Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 8, 2023 at 03:25 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 on June 7. Solar wind speed at SOHO ranged between 324 and 393 km/sec. The high latitude magnetometer at Andenes recorded quiet levels. A very weak disturbance, probably CME related, was observed arriving at DSCOVR near 22:24 UT.

Solar flux density measured at 20h UT on 2.8 GHz was 167.2 - increasing 3.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 142.96. 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: 3.0). Three hour interval K indices: 10011012 (planetary), 11011323 (Boulder), 10111221 (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 18 active regions using 2K resolution (SN: 416) and in 15 active regions using 1K resolution (SN: 249) SDO/HMI images.

Region 13320 [N10W49] decayed slowly and quietly.
Region 13321 [S15W37] was quiet and stable.
Region 13323 [S08W18] decayed further and was mostly quiet. C1 flares: C1.7 @ 03:47, C1.6 @ 04:07 UT
Region 13324 [N14W78] developed slowly and quietly.
Region 13326 [N25E12] was quiet and stable.
Region 13327 [S14E29] developed slowly, has many spots and several small magnetic delta configurations. Further M class activity is likely. C1 flares: C1.3 @ 03:02 UT
Region 13328 [N09W29] was quiet and stable.
Region 13329 [N23E29] matured and was mostly quiet. C1 flares: C1.5 @ 00:20, C1.9 @ 03:40, C1.8 @ 22:05 UT
Region 13330 [N17E12] decayed slowly and quietly.
New region 13331 [S22E66] rotated into view on June 6 and was numbered by SWPC the next day. The region has mature spots and appears to be stable.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8606 [N11W42] reemerged with tiny spots.
S8610 [N29W35] was quiet and stable.
S8617 [N10E11] was quiet and stable.
S8625 [S23W08] was quiet and stable.
S8629 [N10E46] was quiet and stable.
New region S8634 [S00E07] emerged with a tiny spot.
New region S8635 [S08E76] rotated into view with a tiny spot.
New region S8636 [N23E55] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C7.1 06:45 S17E42 13327 GOES16 CME in conjunction with filament eruption
C3.3 07:25   13327 GOES16  
C2.7 09:10   13327 GOES16  
C2.3 09:40   13327 GOES16  
M4.7 11:46   13327 GOES16  
C3.7 14:20   13327 GOES16  
C3.6 14:43   13327 GOES16  
C2.0 15:26   13323 GOES16  
C2.1 15:55   13331 GOES16  
C8.7/1N 18:29 S17E34 13327 GOES16  
C9.2 18:35   13327 GOES16  
C7.0 18:50   13327 GOES16  

Coronal mass ejections (CMEs)

June 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 northern hemisphere coronal hole (CH1152) will be Earth facing on June 6-8.

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 8. Quiet to active condition are possible on June 9-11 due to effects from CH1152.

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
1 4 1 N10W48 0010 HRX HRX area: 0025
13321 2023.05.29
2023.05.30
3 18 7 S14W39 0200 CSO CHO

area: 0320

S8606 2023.05.29   3 1 N11W42 0010   BXO    
S8610 2023.05.30   2   N29W35 0002   AXX  
13324 2023.05.30
2023.06.02
2 7 4 N15W77 0040 BXO CRO location: N14W78
13323 2023.05.30
2023.05.31
30 72 35 S08W20 0150 EAI EAI

beta-gamma

location: S08W18

S8613 2023.06.01       S08W48            
13325 2023.06.01
2023.06.02
1     N12W74 0010 AXX     location: N09W72

not sure what SWPC observed

13326 2023.06.02
2023.06.02
1 11 1 N25E11 0060 HSX CSO location: N25E12

area: 0140

S8617 2023.06.02   2 1 N10E11 0007   BXO  
13327 2023.06.03
2023.06.04
28 69 41 S16E28 0250 EKI EAC beta-gamma-delta

area: 0340

S8623 2023.06.03       N15W27            
S8624 2023.06.03       S03W59            
S8625 2023.06.03   3 2 S23W08 0007   AXX  
13328 2023.06.04
2023.06.05
  2   N11W31 0004   AXX

location: N09W29

S8629 2023.06.04   4 2 N10E46 0010   BXO  
13330 2023.06.05
2023.06.06
2 13 5 N18E14 0020 DRO CRO

location: N17E12

13329 2023.06.05
2023.06.06
7 17 13 N23E28 0120 DAO DSO location: N23E29

area: 0280

13331 2023.06.06
2023.06.07
2 5 4 S22E62 0140 HAX EHO area: 0410

location: S22E66

S8633 2023.06.06       S23W49          
S8634 2023.06.07   1   S00E07 0002   AXX    
S8635 2023.06.07   1 1 S08E76 0003   AXX    
S8636 2023.06.07   2 1 N23E55 0003   BXO    
Total spot count: 77 236 119  
Sunspot number: 177 416 249  (total spot count + 10 * number of spotted regions)
Weighted SN: 118 285 168  (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): 195 229 199  

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
2023.06 166.8 (1)   32.4 (2A) / 139.0 (2B) / 163.5 (2C) (134.3 projected, +3.1) (5.6)
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.