Solar Terrestrial Activity Report

Activity chart

Last major update issued on September 11, 2022 at 13:30 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 10. Solar wind speed at SOHO ranged between 382 and 527 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 135.9 - increasing 10.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 110.88). 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: 32323332 (planetary), 32323332 (Boulder), 42234454 (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 15 active regions using 2K resolution (SN: 310) and in 11 active regions using 1K resolution (SN: 173) SDO/HMI images.

Region 13092 [S09W52] was quiet and stable.
Region 13094 [N20W24] decayed slowly and quietly.
Region 13096 [N18E20] decayed slowly and quietly losing all mature penumbra.
Region 13097 [S11W40] decayed slowly and quietly.
Region 13098 [N19W10] developed gaining spots and area despite splitting off AR S7858. C1 flares: C1.2 @ 07:03, C1.1 @ 07:21 UT
New region 13099 [N12E32] emerged on September 9 and was numbered by SWPC the following day later as the region began to decay.13101
New region 13100 [S24E51] rotated into view on September 8 and was numbered by SWPC 2 days later as the region gained spots and area. The region has polarity intermixing and a minor M class flare is possible. C1 flares: C1.0 @ 02:09, C1.2 @ 07:46, C1.6 @ 21:57 UT
New region 13101 [N29W55] emerged with many small spots. C flares are possible.

Spotted regions not observed (or interpreted differently) by SWPC:
S7842 [S25E07] was quiet and stable as a leader spot reemerged.
S7843 [N12E26] decayed slowly and quietly.
New region S7857 [N23W06] emerged to the north of AR 13098 and caused parts of CH1098 to close.
New region S7858 [N15W08] was split off from AR 13098.
New region S7859 [N19W43] emerged with tiny spots.
New region S7860 [S17E74] rotated into view with tiny spots. C1 flare: C1.9 @ 09:02 UT
New region S7861 [S02E33] emerged near equator with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6/1F 11:19 S23E60 13100 GOES16  
C2.2 21:57   13100 GOES16  
C2.8 00:09 (on Sept.11)   13100 GOES16  

Coronal mass ejections (CMEs)

September 8-10: 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) was Earth facing on September 10. Another northern hemisphere coronal hole (CH1099) will likely rotate across the central meridian on September 13-14.

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 11-12. 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 8 2 S09W54 0060 HSX CSO location: S09W52

area: 0090

13093 2022.08.31
2022.09.02
      S26W67          

location: S29W59

13094 2022.09.02
2022.09.02
1 11 3 N20W27 0010 AXX BXO location: N20W24

area: 0030

13097 2022.09.05
2022.09.07
3 5 2 S11W39 0010 BXO BXO area: 0013

location: S11W40

S7840 2022.09.05       N17W22            
13096 2022.09.05
2022.09.06
7 25 8 N16E19 0100 DAO DRI

location: N18E20

area: 0070

S7842 2022.09.05   4   S25E07 0006   BXO  
S7843 2022.09.06   9 3 N12E26 0015   BXO  
13098 2022.09.06
2022.09.08
12 31 17 N18W08 0060 CAO DRI area: 0120

location: N19W10

S7845 2022.09.06       S09E05            
S7847 2022.09.07       N32W50            
S7848 2022.09.07       S24W22            
S7849 2022.09.08       N15W38            
13100 2022.09.08
2022.09.10
11 20 8 S25E48 0070 CSI EAI beta-gamma

location: S24E51

area: 0120

S7851 2022.09.08       S27W48            
13099 2022.09.09
2022.09.10
2 5 1 N12E32 0020 CRO CRO  
S7853 2022.09.09       S04E04          
S7854 2022.09.09       S16E14          
13101 2022.09.10
2022.09.10
5 19 9 N29W57 0010 BXO CRI   was AR S7856

area: 0050

location: N29W55

S7857 2022.09.10   5 3 N23W06 0020   CRO    
S7858 2022.09.10   12 7 N15W08 0025   DRO   split off from AR 13098
S7859 2022.09.10   2   N19W43 0002   BXO    
S7860 2022.09.10   3   S17E74 0005   BXO    
S7861 2022.09.10   1   S02E33 0001   AXX    
Total spot count: 42 160 63  
Sunspot number: 122 310 173  (total spot count + 10 * number of spotted regions)
Weighted SN: 65 188 91  (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): 134 171 138  

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
2022.09 126.9 (1)   24.8 (2A) / 74.5 (2B) / 104.5 (2C) (104.9 projected, +4.9) (21.4)
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.