Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 12, 2023 at 03:55 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 (June 1, 2023)
Solar cycle Solar cycles 23-25 (June 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (June 1, 2023) 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 (June 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (June 1, 2023) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (May 29, 2023) 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 June 11 under the influence of weak effects from CH1152. Solar wind speed at SOHO ranged between 339 and 454 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 153.8 - increasing 19.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.58. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 23222312 (planetary), 33323312 (Boulder), 22223432 (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 14 active regions using 2K resolution (SN: 301) and in 12 active regions using 1K resolution (SN: 197) SDO/HMI images.

Region 13323 [S08W72] decayed slowly and was mostly quiet.
Region 13326 [N25W40] was quiet and stable.
Region 13327 [S15W25] decayed losing spots and area. The region produced only a few low level C flares. C1 flares: C1.3 @ 04:28, C1.7 @ 04:50, C1.8 @ 05:39, C1.7 @ 14:44 UT
Region 13329 [N22W25] decayed slowly and quietly.
Region 13330 [N17W42] was quiet and stable.
Region 13331 [S22E13] gained spots and was mostly quiet. C1 flares: C1.2 @ 08:15, C1.4 @ 17:13 UT
Region 13332 [S08E19] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8617 [N11W41] reemerged with a tiny spot.
S8629 [N10W06] was quiet and stable.
S8636 [N23E08] reemerged with tiny spots.
S8639 [S12E51] was quiet and stable
S8645 [S27W04] was quiet and stable.
New region S8651 [S11E41] emerged with tiny spots.
New region S8652 [N18E67] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.8 02:02 S06W72 13323 GOES16  
C3.3 06:31   13323 GOES16 incorrectly attributed to AR 13321 by SWPC
C2.1 15:02   13327 GOES16  
C2.0 16:09   13321 GOES16  
C2.0 18:53 behind SE limb   GOES16 LDE

Coronal mass ejections (CMEs)

June 9-11: 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 (CH1152) was Earth facing on June 6-8. A recurrent trans equatorial coronal hole (CH1153) will rotate across the central meridian on June 12-13.

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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are likely on June 12-14. Quiet to active conditions are expected for June 15-16 due to effects from CH1153.

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
13321 2023.05.29
2023.05.30
1     S15W91 0090 HSX     rotated out of view
13323 2023.05.30
2023.05.31
  2 1 S10W78 0005   BXO

 

13326 2023.06.02
2023.06.02
3 5 1 N25W42 0120 HSX CSO location: N25W40

area: 0130

S8617 2023.06.02   1 1 N11W41 0002   AXX    
13327 2023.06.03
2023.06.04
37 63 38 S16W27 0130 EAI ERI beta-gamma

location: S15W25

13328 2023.06.04
2023.06.05
      N11W87          

location: N09W81

S8629 2023.06.04   16 1 N10W06 0025   BXO  
13330 2023.06.05
2023.06.06
  12 4 N18W45 0020   BXO

location: N17W42

13329 2023.06.05
2023.06.06
7 11 4 N23W24 0110 CAO CAO location: N22W25
13331 2023.06.06
2023.06.07
7 31 19 S22E13 0170 EAO ESI area: 0240
S8634 2023.06.07       S00W45            
13332 2023.06.07
2023.06.07
1 2 1 S08E17 0010 AXX CRO location: S08E19
S8636 2023.06.07   5   N23E08 0007   BXO    
S8637 2023.06.09       N07W47            
S8638 2023.06.09       N30W39            
S8639 2023.06.09   8 5 S12E51 0025   CRO  
S8640 2023.06.09       N12E11            
S8641 2023.06.09       S11W09            
S8642 2023.06.10       S16E10          
S8644 2023.06.10       N31W37          
S8645 2023.06.10   2 1 S27W04 0005   BXO  
S8646 2023.06.10       S30E64          
S8647 2023.06.10       S28W37          
S8648 2023.06.10       S42W25          
S8649 2023.06.10       S20E57          
S8651 2023.06.11   2 1 S11E41 0004   BXO    
S8652 2023.06.11   1   N18E67 0001   AXX    
Total spot count: 56 161 77  
Sunspot number: 116 301 197  (total spot count + 10 * number of spotted regions)
Weighted SN: 81 185 101  (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): 128 166 158  

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 (SC24 solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(SC24 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
2021.10 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 64.7 (+4.6) 10.46
2022.03 117.0 115.8 78.6 68.7 (+4.0) 10.20
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.4 (+4.4) 7.48
2022.06 116.1 119.8 70.3 81.1 (+3.7) 8.20
2022.07 125.4 129.5 91.4 86.7 (+5.6) 9.51
2022.08 114.2 117.1 74.6 92.5 (+5.8) 10.92
2022.09 135.1 136.5 96.0 96.4 (+3.9) 12.18
2022.10 133.5 132.7 95.5 98.7 (+2.3) 11.16
2022.11 123.4 120.7 80.5 101.0 (+2.3) 9.33
2022.12 147.9 143.4 112.8 (105.8 projected, +4.8) 10.99
2023.01 182.4 176.6 143.6 (112.2 projected, +6.4) 8.73
2023.02 167.2 163.2 110.9 (117.0 projected, +4.8) 14.48
(current
SC25 peak)
2023.03 157.2 155.6 122.6 (120.1 projected, +3.1) 14.42
2023.04 145.4 146.4 96.4 (125.5 projected, +5.4) 13.40
2023.05 155.6 159.2 137.9 (131.2 projected, +5.7) 10.9
2023.06 165.0 (1)   50.2 (2A) / 136.9 (2B) / 162.3 (2C) (134.3 projected, +3.1) (5.3)
2023.07       (133.8 projected, -0.5)  
2023.08       (134.8 projected, +1.0)  
2023.09       (138.2 projected, +3.4)  
2023.10       (140.1 projected, +1.9)  
2023.11       (142.7 projected max SC25)  
2023.12       (142.6 projected, -0.1)  

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: WDC-SILSO, Royal Observatory Of Belgium, Brussels

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.