Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 16, 2023 at 04:50 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 unsettled on November 15 under the influence of effects from CH1184. Solar wind speed at SOHO ranged between 364 and 442 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 118.9 - decreasing 9.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.24. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.4). Three hour interval K indices: 32223332 (planetary), 21334322 (Boulder), 42122364 (Andenes).

The background x-ray flux is at the class B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 96) and in 5 active regions using 1K resolution (SN: 67) SDO/HMI images.

Region 13486 [S09W47] decayed slowly and was mostly quiet.
Region 13487 [S17W60] decayed slowly and quietly.
Region 13488 [N29E64] decayed slowly and quietly

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
New region S9146 [N16W22] emerged with tiny spots.
New region S9147 [N16E22] emerged with tiny spots.
New region S9148 [S15W07] was observed with tiny spots in an old plage area.

AR 13483 behind the northwest limb
AR 13484 behind the southwest limb produced several C1 flares: C1.5 @ 03:20, C1.8 @ 03:51, C1.4 @ 06:16, C1.1 @ 08:23, C1.5 @ 09:15, C1.7 @ 09:25, C1.5 @ 10:59, C1.5 @ 11:29, C1.7 @ 13:03, C1.4 @ 17:16, C1.2 @ 19:02 UT
AR 13485 at the southwest limb produced these C1 flares: C1.5 @ 10:00, C1.3 @ 15:53 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C8.3 04:01   13485 GOES18  
C2.8 04:32     GOES18  
C7.6 12:12 southwest limb 13485 GOES18  

Coronal mass ejections (CMEs)

November 13-15: 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 small positive polarity southern hemisphere coronal hole (CH1184) was Earth facing on November 10. A small negative polarity trans equatorial coronal hole (CH1185) was Earth facing on November 12. A small negative polarity northern hemisphere hole (CH1186) rotated over the central meridian on November 14.

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 active due to effects from CH1185 on November 16 and quiet to unsettled on November 17-18 related to CH1186 effects.

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
13482 2023.11.04
2023.11.05
      N04W71          

location: N05W62

S9129 2023.11.07       S18W58            
S9133 2023.11.08       N08W27            
S9135 2023.11.10       S10W58            
13486 2023.11.11
2023.11.12
8 14 9 S08W49 0190 DAO DAO area: 0280

location: S09W47

S9137 2023.11.12       N14W30          
13487 2023.11.13
2023.11.13
2 8 4 S17W61 0010 BXO DRO location: S17W60

area: 0025

S9139 2023.11.13       N07W21            
S9140 2023.11.13       N14W22            
S9141 2023.11.13       N25E54            
S9142 2023.11.13       N09E22            
13488 2023.11.14
2023.11.14
1 5 1 N29E63 0010 AXX BXO

 

S9144 2023.11.14       N44W46          
S9145 2023.11.14       S11W07          
S9146 2023.11.15   3 2 N16W22 0012   BXO    
S9147 2023.11.15   4   N16E22 0007   BXO    
S9148 2023.11.15   2 1 S15W07 0005   AXX    
Total spot count: 11 36 17  
Sunspot number: 41 96 67  (total spot count + 10 * number of spotted regions)
Weighted SN: 16 44 25  (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): 45 53 54  

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
2023.11 145.6 (1)   41.4 (2A) / 88.6 (2B) / 99.4 (2C) (137.8 projected max SC25, +2.6) (15.2)
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.