Solar Terrestrial Activity Report

Activity chart

Last major update issued on August 13, 2024 at 05:30 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 (August 4, 2024)
Solar cycle Solar cycles 23-25 (August 11, 2024) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (August 1, 2024) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (August 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (August 1, 2024) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (August 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 major to very severe storm levels on August 12 due to effects from the August 10 CME. The high latitude magnetometer at Andenes recorded minor to very severe storm 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 272.4 - increasing 39.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 168.61. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 168.61 on February 12, 2024). The Potsdam WDC planetary A index was 125 (STAR Ap - based on the mean of three hour interval ap indices: 124.9). Three hour interval K indices: 67778766 (planetary), 66866545 (Boulder), 87665655 (Andenes).

The background x-ray flux is at the class C3 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 16 active regions using 2K resolution (SN: 452) and in 15 active regions using 1K resolution (SN: 290) SDO/HMI images.

AR 13777 [S09W72] decayed and lost the magnetic delta.
AR 13780 [S08W33] decayed and was considerably less active than during the previous days.
AR 13781 [N15W28] developed slowly and quietly and has polarity intermixing.
AR 13782 [N03W01] decayed slowly and was mostly quiet.
AR 13783 [N11W39] decayed slowly and was mostly quiet.
AR 13784 [N14E22] developed further and could produce an X class flare. The dominant penumbra has become huge (larger than the main penumbra of AR 13780) and there is fairly strong magnetic shear in the south where the largest magnetic delta configuration is.
AR 13785 [S11E34] was mostly quiet and stable.
AR 13786 [S22W13] was mostly quiet and stable.
AR 13787 [N18W14] decayed slowly and quietly.
AR 13788 [S07E48] developed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S10011 [S08E17] was quiet and stable.
S10014 [S27E05] decayed slowly and quietly.
New region S10016 [S09E02] emerged with tiny spots.
New region S10017 [N23W80] emerged near the northeast limb with tiny spots.
New region S10018 [S20E29] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C9.2 00:20   13777 GOES16  
C9.2 00:23   13784 GOES16  
C6.0 00:53   13784 GOES16  
C4.8 01:57   13784 GOES16  
C4.0 02:45   13774 GOES16 simultaneous flare in AR 13777
C4.5 02:53   13784 GOES16 simultaneous flare in AR 13780
C4.1 03:55   13782 GOES16 simultaneous flare in AR 13784
C3.9 04:18   13784 GOES16  
C4.9 04:34   13784 GOES16  
C6.6 05:04   13784 GOES16  
C6.4 05:08   13788 GOES16  
C4.8 05:38 S09W61 13777 GOES16  
C4.8 05:45   13784 GOES16  
C4.5 05:55   13777 GOES16  
C4.8 06:17   13785 GOES16 simultaneous flare in AR 13784
C5.8 06:40   13777 GOES16  
C6.0 06:46   13780 GOES16  
C6.6 06:50   13784 GOES16  
C5.4 07:27   13780 GOES16  
C4.9 07:43   13780 GOES16  
C5.2 07:53   13774 GOES16  
M1.0 08:48   13777 GOES16  
C6.6 11:00   13777 GOES16  
C7.8 11:41   13784 GOES16  
C6.6 13:17   13777 GOES16  
C7.0 13:23   13784 GOES16  
C3.2 14:57   13777 GOES16  
C3.2 15:28   13784 GOES16  
C3.2 15:59   13784 GOES16  
C3.8 16:19   13784 GOES16  
C3.8 16:28   13784 GOES16  
C3.9 16:34   13784 GOES16  
C3.7 17:07   13780 GOES16  
C4.2 18:47   13780 GOES16  
C4.3 19:39   13784 GOES16  
C4.9 19:46   13784 GOES16  
C5.2 19:51   13784 GOES16  
C4.3 20:02   13784 GOES16  
C4.6 20:19   13784 GOES16  
C4.2 20:39   13784 GOES16  
C3.5 21:19   13784 GOES16  
C6.2 21:54 N14E22 13784 GOES16  
C4.6 22:14   13784 GOES16  
M1.2 22:57   13784 GOES16 simultaneous flare in AR 13781
C4.1 23:44   13784 GOES16  

Coronal mass ejections (CMEs)

August 10: A halo CME was observed after the M5 flare in AR 13780 at 02:37 UT. The CME reached Earth late on August 11.
August 11-12: 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]

No obvious coronal holes are currently in or near Earth facing positions.

