Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 14, 2014 at 04:00 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 October 10, 2014)]

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

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated October 11, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on October 13. Solar wind speed at SOHO ranged between 283 and 441 km/s.

Solar flux at 20h UTC on 2.8 GHz was 113 (decreasing 19.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 131.8. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.5). Three hour interval K indices: 11101123 (planetary), 11202332 (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 9 active regions using 2K resolution (SN: 125) and 7 active regions using 1K resolution (SN: 91) SDO images on the visible solar disk.

Region 12185 [S16W43] developed slowly and quietly.
Region 12186 [S21W03] was quiet and stable.
Region 12187 [S09E54] decayed in the trailing spot section and was quiet.
New region 12188 [N16W12] emerged with several spots.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3879 [N16W42] decayed slowly and quietly.
S3893 [N14E18] gained a trailing penumbra spot.
S3895 [S17W78] was quiet and stable.
New region S3900 [N05E75] rotated into view.
New region S3901 [S04W67] emerged with a penumbra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
         

Coronal mass ejections (CMEs)

October 11-13: 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 small trans equatorial coronal hole (CH638) rotated across the central meridian on October 13-14.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet on October 14-15. Weak coronal hole effects are possible on October 16-17.

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
12183 2014.10.01
2014.10.03
      N13W82           plage
12184 2014.10.02
2014.10.03
      S17W68          

plage

real location: S24W55

S3879 2014.10.04   4   N16W42 0006   BXO  
12185 2014.10.05
2014.10.06
  5 3 S13W51 0015   CRO location: S16W43
12186 2014.10.07 5 7 4 S21W06 0180 CAO CSO area: 0260

location: S21W03

S3883 2014.10.07       N17W06           plage
S3887 2014.10.08       S08W36           plage
12187 2014.10.11 3 4 4 S10E54 0210 ESO EKO area: 0320
S3893 2014.10.11   4 1 N14E18 0010   BXO images/AR_S3893_20141013_2345.png  
S3894 2014.10.11       N20E22           plage
S3895 2014.10.11   1 1 S17W78 0005   AXX  
S3896 2014.10.11       N18W29           plage
S3898 2014.10.12       S20E19         plage
12188 2014.10.13 3 8 7 N17W13 0010 BXO CRO   area: 0040
S3900 2014.10.13   1 1 N05E75 0005   AXX    
S3901 2014.10.13   1   S04W67 0003   AXX    
Total spot count: 11 35 21  
Sunspot number: 41 125 91  (total spot count + 10 * number of spotted regions)
Weighted SN: 21 56 42  (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): 25 44 50 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
2014.10 126.5 (1)   34.7 (2A) / 82.8 (2B) / 82.2 (2C) (71.4 projected, -2.4) (6.5)

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.