Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 8, 2024 at 07:35 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 quiet to unsettled on November 7. Solar wind speed at SOHO ranged between 383 and 465 km/sec, averaging 417 km/sec (-39 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 at the end of the day. A weak solar wind shock was observed at 14:24 UT at ACE, the arrival of the October 4 CME.

Solar flux density measured at 20h UT on 2.8 GHz was 239.2 - increasing 25.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 184.92. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 184.92 on May 9, 2024). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.0). Three hour interval K indices: 11221333 (planetary), 11331422 (Boulder), 21221345 (Andenes).

The background x-ray flux is at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 19 active regions using 2K resolution (SN: 496) and in 18 active regions using 1K resolution (SN: 365) SDO/HMI images.

AR 13878 [N15W61] decayed and was mostly quiet.
AR 13879 [N15W42] was quiet and stable.
AR 13880 [S14W37] reemerged with tiny spots.
AR 13881 [S10W56] decayed slowly and quietly.
AR 13883 [S06W07] decayed in the trailing spot section losing some spots. Flare activity decreased. Another major flare is possible as there are still magnetic delta configurations in the trailing spot section.
AR 13884 [S07E12] was quiet and stable.
AR 13886 [S05E28] decayed in the leading spot section while more spots developed in the trailing spot section. A small magnetic delta configuration formed in a trailing section penumbra.
AR 13887 [N15W84] decayed slowly and was mostly quiet.
New AR 13889 [S10E68] rotated into view on November 6 and was numbered the next day by SWPC. There's a small magnetic delta configuration within a trailing penumbra. Although the region has been less active over the last day compared to when it was at the southeast limb, a major flare is possible.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10300 [S03W22] was quiet and stable.
S10314 [S12E17] decayed slowly and quietly.
S10319 [N18W07] was quiet and stable.
S10323 [S08W26] was quiet and stable.
S10324 [S12E25] was mostly quiet and stable.
S10330 [S15E54] decayed slowly and quietly.
S10331 [S08E21] decayed in the trailing spot section.
S10336 [S14E00] was quiet and stable.
New region S10337 [S11E33] was split off from AR S10331 when it was evident that this was a bipolar spot group.
New region S10338 [N21E21] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
M2.5 01:27 S10E80 13889 GOES16  
C6.2 01:56   13889 GOES16  
C7.5 02:09 N16W66 13887 GOES16  
C4.2 02:40   13883 GOES16  
C4.4 03:00   13887 GOES16  
C3.7 03:28   13887 GOES16  
M2.5/1N 04:20   13883 GOES16  
C7.6 04:59   13883 GOES16  
C4.8 05:46   13883 GOES16  
C4.9 06:09   S10324 GOES16  
C7.1 07:14   S10331 GOES16 simultaneous flare in AR 13883
M1.3/1F 07:26 S09E06 13883 GOES16  
M1.6 07:43   13889 GOES16  
M2.7 07:54   13889 GOES16  
C7.9 08:29   13889 GOES16  
C4.4 08:51   13883 GOES16  
C4.6 09:09   13889 GOES16  
C4.3 09:29   13889 GOES16  
C4.0 09:53   13883 GOES16  
C4.4 10:03   13889 GOES16  
C4.7 10:51   13886 GOES16  
C5.7 11:18 S08E01 13883 GOES16  
M1.4 12:02 S09E76 13889 GOES16  
C3.5 13:33   13889 GOES16  
C4.4 14:41   13889 GOES16  
M2.3/1F 15:06 S07W00 13883 GOES16  
C4.4 16:32   13883 GOES16  
C3.3 17:51   13886 GOES16  
C4.7 18:25   13878 GOES16  
C5.5 18:45   13889 GOES16  
C4.4 20:09   13889 GOES16  
C6.7 21:34   13883 GOES16  
C3.9 21:56   13883 GOES16  
C3.8 23:46   S10331 GOES16  

Coronal mass ejections (CMEs)

November 5-7: 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 trans equatorial negative polarity coronal hole (CH1253) rotated acrosss the central meridian on November 4-5. A recurrent northern hemisphere positive polarity coronal hole (CH1254) could become Earth facing on November 8-11. CH1254 has expanded a lot since the previous previous rotation.

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 to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 8-9 with a chance of active intervals due to effects from CH1253. Quiet conditions are likely on November 10. November 11-13 could see quiet to active levels as a high speed stream associated with CH1254 becomes the dominant solar wind source.

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
13878 2024.10.26
2024.10.27
3 9 5 N16W66 0150 HAX CAO

location: N15W64

13887 2024.10.27
2024.11.06
4 4 3 N16W84 0130 DAO CAO  
13879 2024.10.28
2024.10.29
3 17 7 N15W44 0450 CHO CHO

area: 0950

location: N15W42

13880 2024.10.29
2024.10.31
  2 1 S14W40 0003   BXO  

location: S14W37

S10300 2024.10.30   6 2 S03W22        
13881 2024.10.30
2024.11.01
4 11 7 S09W57 0130 DAO DAO

area: 0160

location: S10W56

S10307 2024.11.01       N08W53            
13883 2024.11.01
2024.11.02
23 57 39 S07W07 0400 FKC FKC beta-gamma-delta

area: 0720

S10309 2024.11.01       S24W45            
13884 2024.11.02
2024.11.02
1 10 6 S07E11 0040 HSX CAO

area: 0070

S10314 2024.11.02   9 5 S12E17 0020   BXO  
S10316 2024.11.02       N18W26            
13886 2024.11.03
2024.11.03
36 61 42 S08E23 0370 FKI EAI

beta-delta

location: S04E40

area: 0420

SWPC includes ARs S10331 and S10324 in this spot group

S10319 2024.11.03   5 2 N18W07 0010   BXO  
S10320 2024.11.03       N16E11            
S10321 2024.11.03       N31W57            
S10322 2024.11.04       N03W30            
S10323 2024.11.04   13 2 S08W26 0025   BXO  
S10324 2024.11.04   30 19 S12E25 0140   DRI  
S10325 2024.11.04       S14W13            
S10326 2024.11.04       S34W53            
13888 2024.11.05
2024.11.06
      N04W66          
S10329 2024.11.05       N15W28            
S10330 2024.11.05   6 2 S15E54 0015   HRX  
S10331 2024.11.05   21 16 S08E21 0180   DAI  
S10332 2024.11.05       S33W45            
13889 2024.11.06
2024.11.07
10 32 23 S10E66 0250 EKC EKC beta-gamma-delta

location: S10E68

area: 0750

S10334 2024.11.06       N12W05          
S10335 2024.11.06       N19W53          
S10336 2024.11.06   4 2 S14E00 0008   AXX  
S10337 2024.11.07   6 2 S11E33 0010   BXO    
S10338 2024.11.07   3   N21E21 0005   AXX    
Total spot count: 84 306 185  
Sunspot number: 164 496 365  (total spot count + 10 * number of spotted regions)
Weighted SN: 144 372 251  (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): 180 273 292  

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) 19.0
2024.11 247.9 (1)   44.4 (2A) / 190.1 (2B) / 210.9 (2C) (161.8 projected, -1.7) (9.8)
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.