Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 9, 2023 at 08:00 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 active on November 8 under the influence of a high speed stream from CH1183. Solar wind speed at SOHO ranged between 651 and 771 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 145.7 - decreasing 11.4 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 16 (STAR Ap - based on the mean of three hour interval ap indices: 15.8). Three hour interval K indices: 23331243 (planetary), 24342333 (Boulder), 35322364 (Andenes).

The background x-ray flux is at the class B7 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 258) and in 9 active regions using 1K resolution (SN: 143) SDO/HMI images.

Region 13477 [S14W27] was mostly quiet and stable.
Region 13479 [N22W69] developed early in the day, then decayed slowly. C1 flares: C1.3 @ 00:42, C1.8 @ 02:57, C1.1 @ 17:10 UT
Region 13480 [S08W01] decayed slowly and was mostly quiet.
Region 13481 [N22W01] was quiet and stable.
Region 13482 [N03E29] was quiet and stable.
Region 13483 [N09W11] developed early in the day and had a central magnetic delta structure at noon. Then the region decayed slowly and lost the magnetic delta. C1 flares: C1.5 @ 02:30, C1.6 @ 03:53, C1.9 @ 05:08, C1.4 @ 06:17, C1.2 @ 14:47 UT
New region 13484 [S16W08] emerged slowly with tiny spots.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9125 [N28W32] was quiet and stable.
S9128 [N25W09] was quiet and stable.
S9129 [S18E33] was quiet and stable.
New region S9130 [S22W03] emerged before noon, then decayed slowly.
New region S9132 [N13W38] emerged with a tiny spot.
New region S9133 [N05E64] emerged with a tiny spot.
New region S9134 [N25E01] emerged with a tiny spot.

A C1.8 flare was recorded at 07:23 UT from a location on the northwest limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.3 01:00   13483 GOES16  
C4.7 03:09 N09E03 13483 GOES16  
C6.8 08:48 N08W00 13483 GOES16  
C4.2 20:13 N09W08 13483 GOES16  
C3.4 20:29   13483 GOES16  

Coronal mass ejections (CMEs)

November 6-8: 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 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 9 due to effects from CH1183. Quiet is likely on November 10-11.

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 16 6 N22W72 0080 CAO DRI

location: N22W69

13478 2023.10.31
2023.11.01
      N12W25          

location: N13W21

13477 2023.10.31 6 22 10 S15W25 0240 CAO CKO

area: 0360

location: S14W27

S9111 2023.11.01       N25W54            
S9113 2023.11.01       S37W59            
13480 2023.11.02
2023.11.03
6 28 10 S08W00 0050 CAO CRO

area: 0060

location: S08W01

13481 2023.11.02
2023.11.04
  2 1 N25W08 0006   AXX location: N22W01
13482 2023.11.04
2023.11.05
1 4 2 N03E28 0010 HRX HRX

location: N03E29

area: 0030

13483 2023.11.05
2023.11.07
13 27 16 N09W09 0100 DSI DAI beta-gamma

location: N09W11

area: 0290

S9123 2023.11.05       S31W08            
S9125 2023.11.06   1 1 N28W32 0003   AXX  
S9126 2023.11.06       S34E08            
S9127 2023.11.06       S29E23            
S9128 2023.11.07   7 4 N25W09 0020   BXO  
S9129 2023.11.07   1   S18E33 0002   AXX  
S9130 2023.11.08   2   S22W03 0003   AXX    
13484 2023.11.08
2023.11.08
2 4 3 S16W08 0010 AXX BXO   was AR S9131
S9132 2023.11.08   1   N13W38 0001   AXX    
S9133 2023.11.08   1   N05E64 0002   AXX    
S9134 2023.11.08   2   N25E31 0004   AXX    
Total spot count: 32 118 53  
Sunspot number: 92 258 143  (total spot count + 10 * number of spotted regions)
Weighted SN: 52 142 77  (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): 101 142 114  

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
2023.11 152.5 (1)   24.0 (2A) / 90.1 (2B) / 107.5 (2C) (137.8 projected max SC25, +2.6) (20.2)
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.