Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 28, 2023 at 04:25 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 (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 (November 26, 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 on November 27, weakly under decreasing effects from CH1189. Solar wind speed at SOHO ranged between 412 and 500 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 18h UT on 2.8 GHz was 179.8 - increasing 32.5 over the previous solar rotation (the measurement at 20h UT was flare enhanced). (Centered 1 year average SF at 1 AU - 183 days ago: 157.72. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.4). Three hour interval K indices: 21222212 (planetary), 12212221 (Boulder), 33111325 (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: 293) and in 13 active regions using 1K resolution (SN: 212) SDO/HMI images.

Region 13489 [S14W62] decayed slowly and was mostly quiet.
Region 13492 [N18W30] decayed slowly and was mostly quiet. C1 flares: C1.7 @ 04:25, C1.6 @ 05:23 UT
Region 13493 [S12W20] was quiet and stable.
Region 13494 [S17W14] was quiet and stable.
Region 13499 [S17W47] decayed slowly and was mostly quiet. C1 flares: C1.5 @ 16:34 UT
Region 13500 [S18E11] decayed slowly and was mostly quiet. C1 flares: C1.5 @ 11:57, C1.4 @ 22:06 UT
Region 13501 [S09E19] was quiet and stable.
Region 13502 [N14W23] decayed slowly and was mostly quiet.
Region 13503 [N21E34] decayed slowly and quietly.
Region 13504 [N11W81] was mostly quiet and stable. C1 flares: C1.7 @ 04:41 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9156 [N22W40] decayed slowly and quietly.
S9173 [N14W07] was quiet and stable.
S9178 [N11E08] was quiet and stable.
New region S9182 [S16E81] rotated into view.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.4 05:51   13489 GOES18  
C2.7 06:01 southeast limb S9182 GOES18  
C3.3 06:12   13502 GOES18 LDE
C3.4 08:11 N20W31 S9156 GOES18  
C2.6 13:17   13489 GOES18  
C3.8 18:37   S9178 GOES18 associated filament eruption
C6.7 18:52   13500 GOES18 LDE
C5.5 23:40   13503 GOES18 LDE+associated filament eruption

Coronal mass ejections (CMEs)

November 25-26: No obviously Earth directed CMEs were observed.
November 27: Several CMEs were observed during the day. The first one involved a filament eruption beginning just before 05h UT in SDO/AIA imagery. The eruption in the southwestern quadrant extended from close to the central meridian at its southernmost point to near the equator in the northwestern part of the filament channel. Coronal dimming was observed. A partial halo CME was observed and could reach Earth early on November 30. The second filament eruption began near 18:17 UT and occurred in the northeastern quadrant. The eruption affected areas as far south as AR 13500 and resulted in at least a partial halo CME, maybe a faint full halo CME. This CME is likely to reach Earth on November 30. The third filament eruption also occurred in the northeastern quadrant and further east than the previous eruption. This event began near 23:07 in SDO/AIA imagery. A partial halo CME was observed after this event and could influence Earth on December 1.

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 recurrent negative polarity southern hemisphere coronal hole (CH1190) will likely rotate across the central meridian on December 1-2.

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 quiet on November 28-29. Late on November 29 or early on November 30 the first of the November 27 CMEs could reach Earth and cause unsettled to minor storm conditions. The second CME will likely arrive a little later and could increase the disturbance to major storm levels. The last of the Nov.27 CMEs may have an Earth directed component that could reach us on December 1.

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
13489 2023.11.16
2023.11.17
2 3 1 S15W64 0005 AXX BXO

location: S14W62

13497 2023.11.18
2023.11.20
      N17W49           location: N18W41
S9156 2023.11.18   7 4 N22W40 0030   CRO

SWPC apparently considers this region as two groups (13490 and 13495)

13490 2023.11.18 4     N22W42 0040 CAO        
13492 2023.11.18
2023.11.20
4 20 8 N19W33 0190 DSO CSO

area: 0280

location: N18W30

13491 2023.11.18
2023.11.19
      N11W38           location: N10W34
13496 2023.11.19
2023.11.20
      N09W63           location: N07W57
13493 2023.11.20
2023.11.20
3 17 8 S13W22 0030 HSX CSO

area: 0080

location: S12W20

S9162 2023.11.20       S17W28            
13494 2023.11.20
2023.11.20
1 5 2 S18W18 0060 HSX CSO

area: 0140

location: S17W14

13495 2023.11.20       N25W38           apparently the spots in  the northeastern part of AR S9156
S9166 2023.11.20       S33W30            
13500 2023.11.22
2023.11.23
12 35 21 S20E08 0320 DKC DAC beta-gamma

location: S18E11

area: 0550

13499 2023.11.22
2023.11.23
12 20 13 S17W52 0030 DRI DRI

area: 0070

location: S17W47

13501 2023.11.22
2023.11.23
1 5 2 S10E17 0090 HSX CSO area: 0140

location: S09E19

S9171 2023.11.22       N08W55            
13502 2023.11.22
2023.11.23
7 17 12 N14W28 0080 CAO CAO area: 0120

location: N14W23

S9173 2023.11.22   4 2 N14W07 0007   AXX  
13503 2023.11.23
2023.11.25
1 10 4 N15E31 0010 HRX CRO location: N21E34

area: 0030

SWPC location is way off

13504 2023.11.25
2023.11.26
2 5 4 N14W79 0030 DRO CRO

location: N12W81

S9178 2023.11.26   4   N11E08 0008   BXO  
S9180 2023.11.26       N38W16          
S9181 2023.11.26       S19W36          
S9182 2023.11.27   1 1 S16E81 0080   HAX    
Total spot count: 49 153 82  
Sunspot number: 159 293 212  (total spot count + 10 * number of spotted regions)
Weighted SN: 98 200 129  (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): 175 161 170  

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
2023.11 151.4 (1)   91.1 (2A) / 101.2 (2B) / 119.5 (2C) (137.8 projected max SC25, +2.6) (13.1)
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.