Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 8, 2014 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 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 quiet on January 7. Solar wind speed at SOHO ranged between 325 and 423 km/s. A weak solar wind shock was observed at 14:24 at SOHO, the arrival of the CME observed on January 4. While the IMF was mostly southwards after the arrival of the CME, the total field was unimpressive and consequently caused only a minor geomagnetic disturbance.

Solar flux estimated at 22h UTC on 2.8 GHz was 200 (increasing 29.2 over the last solar rotation, the measurements at 18 and 20h were flare enhanced). The 90 day 10.7 flux at 1 AU was 146.3. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.5). Three hour interval K indices: 01000222 (planetary), 02112342 (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 10 active regions in 2K resolution (SN: 280) and 9 active regions in 1K resolution (SN: 205) SDO images on the visible solar disk.

Region 11942 [N11W33] decayed slowly and quietly.
Region 11943 [S14W14] was mostly unchanged.
C5+ flare: major long duration X1.2/2N proton event peaking at 18:32 UTC. The location of this event was in the trailing polarity section. A fast halo CME (exit speed near 2500 km/s) was observed in LASCO and STEREO imagery.
Region 11944 [S09W02] decayed slightly with a minor loss of penumbral area. There are still 3-4 magnetic delta structures. Further major flares are possible.
C5+ flare: M7.2/2B at 10:13 UTC.
Region 11946 [N09E10] developed further gaining penumbral area and spots. C5+ flare: M1.0/1N at 03:53 UTC.
Region 11947 [N11W80] decayed early in the day, then began to develop again. This region was the source of an
M3.6 flare at 03:47 UTC on January 8.
Region 11948 [N06E54] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S2995 [S16E23] gained trailing penumbra spots.
New region S2998 [S15E82] rotated into view.
New region S2999 [S32E09] emerged with a penumbra spot.
New region S3000 [S19E08] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

January 5-6: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 7: A full halo CME was observed after the X1 event in AR 11943. Given the exit speed, this CME could reach Earth during the first half of January 9.

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 high proton levels. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled January 8 due to CME effects. Quiet to major storm with a chance of severe storm intervals is likely on January 9 when the Jan.7 CME is expected to reach Earth. Quiet to minor storm is likely on January 10.

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
11938 2013.12.26
2013.12.27
1     S14W87 0010 AXX     rotated out of view
S2966 2013.12.29       S14W58           plage
S2971 2013.12.30       S22W45         plage
11943 2013.12.30
2013.12.31
  19 9 S11W21 0040 AXX BXO

location: S14W14

11942 2013.12.30
2013.12.31
1 6 1 N10W34 0010 AXX BXO  
11944 2013.12.31
2014.01.01
116 109 70 S09W03 1540 FKC FKC beta-gamma-delta

area: 2350

11945 2014.01.01
2014.01.02
      N11W53         plage
S2980 2014.01.01       S04W58           plage
S2983 2014.01.03       N21E13           plage
S2986 2014.01.03       S26W33           plage
11946 2014.01.04 14 33 26 N09W07 0210 DAC DHC

location: N09W03

area: 0460

S2988 2014.01.04       N20W18           plage
S2989 2014.01.04       N00W54           plage
S2990 2014.01.04       S09W58           plage
11948 2014.01.05
2014.01.06
1 1 1 N06E53 0060 HSX HSX area: 0140
S2992 2014.01.05       N17E09           plage
S2993 2014.01.05       N04W18           plage
11947 2014.01.05
2014.01.06
3 5 4 N11W84 0020 CRO DRO location: N11W80
S2995 2014.01.05   4 2 S16E23 0012   BXO  
S2996 2014.01.06       S01W00         plage
S2998 2014.01.07   1 1 S15E82 0300   HHX    
S2999 2014.01.07   1   S32E09 0003   AXX    
S3000 2014.01.07   1 1 S19E08 0004   AXX    
Total spot count: 136 180 115  
Sunspot number: 196 280 205  (total spot count + 10 * number of spotted regions)
Weighted SN: 159 218 153  (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): 118 98 113 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
2014.01 191.0 (1) 40.2 (2A) / 177.9 (2B) / 100.1 (2C) (67.6 projected, +0.2) (7.7)

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.