Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 31, 2015 at 05:40 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 30. Solar wind speed at SOHO ranged between 294 and 379 km/s.

Solar flux at 20h UTC on 2.8 GHz was 121.2 (increasing 24.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.6. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.6). Three hour interval K indices: 21012213 (planetary), 21023312 (Boulder).

The background x-ray flux is at the class B9 level.

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 180) and 7 active regions using 1K resolution (SN: 107) SDO images on the visible solar disk.

Region 12440 [N18W58] decayed slowly and quietly.
Region 12441 [N14E09] decayed slowly and quietly.
Region 12442 [N15W20] decayed fairly quickly.
Region 12443 [N06E57] developed quickly in the trailing spot section adding penumbral area and spots. A magnetic delta formed and the region could produce a major flare.
Region 12444 [S05E48] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4860 [N18E65] decayed slowly and quietly.
New region S4861 [N11E38] emerged with tiny spots.
New region S4862 [S07E17] was observed with tiny spots within CH697.
New region S4863 [S38W04] was observed with a tiny spot at a high latitude.
New region S4864 [N03W60] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.3 00:50   12436 GOES15 attributed to AR 12443 by SWPC
C2.9 01:05   12443 GOES15  
C2.8 03:55   12443 GOES15  
C4.1 04:22   12443 GOES15  
C3.9 05:03   12436 GOES15 attributed to AR 12443 by SWPC
C2.5 05:45 N10E72 12443 GOES15  
C4.2 07:15   12443 GOES15  
C5.5 08:41   12443 GOES15 attributed to AR 12436 by SWPC
C4.6 10:18   12443 GOES15  
C2.4 11:54   12443 GOES15  
C3.1 13:01   12437 GOES15  
C4.2 13:24   12443 SDO/EVE  
C4.0 13:50   12443 SDO/EVE  
C5.9 14:22   12443 GOES15 C6.8 @ SDO/EVE
C5.8 15:10   12436 SDO/EVE some contribution from flare in AR 12443
C5.9 15:37   12437 GOES13 C8.0 @ SDO/EVE
C5.2 16:25   12443 GOES15  
C5.4 16:58   12443 SDO/EVE  
C3.8 17:43   12436 SDO/EVE  
C2.7 18:50   12443 SDO/EVE  
C2.7 19:37   12443 SDO/EVE  
C7.8 20:16   12443 GOES15  

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

Coronal mass ejections (CMEs)

October 28-30: 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 mostly quiet on October 31 and November 1. On November 2 a corotating interaction region associated with CH697 could cause unsettled to major storm conditions. These conditions will 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       N16W31          
S4843 2015.10.23       N19W53            
S4846 2015.10.25       S19W37            
12440 2015.10.25
2015.10.26
2 5 1 N19W57 0010 BXO BXO  
S4849 2015.10.26       N13W46            
S4850 2015.10.26       S02W39            
12441 2015.10.27 4 10 5 N14E08 0020 CRO CRO  
12442 2015.10.27
2015.10.28
4 5 3 N16W17 0020 CRO CRO

location: N15W20

S4853 2015.10.27       S18W42            
12443 2015.10.28
2015.10.29
25 46 24 N06E56 0560 EKC FKC beta-gamma-delta

area: 0940

12444 2015.10.28
2015.10.29
3 6 2 S04E46 0010 BXO BXO  
S4857 2015.10.28       N10W23            
S4860 2015.10.29   2   N18E65 0004   AXX  
S4861 2015.10.30   2   N11E38 0003   BXO    
S4862 2015.10.30   2 1 S07E17 0005   AXX    
S4863 2015.10.30   1   S38W04 0002   AXX    
S4864 2015.10.30   1 1 N03W60 0003   AXX    
Total spot count: 38 80 37  
Sunspot number: 88 180 107  (total spot count + 10 * number of spotted regions)
Weighted SN: 54 96 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): 97 99 91 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 (103.6)   57.2 (2A) / 59.1 (2B) / 71.4 (2C) (66.7 projected, -0.9) (14.0)

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.