Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 9, 2023 at 06:55 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 8. Solar wind speed at SOHO ranged between 321 and 389 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 168.5 - increasing 19.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.16. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.5). Three hour interval K indices: 21112110 (planetary), 22222212 (Boulder), 22012231 (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 12 active regions using 2K resolution (SN: 315) and in 10 active regions using 1K resolution (SN: 207) SDO/HMI images.

Region 13320 [N10W62] was quiet and stable
Region 13321 [S15W50] was quiet and stable.
Region 13323 [S08W32] decayed slowly and quietly losing mature penumbra. C1 flares: C1.5 @ 03:26 UT
Region 13326 [N25W01] was quiet and stable.
Region 13327 [S14E16] decayed slowly and was less active than on previous days with magnetic delta configurations waning. C1 flares: C1.6 @ 02:16, C1.3 @ 12:43, C1.8 @ 16:56, C1.7 @ 19:57, C1.5 @ 20:12 UT
Region 13329 [N22E16] was mostly quiet and stable. C1 flares: C1.4 @ 17:26, C1.1 @ 19:03 UT
Region 13330 [N17W03] decayed slowly and quietly.
Region 13331 [S22E52] was mostly quiet and stable.
New region 13332 [S08E59] rotated into view on June 7 and was numbered the next day by SWPC.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8617 [N09E00] was quiet and stable.
S8629 [N11E30] decayed slowly and quietly.
S8636 [N23E47] was quiet and stable.

AR 13324 produced several flares while transiting the northwest limb. C1 flares: C1.6 @ 06:09, C1.4 @ 07:07, C1.6 @ 07:15, C1.5 @ 16:25 UT
A C1.4 flare at 19:30 UT had its origin behind the southeast limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.2 02:58 S15E58 13327 GOES16  
C7.3 04:59 S17E31 13327 GOES16  
C2.0 07:58   13324 GOES16  
C4.8 10:24   13324 GOES16  
C2.1 00:07 (flare began at 23:57)   13327 GOES16  

Coronal mass ejections (CMEs)

June 6-8: 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 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 3 1 N10W62 0010 HRX HRX area: 0015
13321 2023.05.29
2023.05.30
2 8 3 S15W53 0170 CSO CHO

area: 0270

S8606 2023.05.29       N11W55          
S8610 2023.05.30       N29W48          
13323 2023.05.30
2023.05.31
19 48 24 S08W35 0150 EAI ERI

beta-gamma

location: S08W32

area: 0100

13325 2023.06.01
2023.06.02
      N12W84           location: N09W85
13326 2023.06.02
2023.06.02
1 10 2 N25W03 0060 HSX CSO location: N25W01

area: 0140

S8617 2023.06.02   2   N09E00 0003   BXO  
13327 2023.06.03
2023.06.04
26 64 45 S16E15 0270 EKC EAC beta-gamma-delta

area: 0310

location: S14E16

S8623 2023.06.03       N15W40            
S8625 2023.06.03       S23W21          
13328 2023.06.04
2023.06.05
      N11W45        

location: N09W42

S8629 2023.06.04   10 1 N11E36 0012   BXO  
13330 2023.06.05
2023.06.06
1 14 9 N18W04 0010 AXX CRO

location: N17W03

area: 0030

13329 2023.06.05
2023.06.06
5 21 15 N23E14 0120 DAO DAI location: N22E16

area: 0270

13331 2023.06.06
2023.06.07
3 6 4 S22E48 0170 DSO EHO area: 0380

location: S22E52

S8634 2023.06.07       S00W06          
13332 2023.06.07
2023.06.07
1 5 3 S08E59 0020 HSX CRO  
S8636 2023.06.07   4   N23E47 0005   BXO  
Total spot count: 59 195 107  
Sunspot number: 149 315 207  (total spot count + 10 * number of spotted regions)
Weighted SN: 102 242 154  (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): 164 173 166  

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
2023.06 167.0 (1)   37.4 (2A) / 140.3 (2B) / 162.3 (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.