Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 5, 2022 at 10:35 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 (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 minor to major storm on September 4 under the influence of a high speed stream from CH1097. Solar wind speed at SOHO ranged between 548 and 748 km/sec. The high latitude magnetometer at Andenes recorded active to severe storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 128.3 - increasing 15.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 110.38). The Potsdam WDC planetary A index was 62 (STAR Ap - based on the mean of three hour interval ap indices: 62.3). Three hour interval K indices: 56665655 (planetary), 55564534 (Boulder), 76655746 (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 11 active regions using 2K resolution (SN: 205) and in 9 active regions using 1K resolution (SN: 144) SDO/HMI images.

Region 13089 [S22W72] lost some area as it approached the southwest limb. Fewer magnetic delta structures were observed as well, however, there is still a chance of a major flare. C1 flares: C1.9 @ 11:16, C1.9 @ 14:55, C1.8 @ 18:06, C1.8 @ 22:52 UT
Region 13092 [S10E27] was mostly quiet and stable.
Region 13093 [S27E18] decayed slowly and was mostly quiet.
Region 13094 [N20E53] was mostly quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S7821 [N18W53] reemerged with a tiny spot.
S7822 [N21W21] developed slowly and quietly.
S7831 [N26E18] reemerged with tiny spots.
S7834 [S21E08] was quiet and stable.
New region S7836 [S13W30] emerged with a few spots.
New region S7837 [N24W35] emerged with a tiny spot.
New region S7838 [N15E40] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 01:32   13094 GOES16  
C6.4 03:02 S23W61 13089 GOES16  
C5.1 04:05   13089 GOES16  
C4.8/1F 05:31 S24W62 13089 GOES16  
C2.2 07:17   13094 GOES16  
C3.9 07:54   13093 GOES16  
C2.8 08:34   13093 GOES16  
C2.0 08:56   13093 GOES16  
C2.3 10:21 S24W62 13089 GOES16  
C2.5 10:55   13089 GOES16  
C3.1 11:32   13089 GOES16  
C3.0 11:46   13089 GOES16  
C4.3 12:16   13089 GOES16  
C3.3 12:27   13089 GOES16  
C2.2 13:08 behind southeast limb?   GOES16  
C2.5 13:55   13089 GOES16  
C2.9 14:10   13089 GOES16  
C2.1 15:04   13089 GOES16  
C2.1 16:23   13089 GOES16  
C8.2/1N 16:38   13089 GOES16  
C2.2 18:27   13089 GOES16  
C2.1 19:29   13089 GOES16  
C2.0 20:24   13089 GOES16  
C2.3 20:51   13089 GOES16  
C2.5 21:48   13089 GOES16  

Coronal mass ejections (CMEs)

September 3-4: 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 to very poor. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

Quiet to major storm conditions are likely on September 5-6, first due to effects from CH1097 then due to CME effects. Quiet to unsettled is expected on September 7-8.

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
      N16W76           location: N18W70
13089 2022.08.24 13 31 19 S23W74 0520 EKC EKC beta-gamma-delta

location: S22W72

area: 0800

S7816 2022.08.26       S13W41            
13091 2022.08.28
2022.09.01
      N14W60            
S7821 2022.08.28   2   N18W53 0002   BXO    
S7822 2022.08.28   11 8 N21W21 0025   BXO  
S7823 2022.08.29       N07W22            
S7824 2022.08.29       S12W42            
S7825 2022.08.30       S17W31            
13092 2022.08.31
2022.09.01
3 18 7 S10E27 0090 CSO CSO  
S7827 2022.08.31       N26E04            
13093 2022.08.31
2022.09.02
3 13 8 S27E16 0030 CRO DRO

location: S27E18

13094 2022.09.02
2022.09.02
3 6 3 N21E53 0100 CAO CAO  
S7831 2022.09.02   2   N26E18 0004   AXX    
S7832 2022.09.02       S30E09            
S7833 2022.09.03       N10W01          
S7834 2022.09.03   2 1 S21E08 0005   AXX  
S7835 2022.09.03       S16W54          
S7836 2022.09.04   7 5 S13W30 0025   DRO    
S7837 2022.09.04   1 1 N24W35 0002   AXX    
S7838 2022.09.04   2 2 N15E40 0005   BXO    
Total spot count: 22 95 54  
Sunspot number: 62 205 144  (total spot count + 10 * number of spotted regions)
Weighted SN: 45 121 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): 68 113 115  

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
2022.09 124.5 (1)   8.9 (2A) / 67.0 (2B) / 99.9 (2C) (104.9 projected, +4.9) (25.6)
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.