Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 20, 2024 at 06:10 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 19, weakly under the influence of effects from CH1255. Solar wind speed at SOHO ranged between 369 and 454 km/sec, averaging 404 km/sec (+30 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 157.2 - decreasing 28.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 186.14. 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: 7.5). Three hour interval K indices: 21223321 (planetary), 11224321 (Boulder), 31124442 (Andenes).

The background x-ray flux is at the class C1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 17 active regions using 2K resolution (SN: 302) and in 15 active regions using 1K resolution (SN: 214) SDO/HMI images.

AR 13889 [S11W85] rotated mostly out of view and was mostly quiet.
AR 13893 [S19W15] decayed slowly and quietly.
AR 13894 [N25W20] was quiet and stable.
AR 13896 [N06W30] developed slowly and quietly.
AR 13897 [S11W74] developed slowly becoming a compact spot group. C1 flares: C1.8 @ 14:23 UT
AR 13898 [S16W11] developed further and has a small magnetic delta configuration. A minor M class flare is possible.
AR 13899 [S12E27] was mostly quiet and stable.
AR 13900 [N22E47] decayed slowly and quietly.
AR 13901 [S07E51] decayed slightly as the magnetic delta weakened. M class flares are still possible. C1 flares: C1.9 @ 07:12 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10368 [N24E01] was quiet and stable.
S10375 [N23W49] developed slowly and quietly.
S10377 [S21W19] decayed slowly and quietly.
New region S10382 [S04E28] emerged with tiny spots in an old plage area.
New region S10383 [S06W39] emerged with tiny spots.
New region S10384 [S16E63] was observed with a tiny spot in an old plage area. C1 flares: C1.8 @ 11:10 UT
New region S10385 [S37W20] was observed with a tiny spot in an old plage area.
New region S10386 [S01E07] was observed with a tiny spot in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 02:27   13901 GOES16  
C2.4 02:47   13897 GOES16  
C2.0 03:12   13889 GOES16  
C2.7 03:53   13901 GOES16  
C2.6 04:26   13889 GOES16  
C2.1 05:25   13897 GOES16  
C2.1 05:36   13901 GOES16  
C2.0 08:26   13889 GOES16 simultaneous flare in AR 13898
C2.5 08:45   13897 GOES16  
C3.0 15:35   13897 GOES16  
C3.1 16:02   13901 GOES16  
C2.5 16:26   13899 GOES16  
C2.7 16:32   13901 GOES16  
C3.2 16:41   13898 GOES16  
C4.0 16:56   13901 GOES16  
C5.3 17:23   13889 GOES16  
C9.0 17:28 S05E56 13901 GOES16  
C7.9 18:34   13901 GOES16  
C7.0 21:28   13897 GOES16  
C3.1 22:40   13897 GOES16  

Coronal mass ejections (CMEs)

November 17-19: 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 positive polarity northern hemisphere coronal hole (CH1255) was Earth facing on November 14-15. A negative polarity southern hemisphere coronal hole (CH1256) rotated across the central meridian on November 18. A negative polarity southern hemisphere coronal hole (CH1257) will be Earth facing on November 19-20.

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 20 due to effects from CH1255. Effects from CH1256 and CH1257 could cause some unsettled and active intervals on November 21-23.

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
13889 2024.11.06
2024.11.07
  2 1 S11W85 0200   HAX  
13892 2024.11.08
2024.11.11
1     S11W88 0070 HSX      

location: S12W79

AR 13892 is spotless.
SWPC/USAF has moved the trailing spot of AR 13889 to this region, a major mistake

13895 2024.11.11
2024.11.16
      S03W79            
13893 2024.11.12
2024.11.13
1 6 1 S19W17 0050 HSX HAX

location: S19W15

13894 2024.11.13
2024.11.14
  2 1 N21W27 0004   BXO

location: N25W20

S10355 2024.11.14       N07W53            
13896 2024.11.14
2024.11.17
5 14 8 N06W31 0060 DAO DRI location: N06W30

area: 0100

 
S10357 2024.11.14       S17W08            
S10358 2024.11.14       S12W53            
S10359 2024.11.14       S13W23            
S10362 2024.11.15       N07W54            
S10363 2024.11.15       S32W29            
S10366 2024.11.16       S21W08            
13897 2024.11.16
2024.11.17
10 21 12 S10W75 0140 DAI DAC beta-gamma

area: 0500

location: S11W74

S10368 2024.11.16   5 2 N24E01 0015   BXO  
13900 2024.11.16
2024.11.18
1 5 1 N22E47 0030 CRO DSO

area: 0050

Incompatible SWPC classification and spot number

S10370 2024.11.16       S01W29            
13901 2024.11.17
2024.11.18
3 17 9 S08E51 0200 DAO DAC beta-delta

area: 0340

location: S07E51

13898 2024.11.17
2024.11.17
7 32 16 S17W11 0030 CRO DRI

beta-delta

area: 0110

location: S16W11

13899 2024.11.17
2024.11.17
1 11 3 S12E27 0030 HAX CAO area: 0050
S10375 2024.11.18   7 5 N23W49 0030   DRO  
S10377 2024.11.18   1 1 S21W19 0003   AXX  
S10378 2024.11.18       S20E25          
S10379 2024.11.18       S17E51          
S10380 2024.11.18       N20E25          
S10382 2024.11.19   3 1 S04E28 0010   AXX    
S10383 2024.11.19   3 2 S06W39 0010   CRO    
S10384 2024.11.19   1   S16E63 0002   AXX    
S10385 2024.11.19   1   S37W20 0002   AXX    
S10386 2024.11.19   1 1 S01E07 0004   AXX    
Total spot count: 29 132 64  
Sunspot number: 109 302 214  (total spot count + 10 * number of spotted regions)
Weighted SN: 65 174 106  (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): 120 166 171  

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) 18.99
2024.11 197.3 (1)   90.6 (2A) / 143.1 (2B) / 201.5 (2C) (161.8 projected, -1.7) (10.6)
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.