Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 11, 2023 at 11:15 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 very quiet on June 10. Solar wind speed at SOHO ranged between 305 and 355 km/sec. The high latitude magnetometer at Andenes recorded quiet  levels. A co-rotating interaction region associated with CH1152 was observed beginning at DSCOVR at 22:52 UT and cause unsettled conditions early on June 11.

Solar flux density measured at 20h UT on 2.8 GHz was 161.2 - increasing 20.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.32. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.9). Three hour interval K indices: 11000121 (planetary), 11111221 (Boulder), 33101232 (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 17 active regions using 2K resolution (SN: 374) and in 12 active regions using 1K resolution (SN: 202) SDO/HMI images.

Region 13321 [S15W76] was quiet and stable.
Region 13323 [S08W61] decayed further and has only tiny spots remaining, however, the region was unstable and managed to produce a number of C flares. C1 flares: C1.1 @ 01:03, C1.2 @ 02:20, C1.1 @ 02:33, C1.5 @ 03:32, C1.0 @ 10:57 UT
Region 13326 [N25W27] was quiet and stable.
Region 13327 [S14W11] lost mature penumbra and has many small and tiny spots. The region has polarity intermixing and could produce C and minor M class flares. C1 flares: C1.2 @ 07:05, C1.0 @ 15:05, C1.3 @ 15:34, C1.2 @ 15:39, C1.2 @ 16:47, C1.9 @ 22:09, C1.8 @ 23:25 UT
Region 13329 [N23W11] displayed signs of decay with the largest penumbra fragmenting.
Region 13330 [N17W28] developed slowly and quietly.
Region 13331 [S22E28] was quiet and stable.
Region 13332 [S08E32] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8629 [N12E06] was mostly quiet and stable. C1.2 @ 18:22 UT
S8639 [S12E65] was quiet and stable
New region S8642 [S16E23] emerged with a tiny spot.
New region S8644 [N31W24] emerged with a few spots.
New region S8645 [S23E09] emerged with tiny spots.
New region S8646 [S30E77] rotated into view with tiny spots.
New region S8647 [S28W24] was observed with tiny spots in an old plage area.
New region S8648 [S42W12] emerged with a tiny spot.
New region S8649 [S20E70] rotated into view with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.5 18:51   13327 GOES16  
C3.8 21:06   13323 GOES16  
C5.7 21:16   13323 GOES16  

Coronal mass ejections (CMEs)

June 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 (CH1152) was Earth facing on June 6-8. A recurrent trans equatorial coronal hole (CH1153) will likely 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 to unsettled conditions are likely on June 11 due to effects from CH1152. Quiet conditions are likely on June 12-14. Quiet to active condition 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
13320 2023.05.28
2023.05.29
      N10W89          
13321 2023.05.29
2023.05.30
1 1 1 S16W79 0150 HSX HHX

area: 0260

location: S15W76

13323 2023.05.30
2023.05.31
6 9 3 S08W61 0010 BXO BXO

area: 0015

13326 2023.06.02
2023.06.02
1 6 3 N26W29 0080 HSX CSO location: N25W27

area: 0140

S8617 2023.06.02       N10W26          
13327 2023.06.03
2023.06.04
30 89 37 S15W13 0110 EAI ERI beta-gamma

area: 0190

location: S14W11

S8625 2023.06.03       S23W47            
13328 2023.06.04
2023.06.05
      N11W73          

location: N09W68

S8629 2023.06.04   17 3 N12E06 0030   BXO  
13330 2023.06.05
2023.06.06
  13 6 N18W31 0030   BXO

location: N17W28

13329 2023.06.05
2023.06.06
5 23 13 N23W12 0120 CAO DAO location: N23W11

area: 0150

13331 2023.06.06
2023.06.07
2 19 8 S22E25 0170 EAO EAO area: 0310

location: S22E28

S8634 2023.06.07       S00W32            
13332 2023.06.07
2023.06.07
1 4 2 S08E31 0000 AXX CRO area: 0020
S8636 2023.06.07       N23E21            
S8637 2023.06.09       N07W34            
S8638 2023.06.09       N30W26            
S8639 2023.06.09   7 2 S12E65 0030   CRO  
S8640 2023.06.09       N12E24          
S8641 2023.06.09       S11E04          
S8642 2023.06.10   1 1 S16E23 0004   AXX    
S8644 2023.06.10   5 3 N31W24 0020   CRO    
S8645 2023.06.10   4   S23E09 0005   BXO    
S8646 2023.06.10   2   S30E77 0002   AXX    
S8647 2023.06.10   2   S28W24 0005   AXX    
S8648 2023.06.10   1   S42W12 0001   AXX    
S8649 2023.06.10   1   S20E70 0002   AXX    
Total spot count: 46 204 82  
Sunspot number: 116 374 202  (total spot count + 10 * number of spotted regions)
Weighted SN: 71 241 119  (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): 128 206 162  

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
2023.06 166.1 (1)   46.3 (2A) / 139.0 (2B) / 162.1 (2C) (134.3 projected, +3.1) (5.0)
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.