Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 7, 2014 at 06:00 UTC. Minor update posted at 19:10 UTC

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update January 1, 2014)] [Cycle 24 progress (last update January 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 1, 2014)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated December 16, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was very quiet on January 6. Solar wind speed at SOHO ranged between 327 and 418 km/s.

Solar flux estimated at 20h UTC on 2.8 GHz was 204 (increasing 28.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 145.4. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.5). Three hour interval K indices: 00100011 (planetary), 10101231 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time) spots were observed in 12 active regions in 2K resolution (SN: 318) and 9 active regions in 1K resolution (SN: 195) SDO images on the visible solar disk.

Region 11937 [S15W82] was mostly quiet and stable
Region 11938 [S14W70] decayed slowly and quietly.
Region 11942 [N10W19] decayed, however, a positive polarity spot emerged inside the negative polarity area causing weak polarity intermixing. The region was the origin of an eruptive event late in the day, this event may have been associated with a CME (imagery for the hours after the event is poor when this is written).
Region 11943 [S13W03] wdecayed slowly and quietly.
Region 11944 [S09E12] still has several fairly minor magnetic delta structures. M flares are possible, and there's a small chance of an X flare.
C5+ flare: C7.1/1F at 00:19 UTC.
Region 11945 [N11W37] decayed slowly and quietly.
Region 11946 [N09E10] developed further and gained a weak magnetic delta structure. C and minor M class flares are possible. The region was the source of an impulsive M1.0 flare at 03:53 UTC on January 7.
New region 11947 [N11W70] emerged on January 5 and was numbered by SWPC the next day.
New region 11948 [N06E67] rotated into view on January 5 and got its NOAA number the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S2971 [S22W32] reemerged with a penumbra spot.
S2995 [S18E27] was quiet and stable.
New region S2996 [S01E13] emerged with a penumbra spot.

AR 11937 behind the southwest limb produced a large proton flare which peaked at 07:45 UTC. This event was associated with a halo CME.

Minor update added at 19:10 UTC: A relatively weak solar wind shock was observed arriving at ACE near 14:20 UTC. Although Bz has been southwards, the total field of the IMF has been unimpressive. Two major flares have been observed so far today. AR 11944 produced an M7.2/2B flare at 10:13 UTC. Only a minor CME was observed after this event. Then, beginning just after 18h and peaking at 18:32 UTC, AR 11943 and 11944 both contributed to an X1.2 long duration event. The event apparently began in AR 11943 and quickly spread to AR 11944. A fast CME was observed in STEREO-A at the time. This CME could reach Earth on January 9 and cause active to major storm conditions, possibly with severe storm intervals.

Coronal mass ejections (CMEs)

January 5-6: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 4: A full halo CME was observed late in the day after the M4 event in AR 11943. This CME could reach Earth on January 7.

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 (CH599) will likely rotate into an Earth facing position on January 9-10.

Coronal hole map

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is very poor due to a proton event. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to minor storm with a chance of major storm intervals on January 7-8 due to CME effects. Quiet conditions are likely on January 9.

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 2K resolution) 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 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
11937 2013.12.25
2013.12.26
21 6 3 S13W85 0160 DAI DAO

 

11938 2013.12.26
2013.12.27
1 2 1 S14W73 0010 HRX CRO  
S2966 2013.12.29       S14W45           plage
S2971 2013.12.30   1   S22W32 0002   AXX    
11943 2013.12.30
2013.12.31
1 16 5 S11W07 0010 AXX BXO area: 0035

location: S13W03

11942 2013.12.30
2013.12.31
3 14 3 N10W20 0020 CRO CRO  
11944 2013.12.31
2014.01.01
112 121 69 S09E11 1415 FKC FKC beta-gamma-delta

area: 2600

S2977 2013.12.31       N14W55           plage
11945 2014.01.01
2014.01.02
1 1 1 N11W39 0010 AXX AXX area: 0004
S2980 2014.01.01       S04W45           plage
S2983 2014.01.03       N21E26           plage
S2984 2014.01.03       N38W44           plage
S2986 2014.01.03       S26W20           plage
11946 2014.01.04 11 29 20 N09E07 0140 DAC DAC beta-gamma-delta

location: N09E10

area: 0400

S2988 2014.01.04       N20W05           plage
S2989 2014.01.04       N00W41           plage
S2990 2014.01.04       S09W45         plage
11948 2014.01.05
2014.01.06
1 1 1 N06E67 0060 HSX HSX area: 0140
S2992 2014.01.05       N17E22         plage
S2993 2014.01.05       N04W05         plage
11947 2014.01.05
2014.01.06
4 3 2 N11W70 0030 CRO DRO  
S2995 2014.01.05   3   S18E27 0008   AXX  
S2996 2014.01.06   1   S01E13 0002   AXX    
Total spot count: 155 198 105  
Sunspot number: 245 318 195  (total spot count + 10 * number of spotted regions)
Weighted SN: 189 232 139  (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): 147 111 107 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)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
possible cycle 24 max
8.81
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 59.6 (-0.1) 3.44
2013.01 127.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 38.0 58.4 (-0.3) 6.11
2013.03 111.3 57.9 57.5 (-0.9) 10.56
2013.04 124.8 72.4 57.9 (+0.4) 5.40
2013.05 131.4 78.7 59.9 (+2.0) 9.73
2013.06 110.1 52.5 62.6 (+2.7) 12.60
2013.07 115.5 57.0 (65.4 projected, +2.8) 9.47
2013.08 114.6 66.0 (67.8 projected, +2.4) 8.27
2013.09 102.6 36.9 (70.1 projected, +2.3) 5.23
2013.10  132.1 85.6 (70.0 projected, -0.1) 7.71
2013.11  148.3 77.6 (68.1 projected, -1.9) 5.68
2013.12 147.7 90.3 (67.4 projected, -0.7) 4.6
2014.01 189.5 (1) 33.8 (2A) / 174.8 (2B) / 99.7 (2C) (67.6 projected, +0.2) (8.2)

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 the 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.