Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 19, 2024 at 05:20 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 levels on November 18. Solar wind speed at SOHO ranged between 332 and 434 km/sec, averaging 374 km/sec (-10 compared to the previous day). An increase in solar wind speed, density and temperature was observed after noon, possibly the arrival of effects related to CH1255. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. The above 10 MeV proton flux was at background levels all day.

Solar flux density measured at 18h UT on 2.8 GHz was 147.4 - decreasing 28.7 over the previous solar rotation. The measurement at 20h UT was flare enhanced and will therefore be replaced by the 18h UT measurement. (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 20, 2024). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.5). Three hour interval K indices: 22000111 (planetary), 12002321 (Boulder), 31000133 (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 16 active regions using 2K resolution (SN: 271) and in 13 active regions using 1K resolution (SN: 182) SDO/HMI images.

AR 13889 [S09W80] produced several C flares as it rotated to the southwest limb. C1 flares: C1.5 @ 01:55, C1.8 @ 03:35, C1.6 @ 06:39, C1.9 @ 14:47 UT
AR 13893 [S19W02] gained a few spots and was quiet.
AR 13894 [N24W11] decayed slowly and quietly.
AR 13896 [N06W17] decayed slowly and quietly.
AR 13897 [S11W60] gained spots and produced several flares including 2 M flares.
AR 13898 [S16E02] gained tiny and small spots and was mostly quiet.
AR 13899 [S12E41] was quiet and stable.
New AR 13900 [N22E60] rotated into view on November 16 and was numbered by SWPC 2 days later.
New AR 13901 [S07E64] rotated into view on November 17 and was assigned its NOAA number the following day. The region was very active due to a magnetic delta in a trailing penumbra. Activity decreased after the long duration M2 event.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10368 [N24E14] was quiet and stable.
New region S10375 [N22W36] emerged with tiny spots.
New region S10376 [N19W74] emerged with a tiny spot.
New region S10377 [S21W06] emerged to the southwest of AR 13893 with a few spots.
New region S10378 [S16E02] emerged with tiny spots.
New region S10379 [S17E64] emerged with a tiny spot.
New region S10380 [N20E38] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.2 01:14   13889 GOES16  
C4.5 02:07   13889 GOES16  
C3.2 02:32   13897 GOES16  
C2.3 04:09   13900 GOES16  
C3.8 04:53   13889 GOES16  
M1.0 05:22   13901 GOES16  
C2.4 05:55   13889 GOES16  
C2.8 05:59   13901 GOES16  
C2.9 06:59   13901 GOES16  
C3.8 07:20   13901 GOES16  
M1.7 07:32 S07E76 13901 GOES16  
M1.2/1N 07:57 S07E76 13901 GOES16  
C6.0 08:04   13901 GOES16  
C4.8 08:15   13889 GOES16  
C3.0 08:33   13889 GOES16  
C2.4 08:57   13901 GOES16  
C2.2 10:30   13901 GOES16  
M2.5 10:58   13901 GOES16  
M1.6 11:12   13897 GOES16  
M1.5 11:27   13897 GOES16 CME, moderate type II radio sweep
C6.9 12:35   13901 GOES16  
C7.0 12:44   13889 GOES16  
M3.7 12:53   13901 GOES16  
C4.3 13:29 behind southeast limb   GOES16  
C2.2 14:21   13901 GOES16  
C4.3 15:39   13901 GOES16  
C5.5 17:06   13889 GOES16  
M1.8 17:49   13901 GOES16  
C6.6 18:04   13901 GOES16  
M2.0 19:15 S09E72 13901 GOES16 LDE, weak type II radio sweep
C7.7 20:18   13889 GOES16  
C6.8 20:45   13889 GOES16  
M1.1 20:51   13901 GOES16  
C3.7 21:27   13897 GOES16  
C3.7 21:37   13897 GOES16  
C4.3 22:30   13897 GOES16  
C3.2 23:13   13889 GOES16  
C3.1 23:29   13901 GOES16  
M1.0 00:00   13889 GOES16  

Coronal mass ejections (CMEs)

November 16-18: 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 likely become 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 19 due to effects from CH1255. Quiet levels are likely on November 2021. 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
7 9 5 S09W81 0320 FKO FSO  
13892 2024.11.08
2024.11.11
      S11W72          

location: S12W66

13895 2024.11.11
2024.11.16
      S03W64            
13893 2024.11.12
2024.11.13
1 8 4 S19W05 0030 HSX HAX

area: 0060

location: S19W02

13894 2024.11.13
2024.11.14
  2   N21W13 0004   AXX

location: N24W11

S10353 2024.11.13       N22W47            
S10355 2024.11.14       N07W40            
13896 2024.11.14
2024.11.17
5 14 4 N05W19 0050 CAO DRO location: N06W17

area: 0070

 
S10357 2024.11.14       S17E05            
S10358 2024.11.14       S12W40            
S10359 2024.11.14       S13W10            
S10362 2024.11.15       N07W41            
S10363 2024.11.15       S32W16          
S10366 2024.11.16       S21E05            
13897 2024.11.16
2024.11.17
10 23 11 S12W62 0080 DAO DAI area: 0200

location: S11W60

S10368 2024.11.16   4   N24E14 0005   BXO  
13900 2024.11.16
2024.11.18
2 3 2 N24E62 0030 CSO DSO location: N22E60

area: 0060

S10370 2024.11.16       S01W16            
13901 2024.11.17
2024.11.18
5 11 5 S07E63 0180 DAI DAC beta-delta

area: 0350

13898 2024.11.17
2024.11.17
4 16 9 S16E02 0010 BXO DRI

area: 0080

13899 2024.11.17
2024.11.17
4 7 4 S13E43 0030 CAO CRO area: 0060

location: S12E41

S10375 2024.11.18   2 2 N22W36 0006   AXX    
S10376 2024.11.18   1   N19W74 0002   AXX    
S10377 2024.11.18   4 3 S21W06 0015   CRO    
S10378 2024.11.18   4 1 S20E38 0010   BXO    
S10379 2024.11.18   1 1 S17E64 0003   AXX    
S10380 2024.11.18   2 1 N20E38 0005   AXX    
Total spot count: 38 111 52  
Sunspot number: 118 271 182  (total spot count + 10 * number of spotted regions)
Weighted SN: 78 148 89  (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): 130 149 146  

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
2024.11 199.5 (1)   87.0 (2A) / 145.0 (2B) / 201.1 (2C) (161.8 projected, -1.7) (10.8)
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 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.