Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 10, 2023 at 11:00 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 9. Solar wind speed at SOHO ranged between 294 and 347 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 164.3 - 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 B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 335) and in 14 active regions using 1K resolution (SN: 234) SDO/HMI images.

Region 13320 [N10W76] decayed slowly and quietly.
Region 13321 [S15W63] was mostly quiet and stable.
Region 13323 [S09W46] decayed further and was mostly quiet. C1 flares: C1.2 @ 02:59, C1.5 @ 14:16, C1.4 @ 23:15 UT
Region 13326 [N25W13] was quiet and stable.
Region 13327 [S15E03] lost the magnetic delta configuration and decayed slowly.
Region 13329 [N22E02] was mostly quiet and stable. C1 flares: C1.4 @ 17:26, C1.1 @ 19:03 UT
Region 13330 [N17W15] decayed slowly and quietly.
Region 13331 [S23E39] produced the largest flare of the day and was otherwise mostly quiet. No major changes were observed. C1 flares: C1.9 @ 01:24, C1.3 @ 06:42 UT
Region 13332 [S08E45] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8617 [N10W13] was quiet and stable.
S8629 [N10E20] was quiet and stable.
New region S8639 [S12E79] rotated into view with small and tiny spots.
New region S8640 [N12E37] emerged with tiny spots.
New region S8641 [S11E17] was observed with tiny spots in an old plage area.

A C1.3 flare was recorded at 02:15 UT from a location behind the northwest limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.1 13:44 S13E09 13327 GOES16  
C4.5/1F 14:40 S18E09 13327 GOES16  
M2.5 17:11   13331 GOES16  
C5.8 17:47   13327 GOES16  
C2.4 23:42   13321 GOES16  

Coronal mass ejections (CMEs)

June 7-9: 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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet to active condition are possible on June 10-11 due to effects from CH1152 becoming quiet on June 12.

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 2 1 N10W75 0010 AXX AXX  
13321 2023.05.29
2023.05.30
1 5 2 S16W66 0150 HSX CHO

area: 0270

13323 2023.05.30
2023.05.31
12 24 14 S08W47 0070 ERO CRO

location: S09W46

13326 2023.06.02
2023.06.02
1 16 4 N25W16 0060 HSX CSO location: N25W13

area: 0140

S8617 2023.06.02   2 2 N10W13 0007   BXO  
13327 2023.06.03
2023.06.04
33 65 44 S17E01 0180 EAI EAC beta-gamma

area: 0290

location: S15E03

S8623 2023.06.03       N15W53            
S8625 2023.06.03       S23W34            
13328 2023.06.04
2023.06.05
      N11W59          

location: N09W55

S8629 2023.06.04   18 3 N10E20 0025   BXO  
13330 2023.06.05
2023.06.06
1 8 5 N18W17 0000 AXX AXX

location: N17W15

area: 0010

13329 2023.06.05
2023.06.06
9 31 12 N23E01 0090 DAI DSI location: N22E02

area: 0190

13331 2023.06.06
2023.06.07
3 12 2 S22E37 0180 ESO EHO area: 0410

location: S23E39

S8634 2023.06.07       S00W19            
13332 2023.06.07
2023.06.07
1 3 1 S08E45 0010 HRX CRO area: 0020
S8636 2023.06.07       N23E34          
S8637 2023.06.09       N07W21          
S8638 2023.06.09       N30W13          
S8639 2023.06.09   3 2 S12E79 0030   CRO    
S8640 2023.06.09   3 1 N12E37 0004   BXO    
S8641 2023.06.09   3 1 S11E17 0005   BXO    
Total spot count: 62 195 94  
Sunspot number: 152 335 234  (total spot count + 10 * number of spotted regions)
Weighted SN: 93 239 138  (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): 167 184 187  

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
2023.06 166.7 (1)   37.4 (2A) / 141.6 (2B) / 162.7 (2C) (134.3 projected, +3.1) (5.4)
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.