Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 24, 2024 at 09:50 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 23, weakly under the influence of effects from CH1257. Solar wind speed at SOHO ranged between 377 and 471 km/sec, averaging 411 km/sec (-5 compared to the previous day). 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 199.9 - decreasing 46.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 186.03. 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 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.8). Three hour interval K indices: 32223122 (planetary), 20223222 (Boulder), 32112234 (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 18 active regions using 2K resolution (SN: 398) and in 15 active regions using 1K resolution (SN: 252) SDO/HMI images.

AR 13893 [S19W68] was quiet and stable.
AR 13898 [S15W63] decayed slowly and produced several C flares.
AR 13899 [S12W26] was quiet and stable.
AR 13900 [N23E02] gained trailing spots and was mostly quiet.
AR 13901 [S07W04] developed slowly and was mostly quiet.
AR 13902 [S16E37] was quiet and stable.
AR 13903 [S11W48] decayed slowly and quietly.
AR 13905 [S09E52] gained area and has major flare potential.
AR 13906 [S16E61] developed and is a compact spot group with several small magnetic delta configurations. A major flare is possible.
New AR 13907 [S21E17] emerged with many tiny and small spots.
New AR 13908 [N14E78] rotated into view with small spots and produced several C flares and 1 M flare during the day.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10384 [S18E03] was quiet and stable.
S10388 [N22W37] was quiet and stable.
S10394 [S19W23] was quiet and stable.
S10396 [N02E05] was quiet and stable.
New region S10399 [N13E16] was observed with tiny spots in an old plage area.
New region S10400 [S05W10] emerged with a tiny spot.
New region S10401 [N01E15] emerged with a tiny spot.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.5 01:27   13905 GOES16  
C2.9 01:56   13901 GOES16  
C2.4 02:25   13905 GOES16  
C7.0 03:20   13905/13906 GOES16  
C3.0 03:38   13898 GOES16  
C2.3 07:24   13906 GOES16  
C2.1 07:55   13908 GOES16  
C4.0 08:37   13898 GOES16  
C3.4 08:46   13906 GOES16  
C2.7 08:59   13908 GOES16  
C2.1 10:22   13908 GOES16  
C2.3 10:47   13908 GOES16  
C3.1 11:47   13908 GOES16  
C2.5 12:06   13901 GOES16  
C3.1 12:16   13908 GOES16  
C3.2 13:07   13908 GOES16 simultaneous flare in AR 13898
C3.6 13:37 S15W65 13898 GOES16  
C2.6 14:20   13901 GOES16  
C4.8 15:48   13901 GOES16 simultaneous flare behind the southwest limb
M1.1/2N 16:07 S07E04 13901 GOES16  
C5.3 16:41   13906 GOES16  
C3.5 17:32   13908 GOES16  
M1.1 18:10   13908 GOES16 simultaneous flare in AR 13901
C5.4 19:20 S14W65 13898 GOES16  
C4.0 21:39   13908 GOES16  
C7.0 03:20   13906 GOES16  
C5.6/1F 22:58 S16E60 13906 GOES16  
C5.3 23:10   13906 GOES16  
C4.1 23:46   13906 GOES16  

Coronal mass ejections (CMEs)

November 20-22: 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. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 23 due to effects from CH1257 and quiet on November 24-25.

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
  1   S19W74 0001   AXX

location: S19W68

13894 2024.11.13
2024.11.14
      N21W84          

location: N26W74

13896 2024.11.14
2024.11.17
      N05W89         location: N05W85
S10368 2024.11.16       N24W51            
13900 2024.11.16
2024.11.18
2 10 8 N22W08 0010 BXO ERO

area: 0030

location: N23E02

13901 2024.11.17
2024.11.18
5 35 16 S07W07 0090 CAO DAI beta-gamma

area: 0400

location: S07W04

13898 2024.11.17
2024.11.17
4 10 4 S15W69 0010 CAO DRI

beta-gamma

area: 0050

location: S15W63

13899 2024.11.17
2024.11.17
1 13 3 S11W30 0010 HSX CAO area: 0030

loction: S12W26

S10378 2024.11.18       S20W27            
S10379 2024.11.18       S17W01            
S10380 2024.11.18       N20W27          
S10382 2024.11.19       S04W24            
S10384 2024.11.19   10 3 S18E03 0020   BXO  
S10386 2024.11.19       S01W45            
13902 2024.11.20
2024.11.20
1 8 2 S16E28 0060 HSX CSO

location: S16E37

area: 0130

SWPC location is way off

S10388 2024.11.20   7 3 N22W37 0020   CRO  
13904 2024.11.20
2024.11.21
8     S14W91 0050 CAO     rotated out of view
S10390 2024.11.20       N27E29            
13903 2024.11.21
2024.11.21
5 14 7 S11W45 0040 DAO DAO

location: S11W48

area: 0100

13905 2024.11.21
2024.11.21
8 26 17 S09E53 0120 ESO EKI

beta-gamma

location: S09E52

area: 0910

S10393 2024.11.21       S37W43            
S10394 2024.11.21   12 2 S19W23 0020   BXO  
13906 2024.11.22
2024.11.22
11 35 19 S16E59 0240 DAI DKC beta-gamma-delta

location: S16E61

area: 1040

S10396 2024.11.22   4 1 N02E05 0010   AXX  
S10397 2024.11.22       N12E57          
13907 2024.11.23
2024.11.23
11 21 12 S21E15 0025 CRO DRI   beta-gamma

was AR S10398

location: S21E17

area: 0060

13908 2024.11.23
2024.11.23
  7 4 N14E78 0050   CAO    
S10399 2024.11.23   3 1 N13E16 0006   BXO    
S10400 2024.11.23   1   S05W10 0002   AXX    
S10401 2024.11.23   1   N01E15 0001   AXX    
Total spot count: 56 218 102  
Sunspot number: 156 398 252  (total spot count + 10 * number of spotted regions)
Weighted SN: 99 275 159  (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): 172 219 202  

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
2024.11 193.1 (1)   110.2 (2A) / 143.7 (2B) / 200.4 (2C)
ISN current month average: 149
(161.8 projected, -1.7) (10.2)
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.