Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 14, 2023 at 07:45 UT. The update for June 14 will not be posted until after 15h 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 13. Solar wind speed at SOHO ranged between 377 and 493 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.

Solar flux density measured at 20h UT on 2.8 GHz was 146.3 - increasing 8.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.69. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 11121211 (planetary), 32222322 (Boulder), 21122323 (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 13 active regions using 2K resolution (SN: 229) and in 12 active regions using 1K resolution (SN: 171) SDO/HMI images.

Region 13326 [N25W67] was mostly quiet and stable. C1 flares: C1.8 @ 15:14 UT
Region 13327 [S15W51] decayed slowly and was mostly quiet. C1 flares: C1.3 @ 06:01
Region 13329 [N23W51] was mostly quiet and stable. C1 flares: C1.3 @ 02:16 UT
Region 13331 [S23W12] developed a magnetic delta configuration in the central spot section. There is a slight chance of an M class flare.
New region 13333 [S11E50] emerged on June 12 and was numbered the next day by SWPC as the region developed fairly quickly. A magnetic delta configuration appears to be forming and an M class flare is possible. C1 flares: C1.7 @ 11:04, C1.7 @ 23:05 UT
New region 13334 [N17E76] rotated into view with a few spots. C1 flares: C1.7 @ 08:44, C1.3 @ 14:18 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8629 [N10W30] decayed slowly and quietly.
S8639 [S12E26] was quiet and stable.
S8651 [S12E14] was quiet and stable.
New region S8655 [S21E79] rotated into view with several spots. M class flares are possible. C1 flares: C1.8 @ 20:05, C1.5 @ 20:50 UT
New region S8657 [N20W04] emerged with tiny spots.
New region S8658 [S14E78] rotated into view with tiny spots.
New region S8659 [S13E01] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 08:19   13334 GOES16 simultaneous flare in AR 13333
C2.0 10:20   13334 GOES16  
C2.1 10:26   13334 GOES16  
C4.9 12:07   S8655 GOES16 incorrectly attributed to AR 13329 by SWPC
C2.1 12:45   13333 GOES16  
C2.0 14:34   S8655 GOES16  
C6.3/1F 17:38 N16E73 13334 GOES16 CME, weak type II radio sweep
C2.1 19:36   S8655 GOES16  
C2.0 20:12   S8655 GOES16  
C2.1/1F 20:26   S8655 GOES16  
C3.8 20:31   S8655 GOES16  
C2.2 22:20   S8658 GOES16  
C2.0 23:36   S8655 GOES16  
C2.1 23:45   S8655 GOES16  

Coronal mass ejections (CMEs)

June 11-13: 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 recurrent trans equatorial coronal hole (CH1153) rotate across the central meridian on June 12-14.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are likely on June 14. Quiet to active conditions are expected for June 15-17 due to effects from CH1153, isolated minor storm intervals are possible.

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
13326 2023.06.02
2023.06.02
1 1 1 N26W67 0050 HSX HSX location: N25W67

area: 0120

13327 2023.06.03
2023.06.04
12 13 5 S15W53 0010 BXO BXO

location: S15W51

S8629 2023.06.04   3   N10W30 0006   AXX  
13330 2023.06.05
2023.06.06
      N18W73        

location: N17W71

13329 2023.06.05
2023.06.06
2 10 5 N23W52 0090 HSX CAO location: N23W51
13331 2023.06.06
2023.06.07
10 20 9 S23W14 0120 DAO DAC beta-delta

area: 0160

13332 2023.06.07
2023.06.07
      S08W08        

 

S8636 2023.06.07       N27W18          
S8639 2023.06.09   8 2 S12E26 0012   BXO  
S8640 2023.06.09       N12W15            
S8641 2023.06.09       S11W35            
S8642 2023.06.10       S16W16            
S8645 2023.06.10       S24W36          
S8646 2023.06.10       S29E41          
S8648 2023.06.10       S42W51            
S8649 2023.06.10       S20E31            
S8651 2023.06.11   3 2 S12E14 0007   BXO  
S8652 2023.06.11       N18E41            
13333 2023.06.12
2023.06.13
10 20 13 S12E50 0070 DAO DAI area: 0210
13334 2023.06.13
2023.06.13
3 2 2 N17E68 0090 HAX HAX   was AR S8654

area: 0050

location: N17E76

S8655 2023.06.13   10 5 S21E79 0170   EAI    
S8657 2023.06.13   2 2 N20W04 0005   BXO    
S8658 2023.06.13   5 3 S14E78 0020   BXO    
S8659 2023.06.13   2 2 S13E01 0010   BXO    
Total spot count: 38 99 51  
Sunspot number: 98 229 171  (total spot count + 10 * number of spotted regions)
Weighted SN: 63 129 81  (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): 108 126 137  

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
2023.06 162.1 (1)   57.3 (2A) / 132.3 (2B) / 160.0 (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.