Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 13, 2023 at 07:35 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 12 under the influence of CME effects. Solar wind speed at SOHO ranged between 452 and 608 km/sec. The high latitude magnetometer at Andenes recorded quiet levels. The Bz component of the IMF took a deep southwards dive starting at 22:07 UT at DSCOVR. This caused a severe storm interval early on November 13 at high latitude magnetometers.

Solar flux density measured at 20h UT on 2.8 GHz was 137.2 - decreasing 6.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 156.35. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.3). Three hour interval K indices: 11432113 (planetary), 01532213 (Boulder), 11222112 (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 9 active regions using 2K resolution (SN: 161) and in 8 active regions using 1K resolution (SN: 117) SDO/HMI images.

Region 13477 [S15W81] decayed slowly and was mostly quiet. C1 flares: C1.6 @ 13:34 UT
Region 13480 [S11W47] decayed slowly and quietly.
Region 13482 [N05W23] reemerged with tiny spots.
Region 13483 [N07W67] gained area and lost some spots. A major flare is still possible. C1 flares: C1.1 @ 00:25, C1.7 @ 17:45 UT
Region 13484 [S14W67] matured gaining area and losing spots. C1 flares: C1.8 @ 07:20, C1.3 @ 07:53, C1.3 @ 08:17, C1.3 @ 09:05, C1.5 @ 10:40, C1.9 @ 12:48, C1.6 @ 15:58, C1.3 @ 20:47, C1.1 @ 22:43, C1.1 @ 23:56 UT
Region 13485 [S18W53] matured and was mostly quiet.
New region 13486 [S10W07] emerged on November 11 and was numbered the next day by SWPC. C1 flares: C1.6 @ 11:31, C1.6 @ 15:01, C1.5 @ 17:31, C1.3 @ 19:18 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9134 [N25W33] was quiet and stable
New region S9137 [N17E05] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C8.4 04:41   13484 GOES16  
C2.0 06:17   13485 GOES16  
C2.4 09:50   13484 GOES16  

Coronal mass ejections (CMEs)

November 10-12: 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 small positive polarity southern hemisphere coronal hole (CH1184) was Earth facing on November 10. A small negative polarity trans equatorial coronal hole (CH1185) was Earth facing on November 12.

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 to minor storm on November 13 due to CME effects. On November 14 quiet to active conditions are likely due to effects from CH1184. November 15 could see quiet to unsettled conditions.

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
      N12W81          

location: N13W73

13477 2023.10.31 2 3 1 S15W81 0160 CAO HSX

area: 0260

13480 2023.11.02
2023.11.03
  2 1 S19W56 0008   AXX

location: S11W47

SWPC location is way off

13481 2023.11.02
2023.11.04
      N25W64          

actual location: N21W54

SWPC has moved this region to the location of AR S9128

13482 2023.11.04
2023.11.05
  4   N04W29 0008   BXO  

location: N05W23

13483 2023.11.05
2023.11.07
8 14 5 N09W65 0290 DKI DKO

location: N07W67

area: 0740

S9126 2023.11.06       S34W44            
S9127 2023.11.06       S29W29            
S9129 2023.11.07       S18W19            
13485 2023.11.08
2023.11.10
6 13 9 S19W52 0080 DAI DAO area: 0160

location: S18W53

13484 2023.11.08
2023.11.08
8 12 8 S15W62 0080 CAI DAO location: S14W67

area: 0150

S9133 2023.11.08       N08E12          
S9134 2023.11.08   3 1 N25W23 0007   AXX  
S9135 2023.11.10       S10W19            
13486 2023.11.11
2023.11.12
4 16 11 S09W08 0100 DAO DAO area: 0200

location: S10W07

S9137 2023.11.12   4 1 N17E05 0009   BXO    
Total spot count: 28 71 37  
Sunspot number: 78 161 117  (total spot count + 10 * number of spotted regions)
Weighted SN: 58 101 67  (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): 86 89 94  

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
2023.11 148.5 (1)   35.7 (2A) / 89.1 (2B) / 102.8 (2C) (137.8 projected max SC25, +2.6) (16.1)
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.