Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 26, 2023 at 10:15 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 5, 2023)
Solar cycle Solar cycles 23-25 (November 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (November 1, 2023) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (July 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (November 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (November 1, 2023) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (November 26, 2023) 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

Recent activity

The geomagnetic field was quiet to major storm on November 25 due to CME effects. A solar wind shock was observed at 08:00 UT at SOHO. Solar wind speed at SOHO ranged between 463 and 636 km/sec. The high latitude magnetometer at Andenes recorded active to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 176.4 - increasing 41.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 157.32. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 37 (STAR Ap - based on the mean of three hour interval ap indices: 36.4). Three hour interval K indices: 33455564 (planetary), 23545543 (Boulder), 54455655 (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 15 active regions using 2K resolution (SN: 317) and in 14 active regions using 1K resolution (SN: 231) SDO/HMI images.

Region 13489 [S14W35] decayed slowly and quietly.
Region 13491 [N10W08] decayed slowly and quietly.
Region 13492 [N18W04] decayed further and was mostly quiet. C1 flares: C1.6 @ 03:28 UT
Region 13493 [S12E06] was mostly quiet and stable.
Region 13494 [S17E11] was mostly quiet and stable.
Region 13499 [S17W23] was mostly quiet and stable. C1 flares: C1.5 @ 08:21, C1.6 @ 12:26 UT
Region 13500 [S18E37] was mostly quiet despite its magnetic complexity. A major flare is still possible. C1 flares: C1.3 @ 20:07 UT
Region 13501 [S09E46] was quiet and stable.
Region 13502 [N14E04] decayed slowly and was mostly quiet. C1 flares: C1.9 @ 05:27 UT
New region 13503 [N20E59] rotated into view on November 23 and was numbered by SWPC 2 days later. C1 flares: C1.7 @ 12:44 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9156 [N22W13] decayed slowly and was mostly quiet. C1 flares: C1.5 @ 17:11 UT
S9173 [N12E19] was quiet and stable.
New region S9175 [N08W63] emerged with tiny spots.
New region S9176 [N12W53] emerged with tiny spots.
New region S9177 [N14W51] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.1 09:18   13499 GOES18  
C4.4 14:39   13503 GOES18 LDE

Coronal mass ejections (CMEs)

November 23-25: 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 positive polarity northern hemisphere coronal hole (CH1189) was Earth facing on November 23-24.

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 November 26-27 due to CME effects and effects from CH1189. Quiet to unsettled is likely on November 28.

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
13488 2023.11.14
2023.11.14
      N31W74          

location: N29W68

13489 2023.11.16
2023.11.17
3 16 7 S15W36 0030 HRX CRO

location: S14W35

S9151 2023.11.16       S24W58            
13497 2023.11.18
2023.11.20
      N17W20           location: N18W15
S9156 2023.11.18   16 6 N22W13 0150   CAO

SWPC apparently considers this region as two groups (13490 and 13495)

13490 2023.11.18 6     N21W16 0110 CAO        
S9157 2023.11.18       N13W57            
13492 2023.11.18
2023.11.20
11 31 15 N19W03 0240 CSI CSO

area: 0380

location: N18W04

13491 2023.11.18
2023.11.19
2 6 4 N10W09 0030 HRX BXO location: N10W08
13496 2023.11.19
2023.11.20
      N09W34           location: N07W31
13493 2023.11.20
2023.11.20
4 10 7 S13E05 0090 HSX CSO

area: 0150

location: S12E06

S9162 2023.11.20       S17W02            
13494 2023.11.20
2023.11.20
2 5 3 S18E09 0060 HSX CSO

area: 0160

13495 2023.11.20       N25W09           apparently the spots in  the northeastern part of AR S9156
S9166 2023.11.20       S33W04            
13498 2023.11.21
2023.11.21
1     S11W87 0030 HRX    

location: S11W85

rotated out of view

13500 2023.11.22
2023.11.23
13 34 17 S18E36 0560 DKC DKC beta-delta

location: S18E37

13499 2023.11.22
2023.11.23
8 19 17 S17W25 0060 CAI DAI area: 0120

location: S17W23

13501 2023.11.22
2023.11.23
1 3 1 S09E44 0060 HSX CSO area: 0140

location: S09E46

S9171 2023.11.22       N08W29            
13502 2023.11.22
2023.11.23
6 14 7 N14W01 0110 CAO DKO area: 0280

location: N14E04

S9173 2023.11.22   3 2 N12E19 0007   AXX  
13503 2023.11.23
2023.11.25
2 3 1 N21E58 0020 CRO HRX location: N20E59
S9175 2023.11.25   2   N08W63 0003   BXO    
S9176 2023.11.25   2 2 N12W53 0004   BXO    
S9177 2023.11.25   3 2 N14W51 0010   CRO    
Total spot count: 59 167 91  
Sunspot number: 179 317 231  (total spot count + 10 * number of spotted regions)
Weighted SN: 136 226 160  (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): 197 174 185  

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
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.4 (+4.4) 7.48
2022.06 116.1 119.8 70.3 81.1 (+3.7) 8.20
2022.07 125.4 129.5 91.4 86.7 (+5.6) 9.51
2022.08 114.2 117.1 74.6 92.6 (+5.9) 10.92
2022.09 135.1 136.5 96.0 96.5 (+3.9) 12.18
2022.10 133.5 132.7 95.5 98.9 (+2.4) 11.16
2022.11 123.4 120.7 80.5 101.2 (+2.3) 9.33
2022.12 147.9 143.4 112.8 106.7 (+5.5) 10.99
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
(current
SC25 peak)
2023.03 157.2 155.6 123.3 121.0 (+3.2) 14.42
2023.04 145.4 146.4 97.6 122.7 (+1.7) 13.40
2023.05 155.6 159.2 137.4 (124.7 projected, +2.0) 10.67
2023.06 161.7 166.8 160.5 (127.9 projected, +3.2) 8.95
2023.07  176.4 182.2 159.1 (128.3 projected, +0.4) 8.15
2023.08  153.7 157.6 114.8 (130.1 projected, +1.8) 7.19
2023.09  154.4 156.0 133.6 (133.5 projected, +3.4) 14.26
2023.10  142.8 141.9 99.4 (135.2 projected, +1.7) 8.16
2023.11 149.1 (1)   80.1 (2A) / 96.2 (2B) / 113.7 (2C) (137.8 projected max SC25, +2.6) (13.5)
2023.12       (137.1 projected, -0.7)  
2024.01       (134.4 projected, -2.7)  
2024.02       (134.2 projected, -0.2)  
2024.03       (133.7 projected, -0.5)  
2024.04       (134.5 projected, +0.8)  
2024.05       (135.8 projected, +1.3)  

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 August 20, 2023

Looking back 6 months, the 365d smoothed values for solar flux and all sunspot numbers with the exception of NOAA's, are all above their solar cycle 24 peak. The first peak of solar cycle 25 is forecast to be between July 7 and 10, 2023 (solar flux on July 7, ISN and STAR 1K and 2K all have that peak on July 9, while NOAA peaks on July 10). This is unlikely to be the final peak of SC25, however, there is a small probability that it is the actual sunspot and solar flux maximum.

--------------------------------------------------------------------------------------

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.