Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 8, 2022 at 03:40 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 7 under the weakening influence of a high speed stream from CH1097. Solar wind speed at SOHO ranged between 508 and 677 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 126.1 - increasing 11.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 110.63). The Potsdam WDC planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 13.0). Three hour interval K indices: 32333331 (planetary), 23433331 (Boulder), 53333643 (Andenes).

The background x-ray flux is at the class B6 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 193) and in 11 active regions using 1K resolution (SN: 156) SDO/HMI images.

Region 13092 [S10W12] decayed slowly and was quiet.
Region 13094 [N19E14] decayed slowly and was mostly quiet. C1 flare: C1.0 @ 22:48 UT
Region 13096 [N18E59] developed further and produced a few minor C flares. C1 flares: C1.0 @ 15:54, C1.0 @ 17:15, C1.1 @ 18:04, C1.1 @ 23:53 UT
New region 13097 [S11E02] emerged on September 5 and was numbered by SWPC 2 days later.

Spotted regions not observed (or interpreted differently) by SWPC:
S7840 [N17E17] decayed slowly and quietly.
S7842 [S24E46] decayed slowly and quietly.
S7843 [N13E64] was quiet and stable.
S7844 [N17E32] was quiet and stable.
New region S7846 [S19W33] emerged with a tiny spot.
New region S7847 [N32W11] emerged with a tiny spot.
New region S7848 [S24E17] emerged with tiny spots.

AR 13089 behind the southwest limb was the likely source of a C1.4 flare at 01:41 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
           

Coronal mass ejections (CMEs)

September 5-7: 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 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 unsettled is expected on September 8 due to lingering effects from CH1097. Quiet conditions are likely on September 9-10.

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
13092 2022.08.31
2022.09.01
3 10 3 S16W14 0150 HSX CSO location: S10W12

area: 0130

S7827 2022.08.31       N26W35            
13093 2022.08.31
2022.09.02
1     S26W25 0000 AXX    

spotless

location: S27W22

13094 2022.09.02
2022.09.02
8 18 8 N21E12 0030 CSO CRO location: N19E14

area: 0050

S7831 2022.09.02       N28W33            
S7832 2022.09.02       S30W30            
S7833 2022.09.03       N10W40            
S7834 2022.09.03       S21W31            
13095 2022.09.04
2022.09.05
      S14W73           location: S13W68
S7838 2022.09.04       N17W05            
13097 2022.09.05
2022.09.07
5 17 10 S12E01 0020 DSO DRO area: 0060

location: S11E02

S7840 2022.09.05   2 1 N17E17 0006   HRX  
13096 2022.09.05
2022.09.06
6 16 12 N18E57 0040 DSO DAI area: 0130

location: N18E59

S7842 2022.09.05   1 1 S24E46 0002   AXX  
S7843 2022.09.06   4 2 N13E64 0012   HRX  
S7844 2022.09.06   11 6 N17E32 0025   BXO  
S7845 2022.09.06       S09E44          
S7846 2022.09.07   1 1 S19W33 0004   AXX    
S7847 2022.09.07   1 1 N32W11 0005   AXX    
S7848 2022.09.07   2 1 S24E17 0003   AXX    
Total spot count: 23 83 46  
Sunspot number: 73 193 156  (total spot count + 10 * number of spotted regions)
Weighted SN: 43 105 68  (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): 80 106 125  

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
2022.09 125.8 (1)   15.9 (2A) / 68.0 (2B) / 102.6 (2C) (104.9 projected, +4.9) (24.2)
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.