Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 6, 2024 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 (July 3, 2024)
Solar cycle Solar cycles 23-25 (July 1, 2024) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (July 1, 2024) 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 (July 1, 2024) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (July 1, 2024) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (June 17, 2024) 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
Calculating the Strength of Solar Cycle 25 Using 365-day Smoothing

Recent activity

The geomagnetic field was at quiet to unsettled levels on July 5. The high latitude magnetometer at Andenes recorded quiet to active levels. The above 10 MeV proton flux was at background levels at the end of the day.

Solar flux density measured at 20h UT on 2.8 GHz was 165.6 - decreasing 24.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 163.27. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 163.27 on January 5, 2024). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.4). Three hour interval K indices: 23123211 (planetary), ******** (Boulder), 34123331 (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 16 active regions using 2K resolution (SN: 310) and in 13 active regions using 1K resolution (SN: 189) SDO/HMI images.

Region 13727 [S18W72] decayed slowly and quietly.
Region 13729 [S05W59] gained a magnetic delta configuration  within the leader spot and produced several C flare. A minor M class flare is possible.
Region 13733 [N04W53] developed slowly  and could produce M flares.
Region 13734 [N09W15] decayed slowly and quietly.
Region 13735 [N16W03] decayed slowly and quietly.
Region 13736 [S19E38] was mostly quiet and stable.
New region 13738 [S08E70] rotated into view on July 4 and was numbered the next day by SWPC. The spot group developed slowly and was mostly quiet. M class flares are possible, the region has a small magnetic delta configuration.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9830 [S09W75] was quiet and stable.
S9858 [S23W14] reemerged with tiny spots.
S9862 [N03W01] developed slowly and quietly.
S9863 [S03W48] decayed quickly and was quiet.
S9864 [S01W63] decayed slowly and quietly.
S9866 [N22W05] was quiet and stable.
S9867 [S19E12] developed slowly and quietly.
New region S9868 [N32W02] was observed with tiny spots in an old plage area.
New region S9869 [N27E12] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 00:09   13737 GOES16  
C2.2 00:49   13737 GOES16  
C2.4 02:54   13734 GOES16  
C6.1 05:18   13729 GOES16  
C2.3 06:19   13738 GOES16 incorrectly attributed to AR 13721 by SWPC
C2.3 12:08   S9830 GOES16  
C2.9 12:42   13736 GOES16  
C4.1 15:13   13729 GOES16 SWPC attributes this to a simultaneous flare in AR 13737
C3.2 16:20   13729 GOES16  
C3.6 16:38   13729 GOES16  
C3.1 17:09   13736 GOES16  
C9.4 19:03 behind southwest limb   GOES16  
C3.0 19:46   13737 GOES16  
C8.6 20:10 S03W60 13729 GOES16  
C5.5 21:16   13737 GOES16  
C5.0 22:54   13737 GOES16  
C7.7 23:56   13737 GOES16  

Coronal mass ejections (CMEs)

July 3-5: No obviously Earth directed CMEs 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 negative polarity southern hemisphere coronal hole (CH1230) could rotate into an Earth facing position on July 6-7.

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 poor.

Forecast

The geomagnetic field is expected to be quiet on July 6-9. Quiet to active conditions are possible on July 10 due to effects from CH1230.

Coronal holes (1) Coronal mass ejections (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
13723 2024.06.22
2024.06.23
      S18W89          

location: S20W79

13728 2024.06.23
2024.06.25
      S26W80          

location: S25W66

13727 2024.06.24
2024.06.25
2 1 1 S18W69 0080 HAX HAX location: S18W72
S9830 2024.06.24   3 2 S09W75 0010   BXO  
13729 2024.06.25
2024.06.26
10 11 7 S04W52 0100 EAO DAC

beta-delta

location: S05W59

13731 2024.06.26
2024.06.28
      S16W48        

location: S17W40

13732 2024.06.28       S20W81            
13733 2024.06.28
2024.06.29
8 23 10 N03W55 0460 DKC DKI

location: N04W53

13734 2024.06.28
2024.06.29
2 22 5 N09W18 0020 HRX CRO location: N09W15
13735 2024.06.29
2024.06.29
1 5 2 N16W04 0030 HAX CRO

