Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 28, 2022 at 06:15 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 minor storm on September 27. Solar wind speed at SOHO ranged between 356 and 741 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels. The source of the disturbance is uncertain, but may involve one of the CMEs observed on September 23 and a high speed stream associated with CH1102. The total field of the IMF reached 31 nT, which is a level usually only observed with major CME disturbances. The Bz component was mostly northwards during the day which resulted in a weaker than expected geomagnetic disturbance.

Solar flux density measured at 20h UT on 2.8 GHz was 134.5 - increasing 21.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 113.57). The Potsdam WDC planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.4). Three hour interval K indices: 54243223 (planetary), 54232223 (Boulder), 65234325 (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 5 active regions using 2K resolution (SN: 157) and in 4 active regions using 1K resolution (SN: 100) SDO/HMI images.

Region 13105 [S17W30] produced a few flares and has polarity intermixing. C1 flares: C1.1 @ 14:48, C1.3 @ 14:59 UT
Region 13107 [S24W13] developed a magnetic delta in a central penumbra. M class flaring is possible.
Region 13108 [S13W66] decayed slowly and quietly.
Region 13110 [N16E17] was quiet and stable.
New region 13111 [N28E69] rotated into view on September 26 and was numbered by SWPC the next day.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.8 04:24 S25W04 13107 GOES16  
C4.0 04:36 S24W06 13107 GOES16  
C2.3 06:04   13107 GOES16  
C4.8 06:46 S25W04 13107 GOES16  
C4.0 11:56 S25W03 13107 GOES16  
C2.1 13:52 S25W07 13107 GOES16  
C2.0 16:50 S16W29 13105 GOES16  
C5.0 19:57 S15W30 13105 GOES16  
C2.2 23:07   13105 GOES16  

Coronal mass ejections (CMEs)

September 25-27: 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 trans equatorial coronal hole (CH1103) will be Earth facing on September 27-30.

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 unsettled conditions are expected for September 28-29. Quiet to major storm conditions are likely on September 30 - October 3 due to effects from CH1103.

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
13105 2022.09.19
2022.09.19
16 30 18 S16W30 0120 CAI DAI

location: S17W30

13106 2022.09.19
2022.09.20
      S12W46          

location: S11W44

13108 2022.09.20
2022.09.21
2 3   S13W65 0010 BXO BXO location: S13W66

area: 0003

13107 2022.09.20
2022.09.21
27 51 28 S24W13 0200 EAI EAC beta-gamma-delta
13109 2022.09.21
2022.09.22
      N10W80         location: N09W82
13110 2022.09.22
2022.09.23
14 22 13 N15E20 0220 CAI ESO

location: N16E17

S7886 2022.09.23       N30W37            
S7887 2022.09.23       N20W30          
S7890 2022.09.25       S18W42            
S7891 2022.09.25       S12W18            
13111 2022.09.26
2022.09.27
1 1 1 N27E68 0100 HAX HSX area: 0170

location: N28E69

Total spot count: 60 107 60  
Sunspot number: 110 157 100  (total spot count + 10 * number of spotted regions)
Weighted SN: 80 127 80  (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): 121 86 80  

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
2022.09 134.9 (1)   76.2 (2A) / 84.6 (2B) / 106.7 (2C) (104.9 projected, +4.9) (12.7)
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.