Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 3, 2015 at 04:50 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 (November 1, 2015)
Solar cycle Solar cycles 23-24 (November 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (November 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 (November 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (November 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 November 2. Solar wind speed at SOHO ranged between 286 and 352 km/s. A co-rotating interaction region associated with CH697 was observed arriving at ACE at 22:20 UT, several hours later than expected. Geomagnetic activity has increased early on November 3. Solar wind density is still increasing and has reached very high levels. The main disturbance associated with CH697 will likely arrive within a few hours.

Solar flux at 20h UTC on 2.8 GHz was 122.0 (increasing 40.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.0. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.3). Three hour interval K indices: 10012301 (planetary), 10112322 (Boulder).

The background x-ray flux is at the class B4 level.

At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 180) and 6 active regions using 1K resolution (SN: 123) SDO images on the visible solar disk.

Region 12441 [N14W32] was quiet and stable.
Region 12442 [N16W53] developed in the trailing spot section and decayed elsewhere. The region has minor polarity intermixing and could produce an M class flare. This is currently AR 12445 to SWPC.
Region 12443 [N06E16] decayed in the trailing spot section. The region produced far fewer flares than during the previous days. An M class flare is still possible.
Region 12446 [N15W18] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4860 [N19E26] was quiet and stable.
S4869 [N15W13] decayed slowly and quietly.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C6.3/1N 00:50 N16W44 12442 GOES15 C7.9 @ SDO/EVE
C2.2 05:12 N15W46 12442 GOES15  
C3.3 06:37 N15W47 12442 GOES15  
C7.2 10:00 N13W49 12442 GOES15  
C2.8 14:48   12443 SDO/EVE  
C5.0 15:00 N10E23 12442 GOES15 attributed to AR 12443 by SWPC
C2.3 15:29   12443 SDO/EVE  
C2.4 16:22   12443 SDO/EVE  
C2.0 17:33   12442 GOES15  

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

Coronal mass ejections (CMEs)

October 31-November 2: 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) was in 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 poor. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to major storm on November 3-4 becoming quiet to unsettled on November 5 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       N16W73         location: N19W65
12441 2015.10.27 2 6 1 N15W32 0010 BXO BXO  
12442 2015.10.27
2015.10.28
  25 12 N16W62 0360   DKI

beta-gamma

location: N15W53

 

12443 2015.10.28
2015.10.29
36 82 47 N06E16 0590 FKC FKC beta-gamma-delta

area: 0920

12444 2015.10.28
2015.10.29
      S04E03            
S4860 2015.10.29   3 1 N19E26 0006   AXX  
S4861 2015.10.30       N11W01            
S4862 2015.10.30       S07W22            
S4865 2015.10.31       S12W13          
12446 2015.10.31
2015.11.01
3 2 1 N15W18 0010 BXO BXO  
S4867 2015.10.31       N32E17            
S4868 2015.10.31       S01E01            
12445 2015.11.01 13     N15W55 0240 DAC       part of AR 12442
S4869 2015.11.01   2 1 N15W13 0006   AXX  
Total spot count: 54 120 63  
Sunspot number: 94 180 123  (total spot count + 10 * number of spotted regions)
Weighted SN: 69 140 83  (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): 103 99 105 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
2014.09 146.6 148.1 130.0 101.9 (-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 78.9 (-3.3) 10.73
2015.05 120.0 122.6 88.8 (76.3 projected, -2.6) 8.29
2015.06 122.3 126.1 66.5 (72.6 projected, -3.7) 13.15
2015.07 107.0 110.8 66.4 (68.9 projected, -3.7) 8.83
2015.08 105.4 108.0 64.6 (67.7 projected, -1.2) 14.58
2015.09 101.7 102.7 78.1 (68.0 projected, +0.3) 15.78
2015.10 104.1 103.3 61.7 (67.1 projected, -0.9) 13.8
2015.11 (123.2)   6.1 (2A) / 91 (2B) / 77.3 (2C) (65.0 projected, -2.1) (6.0)

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.