Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 13, 2012 at 04:55 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 active on November 12. Solar wind speed at SOHO ranged between 273 and 438 km/s. A low speed coronal hole caused a slow increase in solar wind speed and density after 13h UTC and a geomagnetic disturbance began after 16h UTC. A solar wind shock, likely associated with the CME observed on November 9, was observed at ACE just after 22h UTC. This caused a significant increase in geomagnetic activity and the geomagnetic field has since been at active to minor storm levels.

Solar flux measured at 20h UTC on 2.8 GHz was 143.8 (increasing 6.8 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: 6.9). Three hour interval K indices: 21000124 (planetary), 10001313 (Boulder).

The background x-ray flux was at the class B6 level.

At midnight UTC the visible solar disk had 11 spotted active regions (in 2K resolution SDO images).

Region 11608 [S19W28] reemerged with tiny spots.
Region 11609 [S16W06] decayed slowly and quietly.
Region 11610 [S23W09] developed slowly in the leading spot section while decay was observed in the trailing spots. The region produced 3 small C flares and has a fairly simple magnetic layout.
Region 11611 [N12E14] was quiet and stable.
Region 11612 [N08E23] was quiet and stable.
Region 11613 [S24E45] developed signficantly with two magnetic delta structures forming, one of them with very poor separation between opposite polarity umbrae. This caused a sudden increase in flare activity and the region produced the strongest flare of the day, an M2.0 event at 23:28 UTC. An impulsive major M6.0 flare was recorded at 02:04 UTC on November 13.
Region 11614 [N15E60] developed and became a compact region with a weak magnetic delta structure in a central penumbral area. M flares are possible.
Region 11615 [N08E47] was quiet and stable.

Spotted regions not numbered by NOAA/SWPC:
S2040 [N14W22] was quiet and stable.
New region S2047 [S09E08] emerged with a tiny spot.
New region S2048 [N26W03] emerged as a reversed polarities region.

Coronal mass ejections (CMEs)

November 10: A small CME, possibly with a weak Earth directed component, was observed following a filament eruption near AR 11608 starting at approx. 05h UTC.
November 11-12: 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 trans equatorial coronal hole (CH545) was in 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 very poor. Propagation on long distance northeast-southwest paths is fair to good.

Forecast

The geomagnetic field is expected to be unsettled to minor storm on November 13 due to CME and CH effects and quiet to unsettled on November 14-15.

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
11605 2012.11.01
2012.11.04
4     N16W82 0010 BXO       plage

maybe SWPC observed AR S2046?

11604 2012.11.02
2012.11.03
      N07W84           plage
11606 2012.11.04       S15W66           plage
11608 2012.11.04
2012.11.05
  2   S20W31 0000   AXX   location: S19W28
11609 2012.11.05
2012.11.06
3 6   S14W10 0010 HRX BXO area: 0000
11610 2012.11.06
2012.11.07
51 41 18 S22W10 0550 EKI EAI beta-gamma

area: 0380

S2038 2012.11.07       S06W22           plage
11611 2012.11.07
2012.11.08
12 17 8 N15E13 0250 EHO DSO area: 0380

location: N12E14

S2040 2012.11.07   5 3 N14W22 0010   BXO  
11612 2012.11.08 1 1 1 N09E25 0060 HSX HSX area: 0140

location: N08E23

S2041 2012.11.08       N04W25           plage
11613 2012.11.09
2012.11.11
10 12 8 S22E43 0170 DSO DSC beta-gamma-delta

area: 0320

location: S24E45

11614 2012.11.10
2012.11.11
19 18 12 N16E58 0350 FHO DSC beta-gamma-delta

location: N15E60

SWPC classification is obviously in error

11615 2012.11.11 8 8 4 N10E48 0160 CAO CRO area: 0020

location: N08E47

S2045 2012.11.11       S15E07         plage
S2046 2012.11.11       N15W76         plage
S2047 2012.11.12   1   S09E08 0000   AXX    
S2048 2012.11.12   1 1 N26W03 0000   AXX   reversed polarities
Total spot count: 108 112 55  
Sunspot number: 188 222 135  (total spot count + 10 * number of spotted regions)
Weighted SN: 156 140 83  (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): 113 78 74 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
2012.11 108.2 (1) 28.2 (2A) / 70.5 (2B) / 53.7 (2C) (61.2 projected, -0.3) (6.54)

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.