Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 20, 2015 at 05:35 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 (November 16, 2015)  

Recent activity

The geomagnetic field was quiet to unsettled on November 19. Solar wind speed at SOHO ranged between 396 and 500 km/s.

Solar flux at 20h UTC on 2.8 GHz was 108.1 (decreasing 6.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.1. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.3). Three hour interval K indices: 32231010 (planetary), 41132210 (Boulder).

The background x-ray flux is at the class B3 level.

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 205) and 7 active regions using 1K resolution (SN: 105) SDO images on the visible solar disk.

Region 12452 [S14W52] was quiet and stable.
Region 12454 [N05W14] decayed slowly and quietly. This is AR 12456 to SWPC.
Region 12455 [N16W29] was quiet and stable.
New region 12457 [N11E78] rotated partly into view on November 18 and was numbered the next day by SWPC. The region is compact and could produce C flares.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4899 [S21W02] developed slowly and quietly.
S4902 [N11W09] was quiet and stable.
S4904 [N25W38] reemerged with a tiny spot.
New region S4906 [N14E33] emerged early in the day, then began to decay slowly.
New region S4907 [N19E41] emerged with tiny spots.
New region S4908 [S22E19] emerged with tiny spots.
New region S4909 [S05W61] emerged with tiny spots.
New region S4910 [N03E00] was observed with a tiny spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

November 17-19: 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 northern hemisphere coronal hole (CH701) will likely rotate into an Earth facing position on November 21-22, CH701 may be too far to the north to become geoeffective.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet on November 20-23.

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
12452 2015.11.10
2015.11.11
  2 1 S08W70 0005   BXO images/AR_12452_20151119_2345.png images/AR_12452_20151118_2345.png location: S14W52
S4884 2015.11.10       S19W44            
12453 2015.11.12
2015.11.13
      N06W80            
12454 2015.11.12
2015.11.13
8 13 8 N11W13 0020 CRO DRI area: 0050

location: N05W14

SWPC has renumbered this as AR 12456

12455 2015.11.13
2015.11.14
  2   N15W32 0004   BXO

location: N16W29

S4899 2015.11.15   15 6 S21W02 0030   BXO images/AR_S4899_20151119_2345.png images/AR_S4899_20151118_2345.png  
S4900 2015.11.15       N24W49            
S4901 2015.11.15       S25W41            
S4902 2015.11.16   30 10 N11W09 0020   DRI images/AR_S4902_20151119_2345.png images/AR_S4902_20151118_2345.png this is AR 12454 to SWPC
S4904 2015.11.17   1   N25W38 0003   AXX    
12456 2015.11.18 10     N06W14 0040 DAI       see AR 12454 and AR S4902
12457 2015.11.18
2015.11.19
3 12 8 N12E70 0020 BXO DAC area: 0200

location: N11E78

S4906 2015.11.19   3 1 N14E33 0009   BXO    
S4907 2015.11.19   2   N19E41 0003   BXO    
S4908 2015.11.19   2   S22E19 0005   BXO    
S4909 2015.11.19   2   S05W61 0005   BXO    
S4910 2015.11.19   1 1 N03E00 0006   AXX    
Total spot count: 21 85 35  
Sunspot number: 51 205 105  (total spot count + 10 * number of spotted regions)
Weighted SN: 29 96 46  (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): 56 113 89 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) 14.02
2015.11 (110.0)   41.0 (2A) / 64.7 (2B) / 90.1 (2C) (65.0 projected, -2.1) (16.3)

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.