Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 11, 2023 at 08:45 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 10 under the slowly weakening influence of a high speed stream from CH1183. Solar wind speed at SOHO ranged between 547 and 759 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 143.9 - decreasing 4.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.34. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.1). Three hour interval K indices: 23222112 (planetary), 23332211 (Boulder), 34332124 (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 8 active regions using 2K resolution (SN: 189) and in 8 active regions using 1K resolution (SN: 143) SDO/HMI images.

Region 13477 [S14W55] decayed slowly and produced several C flares. C1 flares: C1.1 @ 10:40, C1.4 @ 11:53, C1.6 @ 14:01, C1.3 @ 16:30, C1.6 @ 18:36 UT
Region 13480 [S09W23] decayed slowly and quietly.
Region 13483 [N08W40] developed slowly and has at least one weak magnetic delta structure. An M class flare is possible. Several C flares have been observed early on November 11. C1 flares: C1.0 @ 06:35. C1.7 @ 23:10 UT
Region 13484 [S14W35] developed slowly and quietly.
New region 13485 [S18W25] was first observed with spots on November 8. New flux emerged on November 10 and several spots formed. C1 flares: C1.0 @ 17:26 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9128 [N25W37] decayed slowly and quietly.
S9133 [N06E40] was quiet and stable.
New region S9135 [S10E07] emerged with a tiny spot.

AR 13479 behind the northwest limb produced a C1.0 flare at 02:11 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.2 12:14 S17W41 13477 GOES16  
C3.4 16:04   13477 GOES16  
C2.4 20:20   13477 GOES16  
C2.7 20:47   13477 GOES16  
C2.8 21:00   13477 GOES16  
C2.1 21:31   13477 GOES16  

Coronal mass ejections (CMEs)

November 8, 10: No obviously Earth directed CMEs were observed.
November 9: A full halo CME was observed after a complex event before noon involving a filament eruption and ARs 13484, 13483 and 13480. The filament eruption was the likely trigger of small flares in ARs 13480 and 13483. The CME will likely reach Earth between late on November 11 and noon on November 12. Proton levels increased after 16h UT, probably associated with this event.

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.

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 very poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on November 11. The November 9 CME could arrive late in the day or on November and cause unsettled to major storm conditions until November 13. On November 14 quiet to active conditions are likely due to effects from CH1184.

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
13478 2023.10.31
2023.11.01
      N12W53          

location: N13W47

13477 2023.10.31 8 15 9 S15W53 0240 DAO CKO

area: 0310

13480 2023.11.02
2023.11.03
3 23 6 S09W26 0020 BXO BXI

area: 0030

location: S09W23

13481 2023.11.02
2023.11.04
1     N25W37 0010 AXX     spotless

actual location: N21W28

SWPC has moved this region to the location of AR S9128

13482 2023.11.04
2023.11.05
      N04E01        

 

13483 2023.11.05
2023.11.07
12 35 22 N10W38 0180 DAI DAI beta-gamma-delta

location: N08W40

area: 0350

S9123 2023.11.05       S31W34            
S9125 2023.11.06       N28W58            
S9126 2023.11.06       S34W18            
S9127 2023.11.06       S29W03            
S9128 2023.11.07   2 2 N25W37 0010   AXX  
S9129 2023.11.07       S18E07            
13485 2023.11.08
2023.11.10
3 10 8 S19W25 0020 BXO CRO area: 0040
13484 2023.11.08
2023.11.08
6 20 14 S14W34 0030 BXO CRI location: S14W35

area: 0070

S9133 2023.11.08   3 1 N06E40 0007   AXX  
S9134 2023.11.08       N25E05            
S9135 2023.11.10   1 1 S10E07 0002   AXX    
Total spot count: 33 109 63  
Sunspot number: 93 189 143  (total spot count + 10 * number of spotted regions)
Weighted SN: 43 130 84  (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): 102 104 114  

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
2023.11 150.3 (1)   30.2 (2A) / 90.7 (2B) / 104.8 (2C) (137.8 projected max SC25, +2.6) (18.0)
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.