quiet.
Region 11611 [N12W42] decayed slowly and quietly.
Region 11612 [N08W29] added a few spots and was quiet.
Region 11613 [S25W05] gained a few tiny spots.
Region 11614 [N14E07] decayed slowly and quietly.
Region 11615 [N07W06] decayed slowly and quietly.
Region 11616 [N19E36] decayed slowly and was quiet.
New region 11617 [S18W17] emerged on November 13 and was numbered by SWPC 3 days later.

Spotted regions not numbered by NOAA/SWPC:
S2055 [S22E16] was quiet and stable.
S2056 [N08E67] was quiet and stable.
S2058 [N09E31] developed slowly and quietly.
New region S2059 [N11E76] rotated into view with a tiny spot. The region has reversed polarities. The region may have been the source of the largest flare of the day, an impuslive C8.4 event at 15:39 UTC.

Coronal mass ejections (CMEs)

November 14-16: 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. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to occasionally unsettled on November 17-19.

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
11608 2012.11.04
2012.11.05
      S20W87           plage
11609 2012.11.05
2012.11.06
      S14W66           plage
11610 2012.11.06
2012.11.07
10 7 4 S22W63 0160 CSO CAO location: S23W69

 

11611 2012.11.07
2012.11.08
1 5 2 N12W43 0130 HSX CSO

area: 0180

11612 2012.11.08 1 10 4 N08W32 0030 HRX DRO area: 0040

location: N08W29

11613 2012.11.09
2012.11.11
4 15 8 S23W05 0100 CSO CSO beta-gamma

area: 0190

location: S25W05

11614 2012.11.10
2012.11.11
24 28 16 N15E05 0240 DAI DAI

location: N14E07

11615 2012.11.11 6 5 4 N07W06 0020 CRO BXO  
S2045 2012.11.11       S15W45           plage
S2047 2012.11.12       S09W44           plage
S2048 2012.11.12       N23W52         plage
11617 2012.11.13
2012.11.16
2 4 3 S18W18 0010   BXO  
11616 2012.11.13
2012.11.14
13 16 7 N19E37 0110 DSO CRO area: 0050
S2051 2012.11.14       S12E11           plage
S2052 2012.11.14       N42E04           plage
S2053 2012.11.14       S32E03           plage
S2055 2012.11.14   6 3 S22E16 0010   AXX  
S2056 2012.11.15   4 3 N08E67 0020   CRO  
S2057 2012.11.15       N23W41         plage
S2058 2012.11.15   9 4 N09E31 0050   DRO  
S2059 2012.11.16   1   N11E76 0000   AXX   reversed polarities
Total spot count: 61 110 58  
Sunspot number: 141 230 168  (total spot count + 10 * number of spotted regions)
Weighted SN: 92 142 90  (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): 85 81 92 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
2012.11 116.7 (1) 45.1 (2A) / 84.6 (2B) / 55.8 (2C) (61.2 projected, -0.3) (9.43)

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.