Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 1, 2015 at 04:30 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data from 2003.01 (October 1, 2015)
Solar cycle Solar cycles 23-24 (October 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (October 1, 2015) Noon SDO sunspot count 1K Reference: 4K (large file) (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (October 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (October 1, 2015) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (October 13, 2015)  

Recent activity

The geomagnetic field was quiet to unsettled on October 31. Solar wind speed at SOHO ranged between 310 and 408 km/s.

Solar flux at 20h UTC on 2.8 GHz was 118.5 (increasing 30.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.7. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 01112123 (planetary), 00112313 (Boulder).

The background x-ray flux is at the class B8 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 191) and 5 active regions using 1K resolution (SN: 93) SDO images on the visible solar disk.

Region 12440 [N18W73] decayed slowly and quietly.
Region 12441 [N14W05] decayed slowly and quietly.
Region 12442 [N15W31] decayed slowly in the leading spot section while slow development was observed in the trailing spots.
Region 12443 [N06E44] developed further in the trailing and intermediate spot sections. The magnetic delta from the previous day disappeared while a small delta formed in another nearby penumbra. A major flare is possible.
Region 12444 [S05E33] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4860 [N20E53] was quiet and stable.
New region S4866 [N14E09] emerged with several spots.
New region S4867 [N32E43] emerged with a tiny spot.
New region S4868 [S01E27] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C3.8 (LDE) 06:35 N07E54 12443 GOES15  
C5.2 15:02   12443 GOES15  
C2.1 17:28 N06E51 12443 GOES15  
M1.0 17:52 N06E51 12443 GOES15 C8.8 @ SDO/EVE
C6.6 19:07   12443 GOES15  
C9.9/1N 19:33 N06E50 12443 GOES15 M1.0 @ SDO/EVE
C2.7 20:44 N06E49 12443 GOES15  
C5.8 21:18 N05E50 12443 GOES15  
C6.1 23:04 N06E46 12443 GOES15  
C2.7 23:59   12443 GOES15  

Flare activity (SDO/EVE/ESP XRS-B proxy)

Coronal mass ejections (CMEs)

October 29-31: No obviously Earth directed CMEs were observed in available LASCO 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 recurrent trans equatorial coronal hole (CH697) will rotate into an Earth facing position on October 30-November 1.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet to active on November 1. On November 2 a co-rotating interaction region associated with CH697 could cause unsettled to severe storm conditions. Unsettled to major storm conditions likely continue on November 3-4 due to effects from CH697.

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 overlays
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12439 2015.10.22       N16W45            
S4846 2015.10.25       S19W50            
12440 2015.10.25
2015.10.26
1 1 1 N18W72 0010 AXX AXX area: 0005
S4849 2015.10.26       N13W59            
S4850 2015.10.26       S02W52            
12441 2015.10.27 3 9 3 N15W06 0010 BXO BXO  
12442 2015.10.27
2015.10.28
1 5 2 N16W35 0010 AXX DRO

location: N15W31

12443 2015.10.28
2015.10.29
28 66 32 N07E43 0640 EKC FKC beta-gamma-delta

area: 1050

12444 2015.10.28
2015.10.29
  1   S04E31 0001   AXX  
S4857 2015.10.28       N10W36            
S4860 2015.10.29   3   N20E53 0003   BXO  
S4861 2015.10.30       N11E25          
S4862 2015.10.30       S07E04          
S4863 2015.10.30       S38W17          
S4866 2015.10.31   14 5 N14E09 0060   DRO    
S4867 2015.10.31   1   N32E43 0001   AXX    
S4868 2015.10.31   1   S01E27 0001   AXX    
Total spot count: 33 101 43  
Sunspot number: 73 191 93  (total spot count + 10 * number of spotted regions)
Weighted SN: 43 117 59  (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): 80 105 79 k * (sunspot number)
As of July 1, 2015: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.85 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO) (4)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.02 170.3
(cycle peak)
166.3 146.1 (cycle peak) 110.5 (+1.2) 10.70
2014.04 143.9 144.8 112.5 116.4 (+2.1) (solar max) 7.88
2014.08 124.7 127.9 106.9 108.3 (-4.3) 7.71
2014.09 146.6 148.1 130.0 101.9 (-6.4) 9.78
2014.10 153.4 152.9 90.0 97.3 (-4.6) 8.96
2014.11 154.8 151.4 103.6 94.7 (-2.6) 9.33
2014.12 158.7 153.8 112.9 92.2 (-2.5) 11.24
2015.01 141.9 137.3 93.0 89.3 (-2.9) 9.46
2015.02 129.1 126.0 66.7 86.1 (-3.2) 9.92
2015.03 125.9 124.6 54.5 82.2 (-3.9) 16.14
2015.04 128.8 129.7 75.3 (78.7 projected, -3.5) 10.73
2015.05 120.0 122.6 88.8 (75.9 projected, -2.8) 8.29
2015.06 122.3 126.1 66.5 (72.2 projected, -3.7) 13.15
2015.07 107.0 110.8 66.4 (68.5 projected, -3.7) 8.83
2015.08 105.4 108.0 64.6 (67.3 projected, -1.2) 14.58
2015.09 101.7 102.7 78.1 (67.6 projected, +0.3) 15.78
2015.10 (104.1)   59.6 (2A/2B) / 72.0 (2C) (66.7 projected, -0.9) (13.8)

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).
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.
4) Updated to new data set from WDC-SILSO on July 1, 2015

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 Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.