Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 11, 2022 at 09:50 UT. The report covers September 9 data.

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 active on September 9. Solar wind speed at SOHO ranged between 388 and 551 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 126.2 - increasing 2.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 110.77). The Potsdam WDC planetary A index was 12 (STAR Ap - based on the mean of three hour interval ap indices: 12.3). Three hour interval K indices: 42343212 (planetary), 32353212 (Boulder), 62244314 (Andenes).

The background x-ray flux was at the class B7 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 242) and in 8 active regions using 1K resolution (SN: 121) SDO/HMI images.

Region 13092 [S10W39] was quiet and stable.
Region 13094 [N21W11] decayed slowly and quietly.
Region 13096 [N18E33] produced a few C flares early in the day. Some penumbral area was lost. C1 flare: C1.2 @ 01:36 UT.
Region 13097 [S11W27] was mostly quiet and stable. C1 flare: C1.1 @ 15:39 UT.
Region 13098 [N18E04] lost some area and a few spots. C1 flares: C1.1 @ 21:05 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S7842 [S24E29] lost the leader spots and was quiet.
S7843 [N13E39] gained a few spots and was mostly quiet. C1 flare: C1.0 @ 01:28 UT.
S7850 [S23E65] developed slowly and quietly.
New region S7852 [N13E48] emerged with several spots.
New region S7853 [S04W17] emerged with a tiny spot.
New region S7854 [S16E27] emerged with tiny spots.
New region S7855 [N28W50] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 02:13   13096 GOES16  

Coronal mass ejections (CMEs)

September 7-9: 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 northern hemisphere coronal hole (CH1098) will likely become Earth facing on September 10.

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 on September 10-12. Quiet to unsettled conditions are possible on September 13-14 due to effects from CH1098.

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
1 9 2 S10W40 0050 HSX CAO location: S10W39

area: 0090

13093 2022.08.31
2022.09.02
      S26W53        

location: S29W46

13094 2022.09.02
2022.09.02
1 15 4 N18W12 0010 AXX CRI location: N21W11

area: 0030

S7831 2022.09.02       N28W59            
S7832 2022.09.02       S30W56            
S7838 2022.09.04       N17W31            
13097 2022.09.05
2022.09.07
3 10 5 S11W25 0010 BXO BXO area: 0020

location: S11W27

S7840 2022.09.05       N17W09            
13096 2022.09.05
2022.09.06
9 25 10 N16E33 0130 DAI DAI

location: N18E33

S7842 2022.09.05   3   S24E29 0003   AXX  
S7843 2022.09.06   10 3 N13E39 0020   BXO  
13098 2022.09.06
2022.09.08
8 29 10 N17E05 0020 CRO DRI area: 0080

location: N18E04

S7845 2022.09.06       S09E18            
S7846 2022.09.07       S19W59            
S7847 2022.09.07       N32W37            
S7848 2022.09.07       S24W09            
S7849 2022.09.08       N15W25          
S7850 2022.09.08   7 4 S23E65 0040   CRO  
S7851 2022.09.08       S27W35          
S7852 2022.09.09   7 3 N13E48 0030   DRI    
S7853 2022.09.09   1   S04E17 0002   AXX    
S7854 2022.09.09   3   S16E27 0005   BXO    
S7855 2022.09.09   3   N28W50 0003   BXO    
Total spot count: 22 122 41  
Sunspot number: 72 242 121  (total spot count + 10 * number of spotted regions)
Weighted SN: 35 144 63  (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): 79 133 97  

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
2022.09 125.9 (1)   20.8 (2A) / 69.2 (2B) / 103.8 (2C) (104.9 projected, +4.9) (22.4)
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.