Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 22, 2012 at 05:30 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 21. Solar wind speed at SOHO ranged between 349 and 498 km/s under the influence of a high speed coronal hole stream.

Solar flux measured at 20h UTC on 2.8 GHz was 140.4 (increasing 10.4 over the last solar rotation). The (Potsdam WDC - temp. replaced by the USAF Ap on Nov.21) planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 33221111 (planetary), 42331211 (Boulder).

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

At midnight UTC the visible solar disk had 8 spotted active regions (in 2K resolution SDO images).

Region 11613 [S23W71] was quiet and stable.
Region 11616 [N20W28] decayed and could soon become spotless.
Region 11618 [N08W00] developed quickly in the central and trailing spot sections with several magnetic delta structures forming. Further M class flaring is likely. Flares: M1.4/1N at 06:56, C4.1 at 09:41, M3.5 at 15:30 UTC. The latter flare was associated with a small CME which could have Earth directed components.
Region 11619 [N10W42] decayed slowly and quietly.
Region 11620 [S12E43] was quiet and stable.

Spotted regions not numbered by NOAA/SWPC:
S2059 [N08E06] was quiet and stable. The leader spots in this region appear to be merging with AR 11618 due to the expansion of that region.
New region S2067 [S20E19] emerged with tiny spots.
New region S2068 [N17W36] emerged very quickly and could produce C flares.

Coronal mass ejections (CMEs)

November 19: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
November 20: A full halo CME was observed after noon following a filament eruption near AR 11619. This CME could reach Earth on November 23.
November 21: While most of the ejecta from the CME associated with the M3 event in AR 11618 was directed eastwards, components of the CME could be Earth directed.

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 to fair.

Forecast

The geomagnetic field is expected to be quiet on November 22 becoming quiet to active on November 23-24 due to CME effects.

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
11613 2012.11.09
2012.11.11
1 1 1 S24W69 0040 HSX HSX

area: 0120

location: S23W71

11614 2012.11.10
2012.11.11
      N14W62        

plage

11615 2012.11.11       N07W76           plage
11617 2012.11.13
2012.11.16
      S18W88          
11616 2012.11.13
2012.11.14
2 5   N19W28 0010 DRO BXO  
S2051 2012.11.14       S12W54           plage
S2053 2012.11.14       S33W46           plage
S2055 2012.11.14       S27W39           plage
11618 2012.11.15
2012.11.17
27 49 34 N09E01 0300 EKC EKC beta-gamma-delta

area: 0700

11619 2012.11.15
2012.11.17
6 7 3 N10W39 0150 HSX CAO

area: 0260

S2059 2012.11.16   3 2 N08E06 0050   HAX  
S2060 2012.11.17       S13W03           plage
S2061 2012.11.18       S33E07           plage
11620 2012.11.18
2012.11.20
1 3 3 S08E44 0020 HSX HSX area: 0090

location: S12E43

S2064 2012.11.19       S21E46           plage
S2065 2012.11.19       N13W10         plage
S2066 2012.11.20       S10E18         plage
S2067 2012.11.21   7 1 S20E19 0000   BXO    
S2068 2012.11.21   9 4 N17W36 0120   DAO    
Total spot count: 37 84 48  
Sunspot number: 87 164 118  (total spot count + 10 * number of spotted regions)
Weighted SN: 65 119 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): 52 57 65 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
2012.11 122.3 (1) 66.0 (2A) / 94.3 (2B) / 56.3 (2C) (61.2 projected, -0.3) (9.20)

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.