Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 25, 2012 at 07:40 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 minor storm on November 24. Solar wind speed at SOHO ranged between 346 and 451 km/s under the influence of CME effects. The interplanetary magnetic field was northwards after noon causing a decrease in the disturbance level.

Solar flux measured at 20h UTC on 2.8 GHz was 118.0 (increasing 1.0 over the last solar rotation). The Potsdam WDC planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 14.3). Three hour interval K indices: 54323211 (planetary), 44434311 (Boulder).

The background x-ray flux was at the class B3 level.

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

Region 11618 [N09W40] decayed slowly and was mostly quiet.
Region 11619 [N10W84] was quiet and stable.
Region 11620 [S13E01] gained a few spots and was quiet.
New region 11621 [N15E78] rotated into view.

Spotted regions not numbered by NOAA/SWPC:
S2059 [N08W35] was quiet and stable. The leader spot decayed a little and is still at the southeast edge of a trailing AR 11618 penumbra.
S2066 [S08W23] reemerged with a tiny spot.
[N16W80] decayed slowly and quietly.
S2070 [S23E47] decayed and lost the leader spots.
New region S2072 [S17E52] emerged with a tiny spot.
New region S2073 [S11E33] emerged with a tiny spot.
New region S2074 [N15E09] emerged with a tiny spot.
New region S2075 [S05W05] emerged with a tiny spot.

Coronal mass ejections (CMEs)

November 22: A filament eruption was observed starting in the southeast quadrant just after 08h UTC. LASCO C3 observed a faint and slow CME off the east limb from 10:42 UTC while the CME was visible in STEREO imagery from 10:09 UTC. There may be a very weak Earth directed component associated with this CME.
November 23: A filament eruption in the southern hemisphere was observed starting at 11:42 and peaking just after 14h UTC. In LASCO imagery it is difficult to determine if this CME was geoeffective due to a CME with an origin in an active region behind the northeast limb occurring a little earlier. STEREO imagery indicate that a faint component of the CME could be Earth directed.
November 24: 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 recurrent trans equatorial coronal hole (CH546) will likely rotate into an Earth facing position on November 27.

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.


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 to unsettled on November 25-26 due to CME effects, there's a chance of active intervals. Quiet conditions are likely on November 27-28.

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
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
2K 1K
11616 2012.11.13
5     N19W69 0020 DAO       spotless
11618 2012.11.15
22 33 17 N08W41 0340 EKC DAC  
11619 2012.11.15
4 1 1 N13W78 0100 ESO HSX

location: N10W84

SWPC data does not match reality

S2059 2012.11.16   4 2 N08W35 0020   CRO  
S2060 2012.11.17       S13W42           plage
S2061 2012.11.18       S33W32           plage
11620 2012.11.18
5 13 8 S12W00 0020 CSO CRO area: 0050
S2064 2012.11.19       S21E07           plage
S2065 2012.11.19       N13W49           plage
S2066 2012.11.20   1   S08W23 0000       plage
S2067 2012.11.21       S17W13         plage
S2068 2012.11.21   2 2 N16W80 0020   HRX  
S2069 2012.11.22       N18W23           plage
S2070 2012.11.23   1   S23E47 0000   AXX  
S2071 2012.11.23       S20E05         plage
11621 2012.11.24 1 1 1 N15E78 0060 HAX HSX   area: 0180
S2072 2012.11.24   1 1 S17E52 0000   AXX    
S2073 2012.11.24   1 1 S11E23 0000   AXX    
S2074 2012.11.24   1 1 N15E09 0000   AXX    
S2075 2012.11.24   1   S05W05 0000   AXX    
Total spot count: 37 60 34  
Sunspot number: 87 180 124  (total spot count + 10 * number of spotted regions)
Weighted SN: 67 84 58  (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): 52 63 68 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
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
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
2012.11 122.6 (1) 74.8 (2A) / 93.5 (2B) / 57.0 (2C) (61.2 projected, -0.3) (8.16)

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.