Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 26, 2024 at 04:55 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 25 under the influence of weak effects from CH1257. Solar wind speed at SOHO ranged between 383 and 472 km/sec. The high latitude magnetometer at Andenes recorded quiet to active 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 220.4 - decreasing 45.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 186.21. In comparison SC24 peaked on June 28, 2014 at 145.50 while SC23 peaked on February 23, 2002 at 198.15. Current SC25 peak: 186.21 on May 27, 2024). The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.3). Three hour interval K indices: 32223322 (planetary), 32233333 (Boulder), 44103433 (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 19 active regions using 2K resolution (SN: 440) and in 15 active regions using 1K resolution (SN: 274) SDO/HMI images.

AR 13899 [S11W53] decayed slowly and quietly.
AR 13900 [N25W20] decayed slowly and quietly.
AR 13901 [S07W32] decayed losing spots and area. The region was the source of an M1 flare at 20:54 UT. The flare triggered a filament eruption and a partial halo CME was observed.
AR 13902 [S15E09] was quiet and stable.
AR 13903 [S12W74] decayed quickly and was quiet.
AR 13905 [S09E25] produced C and M flares and has major flare potential on its own and in conjunction with AR 13906. The large penumbrae decreased in area.
AR 13906 [S16E35] displayed fragmentation of the major penumbrae and some loss of area. The region still has multiple small magnetic delta configurations. A major flare is possible.
AR 13907 [S21W10] has many small and tiny spots. A weak magnetic delta has formed and there is a chance of a minor M class flare.
AR 13908 [N14E52] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10384 [S15W19] was quiet and stable.
S10396 [N02W21] was quiet and stable.
S10397 [N16E31] was quiet and stable.
S10402 [N24W02] was quiet and stable.
New region S10403 [S12W41] emerged with tiny spots.
New region S10404 [N17E82] rotated into view with a large trailing spot in a reversed polarity configuration. The leading spot section appears to have polarity intermixing. Further major flares are possible in conjunction with AR S10405.
New region S10405 [N20E81] rotated into view with two small opposite polarity spots, apparently in a tight magnetic delta. These spots seem to be separate from AR S10404.
New region S10406 [S08E42] emerged with a tiny spot.
New region S10407 [S20E19] emerged with tiny spots.
New region S10408 [S19W72] emerged with a tiny spot.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.4 00:09   13906 GOES16  
C8.4 00:29   13906 GOES16  
C2.8 01:15   13905 GOES16  
C4.9 01:47   13906 GOES16  
M1.1 01:59   13906 GOES16  
C5.4 02:38   13906 GOES16  
C4.1 03:01   13901 GOES16  
C7.7 03:36   13906 GOES16 simultaneous flare in AR 13898
M1.8 04:53   13906 GOES16  
C3.0 06:26   S10404 GOES16  
M9.4 07:42   S10405 GOES16  
M1.8 08:32   13905 GOES16  
C7.5 09:26   13906 GOES16  
C3.9 10:11   13906 GOES16  
C3.7 10:26   13906 GOES16  
C3.8 10:34   13905 GOES16  
C5.4 10:47   13906 GOES16  
M2.0 12:12 S12E40 13906 GOES16 simultaneous flare in AR 13905
C4.5 14:35   S10405 GOES16  
C4.7 15:16   13905 GOES16  
C5.8 15:59   13906 GOES16  
M1.0 16:35   13905+13906 GOES16  
M1.5 17:07   S10405 GOES16  
C9.1 17:31   13906 GOES16  
C7.7 18:02   13906 GOES16  
C4.9 19:03   13906 GOES16  
C5.2 19:16   13906 GOES16  
C4.7 20:05 S06E30 13905 GOES16  
M1.9/2F 20:54 S09W25 13901 GOES16 CME, moderate type II radio sweep
M1.1 21:42   13906 GOES16  
M1.1 21:52   13898 GOES16  
C7.6 22:21   13906 GOES16  
C4.5 23:56   13898 GOES16  

Coronal mass ejections (CMEs)

November 23-24: No obviously Earth directed CMEs were observed.
November 25: A large filament eruption in the southern hemisphere was observed after 02h UT. A partial halo CME was associated with this event, and there is a slight chance components of this CME could reach Earth on November 28. Another filament eruption occurred in the southwest quadrant after an M1 flare in AR 13901 late in the day. There was considerable coronal dimming, however, it is still uncertain if the CME observed afterwards in LASCO imagery will reach Earth.

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
13900 2024.11.16
2024.11.18
  18 7 N22W36 0030   BXI

location: N25W20

SWPC split off the trailing spot section into AR 13909 on 2024.11.24

13901 2024.11.17
2024.11.18
6 12 6 S08W31 0080 CAO CAO beta-gamma

area: 0180

location: S07W32

13899 2024.11.17
2024.11.17
1 2 1 S10W55 0010 AXX HRX

location: S11W53

S10378 2024.11.18       S20W53            
S10379 2024.11.18       S17W27            
S10380 2024.11.18       N20W53            
S10382 2024.11.19       S04W50            
S10384 2024.11.19   8 1 S15W19 0015   BXO  
13902 2024.11.20
2024.11.20
1 7 1 S18E08 0060 HSX CSO

location: S15E09

area: 0100

S10390 2024.11.20       N27E03            
13903 2024.11.21
2024.11.21
4 8 4 S10W74 0030 DAO DRI

location: S12W74

13905 2024.11.21
2024.11.21
15 42 24 S10E26 0330 EKI EKC

beta-gamma-delta

location: S09E25

area: 0830

S10394 2024.11.21       S19W49            
13906 2024.11.22
2024.11.22
16 71 46 S17E33 0550 EKC EKC beta-gamma-delta

location: S16E35

area: 0860

S10396 2024.11.22   3   N02W21 0006   AXX  
S10397 2024.11.22   6   N16E31 0012   AXX  
13907 2024.11.23
2024.11.23
4 38 19 S21W13 0030 CRO DRI beta-gamma-delta

location: S21W10

area: 0110

13908 2024.11.23
2024.11.23
1 8 3 N13E54 0010 AXX CRO location: N14E52

area: 0020

S10399 2024.11.23       N13W10            
S10400 2024.11.23       S05W36            
S10401 2024.11.23       N01W11            
13909 2024.11.24 2     N25W18 0010 BXO       see AR 13900
S10402 2024.11.24   6 2 N24W02 0020   BXO  
S10403 2024.11.25   6 3 S12W41 0012   BXO    
S10404 2024.11.25   5 3 N17E82 0670   DKO    
S10405 2024.11.25   2 2 N20E80 0020   DRO    
S10406 2024.11.25   1   S08E42 0001   AXX    
S10407 2024.11.25   6 2 S20E19 0012   BXO    
S10408 2024.11.25   1   S19W72 0002   AXX    
Total spot count: 50 250 124  
Sunspot number: 140 440 274  (total spot count + 10 * number of spotted regions)
Weighted SN: 88 305 179  (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): 154 242 219  

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
2024.11 194.6 (1)   120.3 (2A) / 144.4 (2B) / 196.6 (2C)
ISN current month average: 151
(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.