Propagation

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

Forecast

The geomagnetic field is expected to be at quiet to minor storm levels on August 13. Quiet conditions are likely on August 14-15.

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
13774 2024.07.30 7     S06W88 0090 CAO    

location: S06W91

rotated out of view

SWPC spot count is questionable

13777 2024.08.01
2024.08.02
14 11 5 S10W74 0270 DKC EAO

area: 0480

location: S09W72

13780 2024.08.03
2024.08.04
40 80 43 S10W34 1100 FKI FKC beta-gamma-delta

location: S08W33

S9992 2024.08.03       N18W45            
13781 2024.08.04
2024.08.05
2 18 8 N15W28 0130 HSX CSO

area: 0180

13782 2024.08.06
2024.08.07
12 30 8 N03W01 0080 CAO CAO  
S9999 2024.08.06       N28W44          
13783 2024.08.07
2024.08.08
2 8 5 N11W37 0010 BXO CRO location: N11W39

area: 0020

13784 2024.08.07
2024.08.09
25 41 20 N15E21 0510 DKC DKC beta-delta

area: 1010

13786 2024.08.07
2024.08.11
12 31 18 S22W13 0060 CAI DAI location: S22W00
S10006 2024.08.08       S09E18            
13785 2024.08.09
2024.08.11
6 23 11 S12E34 0030 BXO DRI beta-gamma

location: S11E34

13787 2024.08.09
2024.08.11
3 11 6 N18W14 0040 DAO DRO  
S10011 2024.08.10   9 3 S08E17 0015   BXO  
13788 2024.08.10
2024.08.11
12 12 7 S07E50 0140 CAO DAI location: S07E48

area: 0250

S10013 2024.08.10       N26E52          
S10014 2024.08.11   5 1 S27W03 0010   AXX  
S10015 2024.08.11   2 1 N18E05 0004   BXO  
S10016 2024.08.12   6 3 S09E02 0015   BXO    
S10017 2024.08.12   2   N23W80 0002   AXX    
S10018 2024.08.12   3 1 S20E29 0005   BXO    
Total spot count: 135 292 140  
Sunspot number: 245 452 290  (total spot count + 10 * number of spotted regions)
Weighted SN: 195 346 194  (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): 270 249 232  

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
2022.11 123.4 120.7 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  176.4 182.2 160.0 124.6 (-0.7) 8.15
2023.08  153.7 157.6 114.8 124.3 (-0.3) 7.19
2023.09  154.4 156.0 134.2 124.0 (-0.3) 14.26
2023.10  142.8 141.9 99.4 124.8 (+0.8) 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
2024.01 164.6 159.3 126.0 131.1 (+1.7) 5.46
2024.02 172.5 168.3 123.0 (137.4 projected, +6.3) 5.31
2024.03 154.4 152.9 103.7 (144.1 projected, +6.7) 11.03
2024.04 161.3 162.6 136.5 (148.2 projected, +4.1) 9.69
2024.05 187.7 191.9 171.7 (152.9 projected, +4.7) 23.56
(SC25 peak)
2024.06 184.3 190.2 164.2 (156.9 projected, +4.0) 10.24
2024.07 196.6
(cycle peak)
203.0 196.5  (SC25 peak) (158.7 projected, +1.8) 7.13
2024.08  269.8 (1)   94.4 (2A) / 243.8 (2B) / 245.4 (2C) (159.1 projected, +0.4) (23.0)
2024.09       (161.0 projected, +1.9)  
2024.10       (162.8 projected, +1.8)  
2024.11       (160.8 projected, -2.0)  
2024.12       (156.4 projected, -4.4)  
2025.01       (150.3 projected, -6.1)  
2025.02       (143.0 projected, -7.3)  

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 August 12, 2024

Sunspot counts in July 2024 were the highest we've seen for a single month during solar cycle 25. The first part of August has seen very high sunspot counts, and there more than a remote possibility that we'll see activity in August approaching the most active months of solar cycle 23. With at least 4 consecutive months of high sunspot counts the projected peak for the smoothed ISN (365 days smoothing) has increased significantly to above 160. The month of the peak is currently likely to occur sometime between July and November 2024.

--------------------------------------------------------------------------------------

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.