Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 4, 2022 at 08:50 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 unsettled to minor storm on September 3 under the influence of a high speed stream from CH1097. Solar wind speed at SOHO ranged between 380 and 645 km/sec. The high latitude magnetometer at Andenes recorded unsettled to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 123.4 - increasing 7.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 110.27). The Potsdam WDC planetary A index was 24 (STAR Ap - based on the mean of three hour interval ap indices: 24.5). Three hour interval K indices: 53343335 (planetary), 54443323 (Boulder), 64344366 (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 8 active regions using 2K resolution (SN: 189) and in 6 active regions using 1K resolution (SN: 107) SDO/HMI images.

Region 13089 [S22W59] gained area and has a very large main penumbral area. Multiple magnetic delta structures are present, particularly in the western parts of the region. A major flare is possible. C1 flares: C1.1 @ 00:30, C1.1 @ 02:32, C1.7 @ 02:14, C1.2 @ 06:53, C1.2 @ 11:22, C1.1 @ 11:31, C1.3 @ 12:03, C1.3 @ 13:40, C1.0 @ 15:18, C1.0 @ 16:34, C1.0 @ 19:44, C1.2 @ 21:14 UT
Region 13092 [S10E40] gained tiny spots and was quiet. C1 flare: C1.0 @ 03:08 UT
Region 13093 [S27E30] gained spots and was quiet.
Region 13094 [N21E67] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S7822 [N20W08] was quiet and stable.
New region S7833 [N10E12] emerged with a tiny spot.
New region S7834 [S21E18] was observed with tiny spots in an old plage area.
New region S7835 [S16W41] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 07:11   13089 GOES16  
C2.0 08:21   13089 GOES16  
C2.1 12:26   13089 GOES16  
C3.1 16:48   13089 GOES16  
C2.6 20:17   13089 GOES16  
C2.8 21:36   13089 GOES16  
C2.1 23:09   13089 GOES16  
C2.1 23:18   13089 GOES16  
C4.0 00:06 (on Sept.4)   13089 GOES16  

Coronal mass ejections (CMEs)

September 1 and 3: No obviously Earth directed CMEs were observed.
September 2: A large filament eruption began at 17:06 UT in SDO/AIA imagery to the northwest of AR 13093 and eventually covered an area from east of AR 13093 in the southeast quadrant to center disk. The filament eruption apparently triggered a C3 flare in AR 13093 at 19:36 UT. A partial halo CME was observed after the filament eruption and a peripheral CME impact is possible on September 5.

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 trans equatorial coronal hole (CH1097) was Earth facing on August 31 - September 3.

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 to fair.

Forecast

Quiet to major storm conditions are likely on September 4-6, first due to effects from CH1097 then due to CME effects.

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
13090 2022.08.23
2022.08.25
      N16W62           location: N18W57
13089 2022.08.24 18 49 26 S22W61 0510 EKC EKC beta-gamma-delta

location: S22W59

area: 0880

S7816 2022.08.26       S13W28            
13091 2022.08.28
2022.09.01
      N14W46            
S7822 2022.08.28   4 1 N20W08 0007   BXO  
S7823 2022.08.29       N07W09            
S7824 2022.08.29       S12W29            
S7825 2022.08.30       S17W18            
13092 2022.08.31
2022.09.01
3 20 4 S10E38 0130 CSO CSO location: S10E40
S7827 2022.08.31       N26E17            
13093 2022.08.31
2022.09.02
4 23 10 S27E26 0030 BXO DRI area: 0040

location: S27E30

13094 2022.09.02
2022.09.02
3 6 3 N20E67 0100 CAO CAO  
S7831 2022.09.02       N24E16          
S7832 2022.09.02       S30E22          
S7833 2022.09.03   1   N10E12 0002   AXX    
S7834 2022.09.03   5 2 S21E18 0010   AXX    
S7835 2022.09.03   1   S16W41 0001   AXX    
Total spot count: 28 109 46  
Sunspot number: 68 189 106  (total spot count + 10 * number of spotted regions)
Weighted SN: 48 132 69  (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): 75 104 85  

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) 11.0
2022.09 123.2 (1)   6.9 (2A) / 68.7 (2B) / 98.9 (2C) (104.9 projected, +4.9) (13.4)
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.