Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 15, 2014 at 04:35 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 active on October 14. Solar wind speed at SOHO ranged between 344 and 580 km/s. An unexpected disturbance began near noon.

Solar flux at 20h UTC on 2.8 GHz was 120 (decreasing 4.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 132.1. The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.1). Three hour interval K indices: 11123444 (planetary), 11123444 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 178) and 10 active regions using 1K resolution (SN: 145) SDO images on the visible solar disk.

Region 12185 [S17W55] decayed slowly and quietly.
Region 12186 [S22W17] was quiet and stable.
Region 12187 [S10E40] was quiet and stable.
Region 12188 [N17W27] was quiet and stable.
New region 12189 [N20E19] was first observed with spots on October 11, then decayed and was spotless for 2 days before reemerging with several spots on Oct.14.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3893 [N14E01] was quiet and stable.
S3900 [N04E61] developed slowly and quietly.
New region S3902 [S12E58] emerged with a few spots.
New region S3903 [N23E59] emerged with several spots. This is a reversed polarity region and could become interesting.
New region S3904 [N16W14] emerged with several spots.

An interesting region just behind the southeast limb produced 2 M class events during the evening, the second one was a very long duration M2 event with an associated nearly full halo CME.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
M1.1 18:37 SE limb    
M2.2(VLDE) 21:21 SE limb   large CME

Coronal mass ejections (CMEs)

October 12-14: 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. A recurrent northern hemisphere coronal hole (CH639) will likely rotate into an Earth facing position on October 17.

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 fair to good.

Forecast

The geomagnetic field is expected to be quiet to active on October 15 and quiet to unsettled on October 16-17 due to coronal hole 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: 0-30% 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
12184 2014.10.02
2014.10.03
      S17W82          

plage

real location: S24W68

S3879 2014.10.04       N16W55         plage
12185 2014.10.05
2014.10.06
2 5 2 S15W59 0010 BXO BXO location: S17W55
12186 2014.10.07 3 12 6 S21W19 0180 CSO CAO area: 0230

location: S22W17

S3887 2014.10.08       S08W49           plage
12187 2014.10.11 5 11 6 S09E44 0210 CSO EHO area: 0300
S3893 2014.10.11   5 3 N14E01 0010   AXX images/AR_S3893_20141013_2345.png  
12189 2014.10.11
2014.10.14
5 11 6 N21E18 0010 BXO CRO   area: 0030
S3896 2014.10.11       N18W42           plage
S3898 2014.10.12       S20E06           plage
12188 2014.10.13 5 9 6 N17W27 0010 BXO CRO area: 0030
S3900 2014.10.13   4 3 N04E61 0013   BXO  
S3902 2014.10.14   4 3 S12E58 0015   CRO    
S3903 2014.10.14   11 5 N23E59 0025   CRO    
S3904 2014.10.14   6 5 N16W14 0020   CRO    
Total spot count: 20 78 45  
Sunspot number: 70 178 145  (total spot count + 10 * number of spotted regions)
Weighted SN: 40 108 75  (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): 42 62 80 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
2014.10 126.0 (1)   37.0 (2A) / 81.9 (2B) / 81.7 (2C) (71.4 projected, -2.4) (7.2)

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 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.