Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 21, 2024 at 04:30 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 20, weakly under the influence of effects from CH1255. Solar wind speed at SOHO ranged between 343 and 458 km/sec, averaging 390 km/sec (-14 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 18h UT on 2.8 GHz was 147.2 - decreasing 49.6 over the previous solar rotation. The measurement at 20h UT was flare enhanced and therefore replaced by the 18h UT measurement. (Centered 1 year average SF at 1 AU - 183 days ago: 186.08. 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 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.0). Three hour interval K indices: 03322111 (planetary), 02323222 (Boulder), 02222132 (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 16 active regions using 2K resolution (SN: 278) and in 12 active regions using 1K resolution (SN: 171) SDO/HMI images.

AR 13893 [S18W29] decayed slowly and quietly.
AR 13896 [N05W43] was mostly quiet and stable.
AR 13897 [S12W86] rotated mostly out of view and was the most active region during the day. C1 flares: C1.8 @ 02:56, C1.8 @ 04:52 UT
AR 13898 [S15W25] decayed slowly and was mostly quiet. C1 flares: C1.7 @ 03:28, C1.8 @ 04:21 UT
AR 13899 [S12E13] was mostly quiet and stable.
AR 13900 [N22E36] was quiet and stable.
AR 13901 [S07E37] lost the magnetic delta configuration and was mostly quiet.
New AR 13902 [S16E75] rotated into view with a mature spot.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10368 [N25W12] was quiet and stable.
S10375 [N22W63] decayed slowly and quietly.
S10383 [S06W53] was quiet and stable.
S10384 [S16E52] was quiet and stable.
S10385 [S31W43] was quiet and stable.
New region S10388 [N21E00] emerged with a few spots.
New region S10389 [S13W49] emerged with a few spots.
New region S10390 [N27E68] was observed with a tiny spot in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.2 03:11   13897 GOES16  
C2.7 03:58   13901 GOES16  
C4.2 05:30   13897 GOES16  
C3.5 06:32   13898 GOES16  
C2.1 08:00   13898 GOES16  
C3.0 08:55   13897 GOES16  
C2.1 09:53   13901 GOES16  
C2.4 11:15   13901 GOES16  
C3.7 12:26   13901 GOES16  
C2.0 14:43   13901 GOES16  
C2.4 15:36   13897 GOES16  
C2.3 17:02   13897 GOES16  
C2.4 17:52   13897 GOES18  
C2.0 18:16   13897 GOES18  
C3.0 18:37   13897 GOES18  
M1.1 19:48   13897 GOES16 LDE
C3.9 23:01   13897 GOES16 LDE

Coronal mass ejections (CMEs)

November 18-20: 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 negative polarity southern hemisphere coronal hole (CH1256) rotated across the central meridian on November 18. A recurrent negative polarity southern hemisphere coronal hole (CH1257) was 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 21-23 due to effects from CH1256 and CH1257.

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 3 1 S19W31 0020 HRX HAX

location: S18W29

13894 2024.11.13
2024.11.14
      N21W41        

location: N25W33

13896 2024.11.14
2024.11.17
4 17 10 N05W46 0060 DAO DRI location: N05W43

area: 0100

S10357 2024.11.14       S17W21            
S10359 2024.11.14       S13W36            
S10363 2024.11.15       S32W42            
S10366 2024.11.16       S21W21            
13897 2024.11.16
2024.11.17
6 3 2 S12W90 0220 DAO DAO

location: S12W86

S10368 2024.11.16   2   N24W12 0003   BXO  
13900 2024.11.16
2024.11.18
1 8 3 N22E34 0020 HAX HAX

area: 0040

location: N22E36

S10370 2024.11.16       S01W42            
13901 2024.11.17
2024.11.18
10 28 11 S07E35 0180 DAO CSI beta-gamma

area: 0350

location: S07E37

13898 2024.11.17
2024.11.17
8 26 13 S16W27 0050 CAO DRI

area: 0140

location: S15W25

13899 2024.11.17
2024.11.17
1 8 3 S13E12 0030 HSX CRO area: 0040
S10375 2024.11.18   3 2 N22W63 0010   BXO  
S10377 2024.11.18       S21W32          
S10378 2024.11.18       S20E12            
S10379 2024.11.18       S17E38            
S10380 2024.11.18       N20E12            
S10382 2024.11.19       S04E15          
S10383 2024.11.19   4 2 S06W53 0015   CRO  
S10384 2024.11.19   5   S16E52 0010   BXO  
S10385 2024.11.19   1   S31W43 0002   AXX  
S10386 2024.11.19       S01W06          
13902 2024.11.20
2024.11.20
2 1 1 S17E70 0070 CSO HSX   was AR S10387

location: S16E75

area: 0100

S10388 2024.11.20   5 2 N21E00 0030   DRO    
S10389 2024.11.20   3 1 S13W49 0013   CRO    
S10390 2024.11.20   1   N27E68 0001   AXX    
Total spot count: 33 118 51  
Sunspot number: 113 278 171  (total spot count + 10 * number of spotted regions)
Weighted SN: 71 161 94  (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): 124 153 137  

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
2024.11 194.8 (1)   94.4 (2A) / 141.6 (2B) / 199.8 (2C) (161.8 projected, -1.7) (10.4)
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.