Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 15, 2024 at 07:25 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data since 2003.01 (November 6, 2024)
Solar cycle Solar cycles 23-25 (November 1, 2024) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (November 1, 2024) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (August 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (November 1, 2024) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (November 1, 2024) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (October 13, 2024) Cycle 25 spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing Research: Solar Cycle 25 Started on November 17, 2019 with 365 Days Smoothing
Calculating the Strength of Solar Cycle 25 Using 365-day Smoothing

Recent activity

The geomagnetic field was at quiet to unsettled levels on November 14. What appears to have been a weak transient was observed arriving at ACE just after 03:30 UT. The origin may have been the November 10 CME. Solar wind speed at SOHO ranged between 340 and 448 km/sec, averaging 393 km/sec (+29 compared to the previous day). The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at background levels all day.

Solar flux density measured at 20h UT on 2.8 GHz was 146.8 - decreasing 18.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 185.93. In comparison SC24 peaked on June 28, 2014 at 145.50 while SC23 peaked on February 23, 2002 at 198.15. Current SC25 peak: 185.93 on May 15, 2024). The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.9). Three hour interval K indices: 13112333 (planetary), 13212333 (Boulder), 14113453 (Andenes).

The background x-ray flux is at the class C1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 232) and in 9 active regions using 1K resolution (SN: 151) SDO/HMI images.

AR 13886 [S06W75] decayed slowly and quietly.
AR 13889 [S09W28] lost spots, area and all magnetic delta configurations. There is still polarity intermixing and an M flare is possible. C1 flares: C1.2 @ 02:47, C1.3 @ 04:36, C1.7 @ 08:03, C1.4 @ 12:25, C1.2 @ 14:06, C1.6 @ 15:08, C1.2 @ 16:14, C1.4 @ 16:31, C1.6 @ 20:27 UT
AR 13892 [S11W11] was mostly quiet and stable. C1 flares: C1.6 @ 07:11 UT
AR 13893 [S19E49] gained a few spots and has polarity intermixing. An M1.1 flare was recorded at 01:46 UT on November 15. C1 flares: C1.6 @ 20:12 UT
New AR 13894 [N23E44] emerged on November 13 and was numbered the next day by SWPC as slow development persisted.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10347 [S04W10] reemerged with tiny spots.
S10349 [N12W42] reemerged with tiny spots.
New region S10355 [N10E21] emerged with tiny spots.
New region S10356 [N03E39] emerged with tiny spots.
New region S10357 [S17E57] emerged with a tiny spot.
New region S10358 [S15E16] was observed with tiny spots in an old plage area.
New region S10359 [S13E29] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 08:55   13889? GOES16  
C2.9 09:13   13886 GOES16  
C2.7 11:53   13889 GOES16  
C2.8 12:46   13891 GOES16  
C2.8 15:38 S08W24 13889 GOES16  

Coronal mass ejections (CMEs)

November 12-14: No obviously Earth directed CMEs were observed.

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 northern hemisphere positive polarity coronal hole (CH1254) was Earth facing on November 8-14. Another recurrent positive polarity northern hemisphere coronal hole (CH1255) will be Earth facing on November 14-16.

Propagation

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

Forecast

The geomagnetic field is expected to be at quiet to unsettled levels on November 15-16 and then quiet to active on Nov. 17-19 due to effects from CH1255.

Coronal holes (1) Coronal mass ejections (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). 4K 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 officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. 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. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.

Active region SWPC date numbered
STAR detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlays
Comment
SWPC/
USAF
Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
13884 2024.11.02
2024.11.02
      S07W83        

location: S07W81

13886 2024.11.03
2024.11.03
1 3 1 S07W76 0010 AXX BXO

location: S06W75

13890 2024.11.04
2024.11.09
      S12W68           location: S13W65
13891 2024.11.05
2024.11.11
      S15W42        

location: S16W38

13889 2024.11.06
2024.11.07
25 55 35 S09W29 0430 FKI FKI beta-gamma

area: 0650

location: S09W28

S10337 2024.11.07       S11W58            
13892 2024.11.08
2024.11.11
4 12 8 S11W15 0020 BXO CRO

location: S11W11

S10342 2024.11.10       S17W53            
S10343 2024.11.10       N17W35            
S10344 2024.11.10       S05W24            
S10345 2024.11.10       N28W54            
S10347 2024.11.11   4 1 S04W10 0010   BXO    
13893 2024.11.12
2024.11.13
4 9 5 S19E48 0040 CSO DSO area: 0090

