Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 27, 2022 at 06:10 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 unsettled on September 26. Solar wind speed at SOHO ranged between 296 and 377 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. A strong disturbance, probably related to a CME that was observed on September 23 (at the time it wasn't considered to have an Earth directed component), began to influence the geomagnetic field late in the day. The disturbance intensified quickly early on September 27. While solar speed currently is still less than 450 km/sec, solar wind density was very high early on September 27. The total field of the interplanetary magnetic field appears to have peaked at an unusually high level of 31 nT at 04:29 UT. Unsettled to major storming is possible for the remainder of the day.

Solar flux density measured at 20h UT on 2.8 GHz was 135.1 - increasing 9.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 113.44). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 20011013 (planetary), 11012213 (Boulder), 31011015 (Andenes).

The background x-ray flux is at the class B9 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 7 active regions using 2K resolution (SN: 225) and in 7 active regions using 1K resolution (SN: 153) SDO/HMI images.

Region 13105 [S17W15] decayed slowly and quietly. New flux and a few spots emerged to the south of the largest trailing penumbra and in the central parts of the region.
Region 13107 [S24W01] decayed losing spots and area early in the day. After noon new flux emerged in the central parts with many new spots developing. An M class flare is possible. C1 flares: C1.4 @ 16:34, C1.8 @ 18:07, C1.4 @ 23:14 UT
Region 13108 [S13W51] decayed slowly and quietly.
Region 13109 [N09W69] decayed slowly and quietly.
Region 13110 [N16E30] decayed in the trailing and intermediate spot sections. C1 flares: C1.2 @ 14:46 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S7887 [N20W17] was quiet and stable.
New region S7892 [N28E82] rotated into view with a single mature spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.7/1F 09:11 S25E16 13107 GOES16  
C2.1 12:51   13107 GOES16  
C2.9 15:45 S23E06 13107 GOES16 simultaneous flare in AR 13110
C3.6 21:14   13107 GOES16  

Coronal mass ejections (CMEs)

September 24-26: 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) is expected to become Earth facing 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

Unsettled to major storm conditions are possible on September 27 due to CME effects. Quiet to unsettled is expected for September 28-29. Quiet to major storm conditions are likely on September 30 - October 2 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 43 23 S16W18 0150 DAI DAI

location: S17W15

area: 0120

13106 2022.09.19
2022.09.20
      S12W32        

location: S11W31

13108 2022.09.20
2022.09.21
7 16 5 S13W47 0050 CSO CRO location: S13W51
13107 2022.09.20
2022.09.21
33 62 33 S25E01 0220 ESI EAI beta-gamma

location: S24W01

13109 2022.09.21
2022.09.22
1 3 1 N10W66 0010 AXX BXO location: N09W69

area: 0007

13110 2022.09.22
2022.09.23
13 24 17 N15E35 0320 EHI ESI

location: N16E30

area: 0270

S7885 2022.09.23       N12W49            
S7886 2022.09.23       N30W24            
S7887 2022.09.23   6 3 N20W17 0013   BXO  
S7888 2022.09.24       N03W47            
S7889 2022.09.25       N34W52          
S7890 2022.09.25       S18W29          
S7891 2022.09.25       S12W05          
S7892 2022.09.26   1 1 N28E82 0170   HAX    
Total spot count: 70 155 83  
Sunspot number: 120 225 153  (total spot count + 10 * number of spotted regions)
Weighted SN: 95 188 106  (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): 132 124 122  

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)   72.5 (2A) / 83.7 (2B) / 107.3 (2C) (104.9 projected, +4.9) (12.4)
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.