Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 25, 2022 at 10:25 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 (September 1, 2022)
Solar cycle Solar cycles 23-25 (September 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (September 1, 2022) 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 (September 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (September 1, 2022) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (August 21, 2022) 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 September 24 under the influence of effects associated with CH1101. Solar wind speed at SOHO ranged between 381 and 455 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 146.5 - increasing 13.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 113.17). The Potsdam WDC planetary A index was 12 (STAR Ap - based on the mean of three hour interval ap indices: 12.0). Three hour interval K indices: 24233332 (planetary), 34332432 (Boulder), 30134334 (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 9 active regions using 2K resolution (SN: 305) and in 7 active regions using 1K resolution (SN: 186) SDO/HMI images.

Region 13102 [S27W80] decayed slowly and was mostly quiet. C1 flares: C1.9 @ 15:42 UT
Region 13105 [S17E09] decayed slowly and quietly losing some penumbral area.
Region 13106 [S12W03] was quiet and stable.
Region 13107 [S23E25] has many spots and significant polarity intermixing. M class flares are possible.
Region 13108 [S12W24] decayed slowly and quietly.
Region 13109 [N09W39] decayed slowly and was mostly quiet. C1 flares: C1.9 @ 07:29 UT
Region 13110 [N17E58] developed slowly and has 2 small magnetic delta structures. M flares are possible. C1 flares: C1.9 @ 05:42, C1.8 @ 05:53, C1.6 @ 09:48, C1.9 @ 11:43 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S7887 [N19E09] developed slowly and quietly.
New region S7888 [N03W21] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.7 00:17   13110 GOES16  
C2.4 00:50   13110 GOES16  
C3.2 02:42   13107 GOES16  
C3.1 03:35   13107 GOES16  
C3.0 03:57   13110 GOES16  
C2.2 04:13   13110 GOES16  
C2.0 04:42   13110 GOES16  
C4.2 04:46   13110 GOES16  
C2.2 06:49 N15E69 13110 GOES16  
C3.0 07:02 S25E35 13107 GOES16  
C2.1 07:52 N15E77 13110 GOES16  
C2.1 08:27   13110 GOES16  
C2.4 10:51   13102 GOES16  
C4.3 12:36   13107 GOES16  
C5.0 13:21   13107 GOES16  
C3.0 14:37 N19E69 13110 GOES16  
C3.8 14:53   13110 GOES16  
C7.2 16:07 S23E32 13107 GOES16  
C2.9 16:50 S22E29 13107 GOES16  
C7.2 17:19   13110 GOES16 LDE
C3.4 18:18   13107 GOES16 LDE
C6.1 18:47 N18E68 13110 GOES16  
C2.8 21:55   13110 GOES16  
C2.5 23:06 S24E23 13107 GOES16  

Coronal mass ejections (CMEs)

September 22-24: 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 recurrent southern hemisphere coronal hole (CH1102) rotated across the central meridian on September 22-24. A recurrent trans equatorial coronal hole (CH1103) is expected to be Earth facing September 27-29.

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

Quiet to active conditions are possible on September 25-27 due to effects from CH1102.

Coronal holes (1) Coronal mass ejection (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
13102 2022.09.12
2022.09.13
3 2 2 S26W79 0100 DAO DSO

location: S27W80

area: 0180

13105 2022.09.19
2022.09.19
24 59 35 S17E08 0300 DKI EAI

location: S16E22

13106 2022.09.19
2022.09.20
  2   S12W04 0003   BXO

location: S12W03

13108 2022.09.20
2022.09.21
7 24 16 S12W24 0070 DSO DSI  
13107 2022.09.20
2022.09.21
17 75 38 S25E26 0240 FAI FAI beta-gamma

location: S23E25

area: 0350

13109 2022.09.21
2022.09.22
6 19 9 N10W40 0030 DRO DRO  
13110 2022.09.22
2022.09.23
11 25 13 N16E59 0240 DSC ESC beta-gamma-delta

location: N17E58

area: 0400

S7885 2022.09.23       N12W23          
S7886 2022.09.23       N30E02          
S7887 2022.09.23   8 3 N19E09 0020   DRO  
S7888 2022.09.24   1   N03W21     AXX    
Total spot count: 68 215 116  
Sunspot number: 128 305 186  (total spot count + 10 * number of spotted regions)
Weighted SN: 101 246 147  (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): 141 168 149  

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 (solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(cycle 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
2021.02 74.3 72.4 8.2 19.0 (+1.7) 9.50
2021.03 76.0 75.2 17.2 21.7 (+2.7) 10.17
2021.04 75.9 76.4 24.5 24.8 (+3.1) 8.40
2021.05 75.3 77.1 21.2 25.8 (+1.0) 6.50
2021.06 79.4 81.8 25.0 27.6 (+1.8) 5.52
2021.07 81.0 83.6 34.3 31.4 (+3.8) 5.51
2021.08 77.7 79.7 22.0 35.4 (+4.0) 6.19
2021.09 87.0 88.2 51.3 40.2 (+4.8) 6.33
2021.10 88.9 88.3 37.4 45.2 (+5.0) 7.38
2021.11 86.2 84.4 34.8 50.8 (+5.6) 9.83
2021.12 103.0 99.8 67.5 55.9 (+5.1) 6.40
2022.01 103.8 100.5 55.3 60.1 (+4.2) 8.92
2022.02 109.1 106.5 60.9 64.8 (+4.7) 10.46
2022.03 117.0 115.8 78.6 (68.7 projected, +3.9) 10.20
2022.04 130.8 131.7 84.1 (73.9 projected, +5.2) 11.79
2022.05 133.8 136.8 96.5 (80.3 projected, +6.4) 7.48
2022.06 116.1 119.8 70.5 (86.2 projected, +5.9) 8.20
2022.07 125.4 129.5 91.4 (93.4 projected, +7.2) 9.51
2022.08 114.2 117.1 75.4 (100.0 projected, +6.6) 10.92
2022.09 135.0 (1)   65.3 (2A) / 81.6 (2B) / 106.6 (2C) (104.9 projected, +4.9) (13.0)
2022.10       (108.1 projected, +3.2)  
2022.11       (110.9 projected, +2.8)  
2022.12       (115.7 projected, +4.8)  
2023.01       (121.7 projected, +6.0)  
2023.02       (126.7 projected, +5.0)  
2023.11       (142.5 projected max SC25)  

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: SIDC-SILSO.

Solar cycles 24-25

Smoothed SF and sunspot numbers

 

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.