Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 9, 2012 at 05:05 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 on November 8. Solar wind speed at SOHO ranged between 362 and 541 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 104.1 (decreasing 17.8 over the last solar rotation). 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: 11111002 (planetary), 10011211 (Boulder).

The background x-ray flux was at the class B2 level.

At midnight UTC the visible solar disk had 9 spotted active regions (in 2K resolution SDO images).

Region 11604 [N08W21] was quiet and stable.
Region 11606 [S17W04] decayed slowly losing the leader spots.
Region 11607 [N13W84] decayed slowly and quietly.
Region 11608 [S20E25] was quiet and stable.
Region 11609 [S15E46] was quiet and stable.
Region 11610 [S23E41] was quiet and stable.
New region 11611 [N12E67] rotated into view on Nov.7 and was numbered by SWPC the next day. The region produced the single flare on the visible disk, an M1.7 long duration event peaking at 02:23 UTC. This event was associated with a CME off the east limb.
New region 11612 [N07E76] rotated into view.

Spotted regions not numbered by NOAA/SWPC:
New region S2041 [N04E27] emerged with a tiny spot.

An active region just behind the southeast limb appears to be fairly active and could produce an M class flare. The largest flare of the day was backsided, possibly in old AR 11598, and was associated with a full halo CME and an increase in proton levels at Earth.

Coronal mass ejections (CMEs)

November 6-8: 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

A tran equatorial coronal hole (CH545) will likely rotate into an Earth facing position on November 10.

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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on November 9-12. Quiet to active conditions are possible on Nov.13 due to effects from CH545.

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
11602 2012.10.28
2012.10.29
      S19W71          

plage

11605 2012.11.01
2012.11.04
      N18W32         plage
11604 2012.11.02
2012.11.03
  2   N07W24 0000   BXO location: N08W21
S2028 2012.11.02       N26W35           plage
11606 2012.11.04   1 1 S15W10 0000   AXX location: S17W04
11608 2012.11.04
2012.11.05
1 3 3 S20E23 0010 HRX HRX location: S20E25
11607 2012.11.04
2012.11.05
2 1   N12W87 0090 DSO AXX area: 0000
S2033 2012.11.05       S18E05           plage
11609 2012.11.05
2012.11.06
4 9 4 S15E45 0040 CSO CRO  
11610 2012.11.06
2012.11.07
1 5 2 S24E36 0000 AXX BXO location: S23E41
S2037 2012.11.06       N23W49           plage
S2038 2012.11.07       S06E30         plage
11611 2012.11.07
2012.11.08
2 7 4 N12E66 0200 DSO DSO area: 0340
S2040 2012.11.07       N14E31         plage
11612 2012.11.08 1 1 1 N06E71 0070 HSX HSX   area: 0140
S2041 2012.11.08   1   N04E27 0000   AXX    
Total spot count: 11 30 15  
Sunspot number: 71 120 75  (total spot count + 10 * number of spotted regions)
Weighted SN: 34 46 31  (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): 43 42 41 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 98.0 (1) 14.0 (2A) / 52.4 (2B) / 50.7 (2C) (61.2 projected, -0.3) (8.02)

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.