Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 25, 2024 at 05:25 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 active levels on November 24 under the influence of weak effects from CH1257. Solar wind speed at SOHO ranged between 397 and 468 km/sec, averaging 427 km/sec (+16 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 202.7 - decreasing 52.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 186.10. In comparison SC24 peaked on June 28, 2014 at 145.50 while SC23 peaked on February 23, 2002 at 198.15. Current SC25 peak: 186.14 on May 21, 2024). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.4). Three hour interval K indices: 22200124 (planetary), 12202323 (Boulder), 23200115 (Andenes).

The background x-ray flux is at the class C3 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 362) and in 13 active regions using 1K resolution (SN: 246) SDO/HMI images.

AR 13898 [S16W77] decayed slowly and quietly.
AR 13899 [S11W40] decayed slowly and quietly.
AR 13900 [N25W04] developed in the trailing spot section and decayed in the leading spot section. SWPC split off the trailing spot section into AR 13909.
AR 13901 [S07W18] decayed in the leading spot section while a few new spots emerged in the trailing spot section.
AR 13902 [S16E23] was quiet and stable.
AR 13903 [S11W61] decayed slowly and quietly.
AR 13905 [S09E38] developed several small magnetic delta configurations in the intermediate spot section. A major flare is possible.
AR 13906 [S16E48] has a magnetic delta configuration within a penumbra in the southeastern part of the spot group. A major flare is possible.
AR 13907 [S21E04] has polarity intermixing and may be capable of producing a minor M class flare.
AR 13908 [N14E66] decayed slowly and produced several flares.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10384 [S18W12] was quiet and stable.
S10396 [N01W10] was quiet and stable.
S10397 [N14E44] reemerged with tiny spots
New region S10402 [N24E07] was observed with tiny spots in an old plage area.

A large filament eruption in the southern hemisphere was observed after 02h UT on November 25. A partial halo CME was associated with this event.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.4 00:52   13906 GOES16  
C7.6 01:08   13906 GOES16  
C4.6 01:15 behind northeast limb   GOES16  
C2.5 02:47 behind southwest limb   GOES16  
C2.5 03:01   13908 GOES16  
C3.9 03:28   13908 GOES16  
C5.6 03:36   13906 GOES16  
C5.6 06:33   13906 GOES16  
C5.5 07:53 S17E52 13906 GOES16  
C5.7 10:19   13908 GOES16  
C5.7 10:44   13908 GOES16  
C4.9 11:19 behind northeast limb   GOES16  
C6.0 11:39   13906 GOES16  
C3.9 13:00   13906 GOES16  
C5.6 13:12 N12E75 13908 GOES16  
C4.5 15:17 behind northeast limb   GOES16  
C6.6 16:31 S15E52 13906 GOES16  
C2.8 17:29   13906 GOES16  
C2.7 17:57   13906 GOES16  
C2.9 18:33   13906 GOES16  
M1.1 20:22 N21E90   GOES16  
C4.2 20:53   13906 GOES16  
C2.8 22:!5 behind northeast limb   GOES16  

Coronal mass ejections (CMEs)

November 22-24: 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 negative polarity southern hemisphere coronal hole (CH1257) was Earth facing on November 19-20. A recurrent positive polarity northern hemisphere coronal hole (CH1258) will likely rotate across the central meridian on November 27.

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 to fair. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 25 due to effects from CH1257 and quiet on November 26-27.

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
13893 2024.11.12
2024.11.13
      S19W88        

location: S19W81

13900 2024.11.16
2024.11.18
  17 8 N22W22 0040   CRI

location: N25W04

SWPC split off the trailing spot section into AR 13909

13901 2024.11.17
2024.11.18
10 29 17 S07W16 0090 CAO CAI beta-gamma

area: 0240

location: S07W18

13898 2024.11.17
2024.11.17
3 4 2 S15W83 0010 BXO CRO

area: 0015

location: S16W77

13899 2024.11.17
2024.11.17
1 3 1 S11W41 0010 HSX HRX

location: S11W40

S10378 2024.11.18       S20W40            
S10379 2024.11.18       S17W14            
S10380 2024.11.18       N20W40            
S10382 2024.11.19       S04W37            
S10384 2024.11.19   9 4 S18W12 0030   BXO  
S10386 2024.11.19       S01W58            
13902 2024.11.20
2024.11.20
1 10 2 S16E22 0060 HSX CSO

location: S16E23

area: 0120

S10388 2024.11.20       N22W50          
S10390 2024.11.20       N27E16            
13903 2024.11.21
2024.11.21
5 15 6 S11W60 0030 DAO DRI

location: S11W61

area: 0070

13905 2024.11.21
2024.11.21
8 39 25 S09E40 0250 EKO EKI

beta-gamma-delta

location: S09E38

area: 1070

very low SWPC area and spot count

S10393 2024.11.21       S37W56            
S10394 2024.11.21       S19W36          
13906 2024.11.22
2024.11.22
15 48 30 S16E47 0500 EKC EKC beta-gamma-delta

location: S16E48

area: 1010

S10396 2024.11.22   3   N01W10 0006   AXX  
S10397 2024.11.22   4 2 N14E44 0010   AXX    
13907 2024.11.23
2024.11.23
11 27 14 S21E01 0025 CRO DRI beta-gamma

was AR S10398

location: S21E04

area: 0080

13908 2024.11.23
2024.11.23
6 6 3 N14E65 0040 BXO CRO location: N14E66
S10399 2024.11.23       N13E03          
S10400 2024.11.23       S05W23          
S10401 2024.11.23       N01E02          
13909 2024.11.24 4     N25W04 0010 BXO       see AR 13900
S10402 2024.11.24   8 2 N24E07 0015   BXO    
Total spot count: 64 222 116  
Sunspot number: 164 362 246  (total spot count + 10 * number of spotted regions)
Weighted SN: 107 270 162  (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): 180 199 197  

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
2023.03 157.2 155.6 123.3 121.1 (+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
2024.11 193.5 (1)   115.7 (2A) / 144.6 (2B) / 198.5 (2C)
ISN current month average: 150
(161.8 projected, -1.7) (10.1)
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 2024. 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.