Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 1, 2014 at 06:15 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 31. Solar wind speed at SOHO ranged between 325 and 582 km/s.

Solar flux at 20h UTC on 2.8 GHz was 121.2 (decreasing 6.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 142.4. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 12111121 (planetary), 11112222 (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 11 active regions using 2K resolution (SN: 159) and 10 active regions using 1K resolution (SN: 127) SDO images on the visible solar disk.

Region 12194 [S13W74] decayed quickly and quietly.
Region 12195 [N07W48] decayed slowly and quietly.
Region 12196 [S04W23] decayed slowly and quietly.
Region 12197 [S13W25] decayed slowly and quietly.
Region 12199 [S18E13] decayed and could soon become spotless.
Region 12200 [S17E34] decayed slowly and quietly.
Region 12201 [S05E52] developed slowly and has a weak magnetic delta structure. Further C class flaring is possible.
Region 12202 [N11E06] developed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3941 [S18W11] was quiet and stable.
New region S3955 [N06E67] emerged with a few spots.
New region S3956 [N12E23] emerged with a few spots.

A filament eruption near the southeast limb was associated with a long duration C2.6 event peaking near 05:35 UTC on November 1.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C8.2 01:01   12192  
C2.3 08:25 S05E59 12201  
C2.0/1F 09:23 S05E57 12201  

Coronal mass ejections (CMEs)

October 29-31: 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) rotated 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. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 1-2 due to effects from CH641 and quiet on November 3.

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
12194 2014.10.19
2014.10.21
1 1 1 S12W74 0020 HRX AXX area: 0010
12195 2014.10.21
2014.10.22
1 2 2 N07W50 0040 HAX CAO area: 0070
12197 2014.10.23
2014.10.24
  5 3 S12W24 0012   BXO  
12196 2014.10.23
2014.10.24
1 4 1 S05W24 0010 AXX CRO  
S3937 2014.10.25       S16W36            
S3941 2014.10.27   1 1 S17W11 0012   BXO  
12198 2014.10.27
2014.10.28
      S13W59           plage
12200 2014.10.28
2014.10.30
2 8 3 S16E33 0020 HRX CRO  
12199 2014.10.29
2014.10.30
  3   S17E09 0005   BXO location: S18E13
S3948 2014.10.29       S10E09           plage
12201 2014.10.29
2014.10.30
3 10 5 S05E51 0050 CAO DAC beta-delta

area: 0070

12202 2014.10.29
2014.10.30
3 7 6 N12E01 0030 CRO DRO area: 0060
S3951 2014.10.29       S22W22           plage
S3952 2014.10.30       N14E38         plage
S3955 2014.10.31   4 3 N06E67 0020   CRO    
S3956 2014.10.31   4 2 N12E23 0014   DRO    
Total spot count: 11 49 27  
Sunspot number: 71 159 127  (total spot count + 10 * number of spotted regions)
Weighted SN: 30 74 53  (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): 43 56 70 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
2014.10 153.4 (1)   92.1 (2A/2B) / 79.7 (2C) (71.4 projected, -2.4) (8.6)

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.