location: N16W03

S9847 2024.06.29       S13W33            
S9849 2024.06.29       S16W48            
S9851 2024.06.30       S40W35            
S9854 2024.07.01       N23W33            
13737 2024.07.01
2024.07.04
2     S14W88   DSO     rotated out of view
S9856 2024.07.01       S28W44            
13736 2024.07.02
2024.07.03
3 13 6 S19E42 0120 DSO ESO location: S19E38

area: 0200

S9858 2024.07.02   2   S23W14 0005   AXX    
S9859 2024.07.03       S27E41            
S9860 2024.07.03       S04W36            
S9861 2024.07.04       N10W22          
S9862 2024.07.04   10 5 N03W01 0025   BXO  
S9863 2024.07.04   6 2 S03W48 0015   BXO split off from AR 13729
S9864 2024.07.04   2 1 S01W63 0008   HRX split off from AR 13729
13738 2024.07.04
2024.07.05
3 27 12 S08E70 0080 DAO EAC beta-delta

area: 0300

S9866 2024.07.04   8 2 N22W05 0013   BXO    
S9867 2024.07.04   10 4 S19E12 0030   DRO  
S9868 2024.07.05   5   N32W02 0008   BXO    
S9869 2024.07.05   2   N27E12 0003   BXO    
Total spot count: 31 150 59  
Sunspot number: 111 310 189  (total spot count + 10 * number of spotted regions)
Weighted SN: 74 192 101  (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): 122 171 151  

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
2022.10 133.5 132.7 95.5 98.9 (+2.4) 11.16
2022.11 123.4 120.7 80.5 101.2 (+2.3) 9.33
2022.12 147.9 143.4 112.8 106.7 (+5.5) 10.99
2023.01 182.4 176.6 144.4 113.3 (+6.6) 8.73
2023.02 167.2 163.2 111.3 117.8 (+3.5) 14.48
2023.03 157.2 155.6 123.3 121.1 (+3.3) 14.42
2023.04 145.4 146.4 97.6 122.9 (+1.8) 13.40
2023.05 155.6 159.2 137.4 124.2 (+1.3) 10.67
2023.06 161.7 166.8 160.5 125.3 (+1.1) 8.95
2023.07  176.4 182.2 160.0 124.4 (-0.9) 8.15
2023.08  153.7 157.6 114.8 124.1 (-0.3) 7.19
2023.09  154.4 156.0 134.2 123.9 (-0.2) 14.26
2023.10  142.8 141.9 99.4 124.8 (+0.9) 8.16
2023.11 153.5 150.2 105.4 127.8 (+3.0) 12.20
2023.12 151.1 146.4 114.2 129.4 (+1.6) 9.60
2024.01 164.6 159.3 123.0 (128.9 projected, -0.5) 5.46
2024.02 172.5 168.3 124.7 (129.4 projected, +0.5) 5.31
2024.03 154.4 152.9 104.9 (130.3 projected, +0.9) 11.03
2024.04 161.3 162.6 136.5 (131.0 projected, +0.7) 9.69
2024.05 187.7
(cycle peak)
191.9 171.7 (SC25 peak) (133.2 projected, +2.2) 23.56
(SC25 peak)
2024.06 184.3 190.2 164.2 (134.9 projected, +1.7) 10.24
2024.07 168.1 (1)   25.4 (2A) / 158.0 (2B) / 158.7 (2C) (134.8 projected, -0.1) (5.8)
2024.08       (134.3 projected, -0.5)  
2024.09       (134.4 projected, +0.1)  
2024.10       (134.3 projected, -0.1)  
2024.11       (132.3 projected, -2.0)  
2024.12       (128.0 projected, -4.3)  
2025.01       (124.0 projected, -4.0)  

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

Update on the progress of solar cycle 25 as of July 5, 2024

Sunspot counts in June 2024 were almost at the level of May 2024 and the second highest month during solar cycle 25. Looking at the projected activity for the remainder of this year, solar max now looks likely to occur between May and October 2024. A big decrease in sunspot formation in July 2024 and over the next months could change the projected maximum to earlier in 2024 or even to December 2023.

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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.