Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 4, 2023 at 11:25 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 (October 8, 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 very quiet on November 3. Solar wind speed at SOHO ranged between 322 and 408 km/sec. The high latitude magnetometer at Andenes recorded quiet levels.

Solar flux density measured at 20h UT on 2.8 GHz was 156.1 - decreasing 1.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.05. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.5). Three hour interval K indices: 11111000 (planetary), 01211200 (Boulder), 21100000 (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 14 active regions using 2K resolution (SN: 267) and in 12 active regions using 1K resolution (SN: 180) SDO/HMI images.

Region 13472 [N20W64] was quiet and stable.
Region 13473 [N17W36] decayed slowly and was mostly quiet. C1 flares: C1.4 @ 04:26 UT
Region 13474 [S18W57] decayed slowly and was mostly quiet.
Region 13476 [S13W27] decayed slowly and quietly.
Region 13477 [S14E39] was mostly quiet and stable. C1 flares: C1.5 @ 09:04 UT
Region 13478 [N12E43] was quiet and stable.
Region 13479 [N22W02] was quiet and stable.
New region 13480 [S08E67] rotated into view on November 2 and was numbered by SWPC the next day. The region decayed significantly in the trailing spot section and was much less active than during the previous days.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9107 [S20W09] decayed slowly and quietly.
S9111 [N25E11] reemerged with tiny spots.
S9115 [N20E61] was quiet and stable.
New region S9117 [S10E04] emerged with tiny spots.
New region S9118 [S06W33] emerged with tiny spots.
New region S9119 [N35E17] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.5 01:32   13480 GOES16  
C3.3 06:16   filament eruption GOES16 LDE
C2.5 07:31   13474 GOES16  
C2.2 07:48   13480 GOES16  
C3.4 22:38   13480 GOES16  

Coronal mass ejections (CMEs)

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 could reach Earth on October 6.
November 2: Several CMEs were observed during the day. The most interesting one was associated with an eruption in the northeastern quadrant starting near 02:30 UT in SDO/AIA imagery. At least a partial halo CME was observed after this event and there's a fair chance CME components could reach Earth on November 5.
November 1: No obviously Earth directed CMEs were observed.
October 31: A CME was observed starting at 22:12 UT in LASCO C2 imagery after a filament eruption in the central southern hemisphere. The core of the CME was observed off the south pole, weak extensions were seen off the southwest limb. Analysis was somewhat complicated due to a CME off the east limb (from a source just behind the southeast limb) that started at 21:12 UT in LASCO imagery, and it is uncertain if components of the CME related to the filament eruption will reach Earth. Three is a minor chance of weak CME effects on November 3-4.

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 poor to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on November 4. Unsettled and active intervals are possible on November 4 should components of the October 31 CME reach Earth. Quiet to minor storm conditions are possible on November 5 should the November 2 CME become geoeffective. Unsettled to minor storm is possible on November 6 due to the Nov.3 CME. 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
S9087 2023.10.25       N19W50            
13472 2023.10.25
2023.10.26
5 12 6 N21W67 0030 CAO DRO area: 0040

location: N20W64

S9089 2023.10.25       N11W44          
13473 2023.10.25
2023.10.26
1 11 4 N17W31 0010 AXX BXO area: 0020

location: N17W36

13474 2023.10.26
2023.10.27
16 24 13 S18W57 0330 DHO EKO beta-gamma
S9097 2023.10.27       S14W47            
13476 2023.10.28
2023.10.31
  2 1 S15W33 0005   AXX location: S13W27
S9103 2023.10.28       S23W54            
S9106 2023.10.30       N12W16          
S9107 2023.10.30   7 2 S20W09 0012   BXO  
S9108 2023.10.30       S15W43            
13479 2023.10.31
2023.11.02
1 15 4 N21W05 0020 AXX BXO area: 0030

location: N22W02

13478 2023.10.31
2023.11.01
1 7 3 N12E43 0010 AXX CRO area: 0020
13477 2023.10.31 5 18 11 S15E42 0310 CKO EKO area: 0460

location: S14E39

S9111 2023.11.01   4 1 N25E11 0007   BXO    
S9112 2023.11.01       N17W26            
S9113 2023.11.01       S37E06            
13480 2023.11.02
2023.11.03
7 14 10 S11E64 0150 DAC DAC area: 0350
S9115 2023.11.02   7 3 N20E61 0030   CRO  
S9116 2023.11.02       N00W05          
S9117 2023.11.03   3 2 S10E04 0008   BXO    
S9118 2023.11.03   2   S06W33 0003   BXO    
S9119 2023.11.03   1   N35E17 0001   AXX    
Total spot count: 36 127 60  
Sunspot number: 106 267 180  (total spot count + 10 * number of spotted regions)
Weighted SN: 61 161 96  (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): 117 147 144  

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) 8.2
2023.11 157.7 (1)   10.8 (2A) / 108.0 (2B) / 115.5 (2C) (137.8 projected max SC25, +2.6) (5.4)
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.