Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 10, 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 (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 9 under the slowly weakening influence of a high speed stream from CH1183. Solar wind speed at DSCOVR/ACE ranged between approx. 450 and 680 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 138.7 - decreasing 10.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.32. 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: 10.6). Three hour interval K indices: 33322233 (planetary), 21322332 (Boulder), 43422364 (Andenes).

The background x-ray flux is at the class B6 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 215) and in 8 active regions using 1K resolution (SN: 138) SDO/HMI images.

Region 13477 [S14W40] gained a few spots and was mostly quiet. C1 flares: C1.8 @ 16:15 UT
Region 13479 [N23W80] decayed slowly and quietly.
Region 13480 [S08W14] decayed slowly and was mostly quiet.
Region 13481 [N21W15] decayed slowly and was mostly quiet. C1 flares: C1.2 @ 10:50 UT
Region 13482 [N04E16] decayed slowly and quietly.
Region 13483 [N09W25] has a weak magnetic delta in the trailing spot section and a minor M class flare is possible. C1 flares: C1.0 @ 01:19, C1.1 @ 07:20, C1.1 @ 08:30, C1.3 @ 10:55, C1.7 @ 16:02, C1.0 @ 17:59 UT (triggered by filament eruption)
Region 13484 [S13W22] gained spots and was mostly quiet.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9128 [N25W23] developed slowly and quietly. SWPC failed to observe that this is a separate region from AR 13481 and moved the location of that region northwestwards to include the spots of AR S9128.
S9130 [S19W11] was quiet and stable.
S9133 [N05E51] was quiet and stable.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 11:18   13481 GOES16 impulsive flare superimposed on LDE associated with filament eruption
Flare started at 11:16 and ended at 11:21 UT, probably triggered by the filament eruption
C2.0 14:27   13483 GOES16  

Coronal mass ejections (CMEs)

November 7-8: 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 on November 12.

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) was 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 poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be at quiet to unsettled levels on November 10 due to effects from CH1183. Quiet is likely on November 11. Quiet to minor storm conditions are likely on November 12-13 due to CME 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
13479 2023.10.31
2023.11.02
4 3 2 N22W80 0060 CAO CRO

location: N22W80

area: 0030

13478 2023.10.31
2023.11.01
      N12W39          

location: N13W34

13477 2023.10.31 7 26 15 S15W39 0230 CAO DKO

area: 0330

location: S14W40

13480 2023.11.02
2023.11.03
2 17 7 S08W14 0030 CRO CRO

area: 0040

13481 2023.11.02
2023.11.04
3 2   N25W19 0030 BXO BXO location: N21W15

SWPC includes the spots of AR S9128

13482 2023.11.04
2023.11.05
1 4 2 N04E16 0010 AXX HRX

area: 0015

13483 2023.11.05
2023.11.07
16 33 19 N09W23 0120 EAI DAI beta-delta

location: N09W25

area: 0260

S9123 2023.11.05       S31W21            
S9125 2023.11.06       N28W45          
S9126 2023.11.06       S34W05            
S9127 2023.11.06       S29E10            
S9128 2023.11.07   9 4 N25W23 0020   CRO  
S9129 2023.11.07       S18E20          
S9130 2023.11.08   3   S19W11 0006   BXO  
13484 2023.11.08
2023.11.08
  17 8 S19W19 0030   CRI location: S13W22
S9132 2023.11.08       N13W51          
S9133 2023.11.08   1 1 N05E51 0002   AXX  
S9134 2023.11.08       N25E18          
Total spot count: 33 115 58  
Sunspot number: 93 215 138  (total spot count + 10 * number of spotted regions)
Weighted SN: 51 145 88  (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): 102 118 110  

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
2023.11 151.0 (1)   27.1 (2A) / 90.4 (2B) / 105.9 (2C) (137.8 projected max SC25, +2.6) (19.1)
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.