location: S19E49

S10349 2024.11.12   2 1 N12W42 0006   AXX    
S10350 2024.11.12       S27W39            
13894 2024.11.13
2024.11.14
12 11 7 N24E44 0030 BXO DRO area: 0070
S10352 2024.11.13       N04E38          
S10353 2024.11.13       N22E04          
S10355 2024.11.14   4   N10E21 0010   BXO    
S10356 2024.11.14   4 2 N03E39 0010   BXO    
S10357 2024.11.14   1   S17E57 0002   AXX    
S10358 2024.11.14   5 1 S15E16 0010   BXO    
S10359 2024.11.14   2   S13E29 0003   BXO    
Total spot count: 46 112 61  
Sunspot number: 96 232 151  (total spot count + 10 * number of spotted regions)
Weighted SN: 61 133 82  (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): 106 128 121  

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.02 170.3
(cycle peak)
166.3 146.1 (SC24 peak) 110.5 10.70
2014.04 143.9 144.8 112.5 116.4 (SC24 solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(SC24 peak)
2019.11 70.2 68.7 0.5 2.0 (-0.6)
(Solar minimum using 365d smoothing:
November 17, 2019)
4.19
2019.12 70.8 68.6 1.6 1.8 (-0.2)
(ISN 13 months smoothed
solar minimum)
3.22
2023.01 182.4 176.6 144.4 113.3 (+6.6) 8.73
2023.02 167.2 163.2 111.3 117.8 (+3.5) 14.48
2023.03 157.2 155.6 123.3 121.1 (+3.3) 14.42
2023.04 145.4 146.4 97.6 122.9 (+1.8) 13.40
2023.05 155.6 159.2 137.4 124.2 (+1.3) 10.67
2023.06 161.7 166.8 160.5 125.3 (+1.1) 8.95
2023.07  176.4 182.2 160.0 124.6 (-0.7) 8.15
2023.08  153.7 157.6 114.8 124.3 (-0.3) 7.19
2023.09  154.4 156.0 134.2 124.0 (-0.3) 14.26
2023.10  142.8 141.9 99.4 124.8 (+0.8) 8.16
2023.11 153.5 150.2 105.4 127.9 (+3.1) 12.20
2023.12 151.1 146.4 114.2 129.5 (+1.6) 9.60
2024.01 164.6 159.3 126.0 131.1 (+1.6) 5.46
2024.02 172.5 168.3 123.0 136.9 (+5.8) 5.31
2024.03 154.4 152.9 103.7 141.4 (+4.5) 11.03
2024.04 161.3 162.6 137.0 144.4 (+3.1) 9.69
2024.05 187.7 191.9 172.1 (149.7 projected, +5.3) 23.56
(SC25 peak)
2024.06 184.3 190.2 164.1 (153.6 projected, +3.9) 10.24
2024.07 196.6 203.0 196.5  (156.5 projected, +2.9) 7.13
2024.08  246.1
(cycle peak)
252.2 215.5  (SC25 peak) (158.5 projected, +2.0) 15.96
2024.09 195.7 197.8 141.4 (161.2 projected, +2.7) 15.36
2024.10 221.0 219.6 166.3 (163.5 projected, +2.3) 18.99
2024.11 217.8 (1)   74.4 (2A) / 159.5 (2B) / 209.2 (2C) (161.8 projected, -1.7) (11.8)
2024.12       (158.7 projected, -3.1)  
2025.01       (154.4 projected, -4.3)  
2025.02       (147.6 projected, -6.8)  
2025.03       (142.8 projected, -4.8)  
2025.04       (139.8 projected, -3.0)  

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz and any corrections applied to that measurement.
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) Source: WDC-SILSO, Royal Observatory Of Belgium, Brussels

Solar cycles 24-25

Smoothed SF and sunspot numbers

Update on the progress of solar cycle 25 as of October 27, 2024

Sunspot activity in October 2024 increased over September and looks to be headed for an SSN near 160. The average solar flux for October will become the second highest for a month during SC25. The above plot now displays the peak in 365d smoothed sunspot numbers in mid October. ISN has a peak on October 15, NOAA SN on October 14 while both the 1K and 2K SDO SN peaked on October 16. Assuming that the average sunspot number from October 2024 until April 14, 2025 becomes 150, we would be looking at a 365 days smoothed sunspot maximum of 164.5 centered on October 15. Should the average sunspot number for that period become 160 we would get a peak near 169.7.

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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.