Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 18, 2024 at 05:40 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 17. Solar wind speed at SOHO ranged between 347 and 428 km/sec, averaging 384 km/sec (-10 compared to the previous day). 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 20h UT on 2.8 GHz was 146.3 - decreasing 17.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 186.12. In comparison SC24 peaked on June 28, 2014 at 145.50 while SC23 peaked on February 23, 2002 at 198.15. Current SC25 peak: 186.12 on May 19, 2024). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.1). Three hour interval K indices: 13223111 (planetary), 03233221 (Boulder), 02113123(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 11 active regions using 2K resolution (SN: 188) and in 10 active regions using 1K resolution (SN: 137) SDO/HMI images.

AR 13889 [S09W67] decayed slowly producing mostly low level C flares. C1 flares: C1.7 @ 04:55, C1.4 @ 06:36, C1.3 @ 07:16, C1.7 @ 16:03, C1.4 @ 16:30, C1.4 @ 21:58, C1.3 @ 23:51 UT
AR 13893 [S19E10] decayed slowly and quietly.
AR 13894 [N23E05] decayed slowly and quietly.
New AR 13896 [N05W02] emerged on November 14 and was numbered by SWPC 3 days later as new flux emerged.
New AR 13897 [S11W46] emerged on November 16 and received its NOAA number the following day. C flares are possible. C1 flares: C1.4 @ 12:34, C1.4 @ 17:48 UT
New AR 13898 [S17E16] emerged early in the day trailing AR 13893. C1 flares: C1.6 @ 18:31 UT
New AR 13899 [S13E56] emerged with a few spots and has potential for further development.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10363 [S32W03] was quiet and stable.
S10368 [N25E28] was quiet and stable.
S10369 [N22E73] was mostly quiet and stable. C1 flares: C1.4 @ 09:44 UT
New region S10371 [S07E75] rotated into view with mostly mature spots. The trailing appears to have a small magnetic delta configuration. An M1.0 flare was recorded at 05:22 UT on November 18. C1 flares: C1.5 @ 00:22, C1.3 @ 12:56, C1.5 @ 15:27, C1.8 @ 19:43, C1.3 @ 22:19 UT

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.3 10:58   S10371 GOES16  
C4.6 11:37   13889 GOES16  
C2.0 23:13   13889 GOES16  

Coronal mass ejections (CMEs)

November 16-17: No obviously Earth directed CMEs were observed.
November 15: A filament eruption in the southeast quadrant late on Nov. 14 and early on Nov. 15 was associated with a partial halo CME. Components of this CME could reach Earth on November 18.

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) will likely rotate across the central meridian on November 18-20.

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.

Forecast

The geomagnetic field is expected to be quiet to active on Nov. 18-19 due to effects from CH1255. Components of the November 14/15 CME could reach Earth on November 18 and cause unsettled and active intervals that day and on November 19. Quiet to unsettled disturbance levels are likely on November 20-21

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
13891 2024.11.05
2024.11.11
      S15W84          

location: S16W77

13889 2024.11.06
2024.11.07
12 10 5 S09W71 0430 FKO FHO beta-gamma

area: 0580

location: S09W67

13892 2024.11.08
2024.11.11
      S11W57        

location: S12W53

13895 2024.11.11
2024.11.16
1     S03W49 0005 AXX     spotless
13893 2024.11.12
2024.11.13
1 1 1 S19E06 0030 HSX HSX

area: 0080

location: S19E10

13894 2024.11.13
2024.11.14
1 5 1 N21E01 0010 AXX CRO

location: N23E05

S10353 2024.11.13       N22W34            
S10355 2024.11.14       N07W27          
13896 2024.11.14
2024.11.17
5 11 8 N05W04 0050 CAO DAO location: N05W02

area: 0070

 
S10357 2024.11.14       S17E18            
S10358 2024.11.14       S12W27            
S10359 2024.11.14       S13E03            
S10362 2024.11.15       N07W28            
S10363 2024.11.15   2 1 S32W03 0002   AXX  
S10366 2024.11.16       S21E18          
13897 2024.11.16
2024.11.17
9 18 7 S12W47 0070 CAO DAO area: 0200

location: S11W46

S10368 2024.11.16   6   N25E28 0010   BXO  
S10369 2024.11.16   2 1 N22E73 0060   CAO  
S10370 2024.11.16       S01W03          
S10371 2024.11.17   7 5 S07E75 0400   DAC   beta-delta
13898 2024.11.17
2024.11.17
5 12 5 S15E19 0050 CAO DRI   was AR S10372

location: S17E16

13899 2024.11.17
2024.11.17
3 4 3 S13E60 0010 BXO CRO   was AR S10374

area: 0040

location: S13E56

Total spot count: 37 78 37  
Sunspot number: 117 188 137  (total spot count + 10 * number of spotted regions)
Weighted SN: 67 120 79  (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): 129 103 110  

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
2024.11 202.6 (1)   83.1 (2A) / 146.6 (2B) / 201.7 (2C) (161.8 projected, -1.7) (11.2)
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.