Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 4, 2024 at 07:05 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 (October 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 active on November 3. Solar wind speed at SOHO ranged between 422 and 558 km/sec, averaging 466 km/sec (+6 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 0.9 pfu at the end of the day, slowly decreasing towards background levels.

Solar flux density measured at 20h UT on 2.8 GHz was 240.6 - decreasing 2.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 183.85. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 183.85 on May 5, 2024). The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.5). Three hour interval K indices: 30110334 (planetary), 21012323 (Boulder), 31000245 (Andenes).

The background x-ray flux is at the class C4 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 20 active regions using 2K resolution (SN: 460) and in 14 active regions using 1K resolution (SN: 257) SDO/HMI images.

AR 13869 [S18W72] decayed slowly and was mostly quiet.
AR 13873 [S16W62] decayed slowly and quietly.
AR 13875 [N29W74] decayed slowly and quietly.
AR 13877 [S17W40] decayed and had only a tiny spot left at the end of the day.
AR 13878 [N16W12] decayed slowly losing the largest magnetic delta configuration.
AR 13879 [N14E09] was quiet and stable.
AR 13880 [S13E18] decayed slowly and quietly.
AR 13881 [S09W02] developed slowly and produced several C flares. A magnetic delta configuration formed in the intermediate spot section.
AR 13883 [S06E48] developed quickly and merged with AR S10313. Several magnetic delta configurations formed and the region is very unstable. Several M flares have been recorded early on Nov.4 and there is a chance of a major flare.
AR 13884 [S07E65] was mostly quiet and stable.
New AR 13885 [S10W44] emerged on November 2 and gained many spots as more flux emerged.
New AR 13886 [S05E78] rotated into view and has M class flare potential. The southernmost spot could be split off into a separate region.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10303 [S11W82] rotated partly out of view.
S10304 [S12W16] was quiet and stable.
S10307 [N08W01] was quiet and stable.
S10309 [S24E07] was quiet and stable.
S10314 [S13E69] was quiet and stable.
New region S10319 [N17E39] was observed with tiny spots in an old plage area.
New region S10320 [N16E63] emerged with a tiny spot.
New region S10321 [N31W05] emerged with a tiny spot.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.4 02:48   13886 GOES16  
M1.1 03:11 S04E90 13886 GOES16 simultaneous flare in AR 13869
C7.2 03:46 S09E10 13881 GOES16  
C3.6 05:09   13884 GOES16  
C5.0 05:35   13886 GOES16 simultaneous flare in AR 13878
C4.9 06:14   13881 GOES16 simultaneous flare in AR 13886
C8.1 06:36 S10E09 13881 GOES16 simultaneous flare in AR S10303
C4.2 07:24   13881 GOES16  
C5.1 07:35   13878 GOES16  
C5.3 08:10 S09E10 13881 GOES16  
C4.9 08:33   13883 GOES16  
M1.1/1F 08:49   13878 GOES16  
C6.3 09:57   13878 GOES16 simultaneous flares in ARs 13883 and 13886
C5.5 10:51 southwest limb   GOES16 simultaneous flares in ARs 13883 and 13886
C4.9 11:45   13886 GOES16 simultaneous flare in AR S10303
C5.8 12:16 N16W03 13878 GOES16  
C5.6 12:47   13881 GOES16 simultaneous flare in AR 13878
C6.3 12:59   13883 GOES16 simultaneous flare in AR S10303
C4.0 13:21   13886 GOES16  
C7.6 13:30 S08E52 13883 GOES16  
C8.2 15:11   13883 GOES16  
M1.1 15:18   13881 GOES16  
M1.4 15:24   13869 GOES16  
C8.5 15:37   13883 GOES16  
C7.6 16:06   13886 GOES16 simultaneous flare in AR 13883
C4.6 16:56   S10303 GOES16  
C4.8 17:25   13878 GOES16  
C5.3 17:46   13883 GOES16  
M1.3 17:53   13883 GOES16  
C4.3 18:49   13883 GOES16  
C4.2 19:18   13875 GOES16 simultaneous flare in AR 13886
C4.3 20:06   13886 GOES16 simultaneous flare in AR 13883
C6.8 20:30   13875 GOES16 simultaneous flare in AR 13886
C8.9 20:42   13875 GOES16  
C6.8 20:55   13881 GOES16 simultaneous flare in AR 13886
C5.9 21:07   13886 GOES16  
C4.4 21:50   13878 GOES16  
C4.6 22:30   13883 GOES16  
C5.0 22:41   13883 GOES16  
C5.2 22:54   13883 GOES16  
C5.1 23:20   13883 GOES16  
C6.9 23:25   S10303 GOES16  
C5.8 23:47   13885 GOES16  

Coronal mass ejections (CMEs)

November 1-3: 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 positive polarity trans equatorial coronal hole (CH1252) was Earth facing on October 31 - November 1.

