Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 6, 2023 at 06:30 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 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 (July 10, 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 severe storm on November 5. Solar wind speed at SOHO ranged between 331 and 577 km/sec. The high latitude magnetometer at Andenes recorded quiet to severe storm levels. At 08:13 UT on November 5 a strong solar wind shock was observed at SOHO, the arrival of the November 2. Another and even stronger solar wind shock was recorded at 11:55 UT at SOHO. This was the arrival of the November 3 CME.

Solar flux density measured at 20h UT on 2.8 GHz was 154.8 - decreasing 10.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.21. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 62 (STAR Ap - based on the mean of three hour interval ap indices: 61.6). Three hour interval K indices: 32266775 (planetary), 32555654 (Boulder), 31155755 (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 9 active regions using 2K resolution (SN: 200) and in 9 active regions using 1K resolution (SN: 136) SDO/HMI images.

Region 13474 [S18W85] rotated partly out of view and was quiet.
Region 13477 [S14E13] was mostly quiet and stable.
Region 13478 [N12E17] decayed slowly and was mostly quiet. C1 flares: C1.3 @ 09:00 UT
Region 13479 [N21W29] decayed slowly and quietly.
Region 13480 [S09E39] decayed significantly and produced several flare including 2 minor M class flares. C1 flares: C1.4 @ 09:54, C1.6 @ 10:53. C1.5 @ 11:21, C1.4 @ 16:35 UT
Region 13481 [N21E37] decayed slowly and quietly.
New region 13482 [N03E68] rotated into view on November 4 and was numbered the next day by SWPC.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
New region S9122 [N10E32] emerged with tiny spots.
New region S9123 [S31E31] emerged with tiny spots.

AR 13472 at the northwest limb produced a C1.0 flare at 02:20, a C1.9 flare at 21:16 and a C1.5 flare at 00:02 UT (start time 23:48 UT).

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
M1.8/1N 11:43 S09E53 13480 GOES16  
C2.1 13:28   13480 GOES16 incorrectly attributed to AR 13472 by SWPC
M1.6 14:32   13480 GOES16  
C4.4 17:41   13480 GOES16  
C2.5 20:10   13480 GOES16  
C9.3 21:34 S08E47 13480 GOES16  

Coronal mass ejections (CMEs)

November 4-5: No obviously Earth directed CMEs were observed.
November 3: A CME was observed following a large (almost 50 degrees long) filament eruption in the northwestern quadrant (from the central meridian and westwards) early in the day. The CME reached Earth on November 5.

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 large and well defined negative polarity trans equatorial coronal hole (CH1183) will be Earth facing on November 4-6.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is very poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be at quiet to major storm levels on November 6 due to CME effects. Quiet to major storm is possible on November 7-8 due to effects from CH1183.

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
13473 2023.10.25
2023.10.26
      N17W59        

location: N18W61

13474 2023.10.26
2023.10.27
2 2 1 S18W82 0200 CSO CSO location: S18W85
13476 2023.10.28
2023.10.31
      S15W61           location: S13W53
S9106 2023.10.30       N12W33            
S9107 2023.10.30       S20W35            
13479 2023.10.31
2023.11.02
3 19 5 N22W28 0010 BXO CRO area: 0035

location: N21W29

13478 2023.10.31
2023.11.01
1 9 2 N12E17 0010 AXX AXX area: 0015
13477 2023.10.31 8 26 16 S15E18 0350 CKO DKO beta-gamma

area: 0520

location: S14E13

S9111 2023.11.01       N25W15            
S9112 2023.11.01       N17W52            
S9113 2023.11.01       S37W20            
13480 2023.11.02
2023.11.03
6 41 17 S09E40 0180 DAI DAI

area: 0220

13481 2023.11.02
2023.11.04
  7 2 N20E34 0015   BXO location: N21E37
S9116 2023.11.02       N00W31            
S9117 2023.11.03       S10W22            
S9118 2023.11.03       S06W59            
S9119 2023.11.03       N35W09            
S9120 2023.11.04       S11W41          
13482 2023.11.04
2023.11.05
1 1 1 N02E68 0030 HRX HRX  
S9122 2023.11.05   2 1 N10E32 0006   BXO    
S9123 2023.11.05   3 1 S31E31 0005   AXX    
Total spot count: 21 110 46  
Sunspot number: 81 200 136  (total spot count + 10 * number of spotted regions)
Weighted SN: 44 136 72  (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): 89 110 109  

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
2023.11 156.6 (1)   16.7 (2A) / 100.0 (2B) / 112.1 (2C) (137.8 projected max SC25, +2.6) (18.1)
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.

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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.