Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 31, 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 October 10, 2014)]

[Noon SDO sunspot count 1K Reference: 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 on October 30. Solar wind speed at SOHO ranged between 308 and 410 km/s.

Solar flux at 20h UTC on 2.8 GHz was 140.4 (increasing 3.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 142.9. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.1). Three hour interval K indices: 11111112 (planetary), 11123322 (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 11 active regions using 2K resolution (SN: 180) and 9 active regions using 1K resolution (SN: 123) SDO images on the visible solar disk.

Region 12194 [S12W60] decayed slowly and quietly.
Region 12195 [N07W34] was quiet and stable.
Region 12196 [S04W10] was quiet and stable.
Region 12197 [S14W13] was quiet and stable.
New region 12199 [S18E25] emerged on October 29 and was numbered by SWPC the next day.
New region 12200 [S17E49] rotated into view on October 28 with SWPC numbering the region 2 days later.
New region 12201 [S06E67] rotared into view on October 29 and received its NOAA  number the following day.
New region 12202 [N12E17] emerged on October 29, SWPC numbered the region the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3941 [S15E02] reemerged with several penumbra spots.
New region S3952 [N14E51] emerged with a penumbra spot.
New region S3954 [N09W76] emerged with a penubmra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
M1.3 00:37   12192  
M3.5 01:35   12192  
M1.2 04:28   12192  
C3.5 05:46   12192  
C2.9 12:44      
C6.9 13:12   12201  
C2.3 15:09   12200  
C9.7 15:42   12192  
C3.4 17:58   12201  
C4.8/1N 23:01 S06E66 12201  

Coronal mass ejections (CMEs)

October 28-30: 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 northern hemisphere coronal hole (CH641) will likely rotate across the central meridian on October 29-30.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet to unsettled on October 31. Quiet to unsettled is possible on November 1-2 due to effects from CH641.

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
12192 2014.10.16
2014.10.17
4     S15W94 030 DKC     rotated out of view
12194 2014.10.19
2014.10.21
1 1 1 S13W62 0020 HAX HAX  
12195 2014.10.21
2014.10.22
1 11 3 N08W35 0050 HAX CSO  
12197 2014.10.23
2014.10.24
1 14 4 S12W16 0010 AXX BXO location: S14W13
12196 2014.10.23
2014.10.24
1 6 4 S04W12 0010 AXX CRO  
S3936 2014.10.25       S29W53           plage
S3937 2014.10.25       S16W23            
S3941 2014.10.27   4 4 S15E02 0012   BXO    
12198 2014.10.27
2014.10.28
1     S13W45 0000 AXX     plage
12200 2014.10.28
2014.10.30
5 11 4 S16E48 0020 CAO CRO  
12199 2014.10.29
2014.10.30
4 8 6 S17E23 0020 CRO BXO  
S3948 2014.10.29       S10E22         plage
12201 2014.10.29
2014.10.30
1 6 4 S05E65 0030 HAX DAO area: 0120
12202 2014.10.29
2014.10.30
2 7 3 N12E17 0013 BXO DRO  
S3951 2014.10.29       S22W09         plage
S3952 2014.10.30   1   N14E51 0003   AXX    
S3954 2014.10.30   1   N09W76 0002   AXX    
Total spot count: 21 70 33  
Sunspot number: 121 180 123  (total spot count + 10 * number of spotted regions)
Weighted SN: 44 94 57  (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): 73 63 68 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
2014.09 146.6 148.1 87.6 (73.8 projected, -3.3) 9.78
2014.10 155.1 (1)   89.8 (2A) / 92.8 (2B) / 81.5 (2C) (71.4 projected, -2.4) (8.8)

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.