Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 17, 2023 at 09:50 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 unsettled to major storm on June 16 due to effects related to CH1153. Solar wind speed at SOHO ranged between 576 and 757 km/sec. The high latitude magnetometer at Andenes recorded unsettled to severe storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 157.2 - decreasing 12.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.75. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 35 (STAR Ap - based on the mean of three hour interval ap indices: 34.6). Three hour interval K indices: 56454333 (planetary), 46544333 (Boulder), 76544345 (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: 312) and in 13 active regions using 1K resolution (SN: 210) SDO/HMI images.

Region 13331 [S23W52] was mostly unchanged and produced a few flares.
Region 13333 [S11E09] was mostly quiet and stable. The region could produce a minor M class flare.
Region 13334 [N15E36] was quiet and stable.
Region 13335 [S15E36] developed a weak magnetic delta configuration in an intermediate spot section. An M class flare is possible. C1 flares: C1.5 @ 00:13 UT
Region 13336 [S21E44] decayed slowly and quietly.
Region 13337 [N18E58] decayed slowly and quietly.
Region 13338 [N11E57] decayed slowly and produced 2 M class flares.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8639 [S13W12] was quiet and stable.
S8665 [S13W06] was quiet and stable.
S8666 [N26W46] decayed slowly and quietly.
S8668 [N17W30] was quiet and stable.
New region S8669 [N15W18] emerged with tiny spots.
New region S8670 [N07E65] emerged with a tiny spot.
New region S8671 [S19E83] rotated into view with a large, mature spot. C1 flares: C1.7 @ 14:49, C1.5 @ 21:13 UT

AR 13329 produced a C1.8 flare at 16:16 UT
AR 13327 produced a C1.9 flare at 04:14 and a C1.4 flare at 17:02 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.1 01:01   13338 GOES16 simultaneous flare in AR 13336
C2.8 02:43   13329 GOES16  
C3.5 02:54   13338 GOES16  
C2.5 03:54   13327 GOES16 simultaneous flare in AR 13338
M1.0 05:30   13338 GOES16 incorrectly attributed to AR 13327 by SWPC
C3.2 06:19   13327 GOES16  
C3.5 09:04   13329 GOES16  
M1.0 10:36   13338 GOES16  
C2.1 13:03   13335 GOES16  
C2.7 13:24 S23W42 13331 GOES16  
C2.3 13:40   13338 GOES16  
M1.0 19:59   13331 GOES16  
C2.6 20:20   13333 GOES16  
C2.1 21:41   13335 GOES16  
C2.2 21:53   13335 GOES16  

Coronal mass ejections (CMEs)

June 14-16: 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) rotated across the central meridian on June 12-15. A southern hemisphere coronal hole (CH1154) will be Earth facing on June 16-17.

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 fair.

Forecast

Quiet to active geomagnetic conditions are expected for June 17 due to effects from CH1153, quiet to unsettled is likely on June 18. A high speed stream from CH1154 could cause quiet to active conditions on June 19-20.

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
13331 2023.06.06
2023.06.07
2 5 3 S23W53 0070 HSX CAO

location: S23W52

13332 2023.06.07
2023.06.07
      S10W45        

location: S12W48

S8639 2023.06.09   6 2 S13W12 0010   BXO  
S8640 2023.06.09       N12W54            
S8642 2023.06.10       S16W55            
S8646 2023.06.10   3 1 S30E03 0008   BXO    
S8649 2023.06.10       S20W08            
S8651 2023.06.11       S12W25            
S8652 2023.06.11       N18E02            
13333 2023.06.12
2023.06.13
16 33 24 S11E10 0220 DAI EAI location: S11E09
13334 2023.06.13
2023.06.13
1 10 3 N17E36 0010 AXX BXO

location: N15E36

area: 0020

13336 2023.06.13
2023.06.14
8 28 10 S21E44 0080 CAO CAO

 

S8657 2023.06.13       N20W43            
13335 2023.06.13
2023.06.14
18 46 23 S15E37 0380 EHI ESI beta-delta

area: 0490

location: S15E36

S8660 2023.06.14       S20W35            
S8661 2023.06.14       N22E42            
13337 2023.06.14
2023.06.15
1 2   N17E59 0010 AXX AXX location: N18E58

area: 0004

13338 2023.06.14
2023.06.15
4 10 5 N11E59 0140 CSO DSO beta-gamma

area: 0220

location: N11E57

S8664 2023.06.14       S10W38            
S8665 2023.06.15   1 1 S13W08 0003   AXX  
S8666 2023.06.15   5 3 N26W46 0012   BXO  
S8667 2023.06.15       N27W04          
S8668 2023.06.15   4 1 N17W30 0010   BXO  
S8669 2023.06.16   7 3 N15W18 0015   BXO    
S8670 2023.06.16   1   N07E65 0001   AXX    
S8671 2023.06.16   1 1 S19E83 0260   HHX    
Total spot count: 50 162 80  
Sunspot number: 120 312 210  (total spot count + 10 * number of spotted regions)
Weighted SN: 80 197 115  (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): 132 172 168  

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) 10.67
2023.06 160.1 (1)   68.6 (2A) / 128.7 (2B) / 162.6 (2C) (134.3 projected, +3.1) (8.0)
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.