Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 8, 2014 at 05:15 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update October 1, 2014)] [Cycle 24 progress (last update October 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update October 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update October 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update September 6, 2014)]

[New: Noon SDO sunspot count 1K 4K (large file)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated September 6, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on October 7. Solar wind speed at SOHO ranged between 332 and 433 km/s.

Solar flux at 20h UTC on 2.8 GHz was 125 (decreasing 30.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 133.5. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.3). Three hour interval K indices: 23100001 (planetary), 23002211 (Boulder).

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

At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 211) and 11 active regions using 1K resolution (SN: 147) SDO images on the visible solar disk.

Region 12178 [S02W63] decayed slowly and quietly.
Region 12179 [S11W48] reemerged with a penumbra spot.
Region 12181 [S12W74] decayed slowly and quietly.
Region 12182 [S14W29] decayed slowly and quietly.
Region 12183 [N12W02] developed slowly and quietly.
Region 12184 [S20E22] decayed slowly and quietly.
Region 12185 [S13E35] decayed slowly and quietly.
New region 12186 [S20E76] rotated into view.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3878 [S18W12] was quiet and stable.
S3879 [N14E36] was quiet and stable.
New region S3883 [N17E73] rotated into view.
New region S3884 [S06E17] emerged with a few penumbra spots.
New region S3885 [S35W06] emerged with a penumbra spot.
New region S3886 [S11W60] emerged with penumbra spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
         

Coronal mass ejections (CMEs)

October 5-7: 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]

No obvious coronal holes are currently in or near Earth facing positions.

Propagation

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

Forecast

The geomagnetic field is expected to be mostly quiet on October 8-10.

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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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 Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12177 2014.09.25       N13W82          

plage

12178 2014.09.27 1 3 2 S02W64 0080 HAX CSO area: 0140
12179 2014.09.27
2014.09.28
  1   S10W52 0001   AXX   location: S11W48
S3858 2014.09.27       N05W48         plage
12181 2014.09.28
2014.09.30
3 3 2 S12W73 0070 CAO CSO area: 0150
12182 2014.10.01
2014.10.03
7 17 10 S15W27 0050 CAO CAI  
12183 2014.10.01
2014.10.03
1 11 6 N13E02 0000 AXX BXO images/AR_12183_20141007_2345.png area: 0020
12184 2014.10.02
2014.10.03
2 13 5 S23E22 0010 BXO DRO  
S3874 2014.10.02       S08W38           plage
S3875 2014.10.03       N13W17         plage
S3878 2014.10.04   5 4 S18W12 0015   BXO images/AR_S3878_20141007_2345.png images/AR_S3878_20141006_2345.png  
S3879 2014.10.04   5 3 N14E36 0012   BXO  
12185 2014.10.05
2014.10.06
  4 1 S14E29 0010   BXO location: S13E35
12186 2014.10.07 1 2 2 S19E73 0080 HKX CKO   location: S20E76

area: 0300

S3883 2014.10.07   1 1 N17E73 0005   AXX    
S3884 2014.10.07   3 1 S06E17 0007   BXO    
S3885 2014.10.07   1   S35W06 0002   AXX    
S3886 2014.10.07   2   S11W60 0004   BXO    
Total spot count: 15 71 37  
Sunspot number: 75 211 147  (total spot count + 10 * number of spotted regions)
Weighted SN: 40 99 65  (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): 45 74 81 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.06 110.1 113.7 52.5 62.6 (+2.7) 12.60
2013.07 115.5 119.3 57.0 65.5 (+2.9) 9.47
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 (82.7 projected, +1.9) 7.88
2014.05 129.7 132.9 75.2 (82.3 projected, -0.4) 5.75
2014.06 122.0 125.8 71.0 (81.1 projected, -1.2) 6.72
2014.07 137.4 141.8 72.5 (79.4 projected, -1.7) 4.50
2014.08 124.7 127.9 74.7 (77.1 projected, -2.3) 7.71
2014.09 146.2   87.6 (73.8 projected, -3.3) 9.78
2014.10 136.0 (1)   25.5 (2A) / 112.7 (2B) / 94.2 (2C) (71.4 projected, -2.4) (5.9)

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 WDC-SILSO 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 GFZ 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.