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 very poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 4-5 due to effects from CH1252 and quiet on November 6.

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
13869 2024.10.22
2024.10.23
10 10 6 S18W74 0210 DAI EAO

location: S18W72

area: 0280

13875 2024.10.23
2024.10.24
6 3 2 N28W85 0110 ESO HAX

location: N29W74

SWPC location is way off

13872 2024.10.23
2024.10.24
4     S16W62 0130 HAX      

merged with AR 13869 on 2024.10.31
SWPC includes the leader spot of AR 13873

13871 2024.10.24 2     S09W89 0180 DAO       was part of AR 13869, see AR S10303
13873 2024.10.24
2024.10.24
2 16 5 S10W56 0020 HAX DAO

location: S16W62

area: 0190

SWPC has interpreted the leader spot as AR 13872

S10278 2024.10.24       S22W54            
13876 2024.10.25
2024.10.25
2     S04W90 0120 DAO     rotated out of view
S10284 2024.10.25       S15W47            
13877 2024.10.25
2024.10.27
  1   S17W46 0001   AXX

location: S17W40

13878 2024.10.26
2024.10.27
18 56 22 N16W16 0320 EKO EAI beta-gamma

location: N16W12

S10292 2024.10.27       N17W30          
13879 2024.10.28
2024.10.29
1 30 10 N15E10 0500 HHX CHO

area: 0880

location: N14E09

S10295 2024.10.28       N11W56            
S10296 2024.10.28       S01W43            
S10297 2024.10.29       S12W34            
13880 2024.10.29
2024.10.31
  9   S14E16 0015   BXO

location: S13E18

S10299 2024.10.30       S14W28          
S10300 2024.10.30       S08E26          
13881 2024.10.30
2024.11.01
15 19 14 S09W01 0240 DAI EAI beta-gamma-delta

area: 0470

S10303 2024.10.31   2 1 S11W82 0130   CAO

SWPC reassigned AR 13871 to this spot group on 2024.11.01

S10304 2024.10.31   2   S12W16 0004   AXX  
S10305 2024.10.31       S16W35            
13882 2024.11.01
2024.11.02
      N23W69          
S10307 2024.11.01   9   N08W01 0010   AXX  
13883 2024.11.01
2024.11.02
20 54 30 S06E51 0160 EAI EAC beta-gamma-delta

area: 0430

location: S06E48

S10309 2024.11.01   7 2 S24E07 0012   BXO  
S10310 2024.11.01       S29W30            
13884 2024.11.02
2024.11.02
2 4 3 S06E65 0060 CSO DSO

location: S07E65

area: 0110

13885 2024.11.02
2024.11.03
6 20 13 S10W43 0050 DRO DRI beta-gamma

area: 0080

S10313 2024.11.02       S04E55         merged with AR 13883 on 2024.11.03
S10314 2024.11.02   4 2 S13E69 0020   CRO  
S10315 2024.11.02       N27W20          
S10316 2024.11.02       N18E26          
13886 2024.11.03
2024.11.03
2 10 6 S05E76 0090 DAO DKO   was AR S10318

location: S05E78

area: 0570

S10319 2024.11.03   2 1 N17E39 0005   AXX    
S10320 2024.11.03   1   N16E63 0001   AXX    
S10321 2024.11.03   1   N31W05 0002   AXX    
Total spot count: 90 260 117  
Sunspot number: 220 460 257  (total spot count + 10 * number of spotted regions)
Weighted SN: 161 326 183  (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): 242 253 206  

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
2023.11 153.5 150.2 105.4 127.8 (+3.0) 12.20
2023.12 151.1 146.4 114.2 129.4 (+1.6) 9.60
2024.01 164.6 159.3 126.0 131.1 (+1.7) 5.46
2024.02 172.5 168.3 123.0 136.8 (+5.7) 5.31
2024.03 154.4 152.9 103.7 141.3 (+4.5) 11.03
2024.04 161.3 162.6 136.5 144.4 (+3.1) 9.69
2024.05 187.7 191.9 171.7 (149.6 projected, +5.2) 23.56
(SC25 peak)
2024.06 184.3 190.2 164.2 (153.5 projected, +3.9) 10.24
2024.07 196.6 203.0 196.5  (156.4 projected, +2.9) 7.13
2024.08  246.1
(cycle peak)
252.2 215.5  (SC25 peak) (158.4 projected, +2.0) 15.96
2024.09 195.7 197.8 141.4 (161.1 projected, +2.7) 15.36
2024.10 221.0 219.6 166.3 (163.4 projected, +2.3) 19.0
2024.11 249.1 (1)   22.4 (2A) / 224 (2B) / 204.2 (2C) (161.8 projected, -1.6) (8.7)
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.