Solar Terrestrial Activity Report

Activity chart

Last major update issued on August 12, 2024 at 05:45 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 quiet to minor storm levels on August 11 under the influence of CME effects. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at background levels at the end of the day. Another CME arrived late on August 11 and is causing severe geomagnetic storming early on August 12.

Solar flux density measured at 20h UT on 2.8 GHz was 281.5 - increasing 47.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 168.27. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 168.27 on February 11, 2024). The Potsdam WDC planetary A index was 29 (STAR Ap - based on the mean of three hour interval ap indices: 29.4). Three hour interval K indices: 22345445 (planetary), 33445434 (Boulder), 12344435 (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: 442) and in 15 active regions using 1K resolution (SN: 305) SDO/HMI images.

AR 13774 [S06W78] decayed slowly and was mostly quiet.
AR 13777 [S10W58] developed in the trailing spot section as a magnetic delta configuration formed. M flares are likely.
AR 13780 [S08W22] lost spots and area and is slowly decaying. There are still multiple magnetic delta configurations in the largest penumbra. A major flare is possible.
AR 13781 [N15W19] decayed slowly and quietly.
AR 13782 [N03E12] decayed slowly and was mostly quiet.
AR 13783 [N10W25] decayed slowly and quietly.
AR 13784 [N15E35] developed as the southernmost spots once again joined the largest penumbra. M flares are likely.
New AR 13785 [S11E48] rotated into view on August 9 and was numbered by SPWC 2 days later.
New AR 13786 [S22W00] was first observed with spots on August 7, SWPC numbered the spot group 4 days later as new flux emerged.
New AR 13787 [N18W01] emerged on August 9 and received its NOAA number 2 days later  as slow development continued.
New AR 13788 [S07E62] rotated into view on August 10 and developed slowly on August 11 when the spot group was numbered by SWPC.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9999 [N28W31] reemerged with tiny spots.
S10011 [S06E24] was quiet and stable.
S10013 [N26E65] was quiet and stable.
New region S10014 [S30E10] emerged with tiny spots.
New region S10015 [N18E15] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C6.2 00:15   13774 GOES16  
M1.0 00:31   13780 GOES16  
C8.2 01:06   13777 GOES16  
M1.0 01:11   13780 GOES16  
C4.8 02:10   13784 GOES16  
C6.8 02:55 S12W11 13780 GOES16 simultaneous flare in AR 13774
C4.4 03:21   13788 GOES16  
C5.2 03:44   13780 GOES16  
C6.7 04:05   13777 GOES16  
C8.1 04:17   13777 GOES16  
C4.9 05:17   13774 GOES16  
M1.6/1N 05:28 S14W16 13780 GOES16  
C4.4 06:15   13777 GOES16  
C3.6 06:41   13786 GOES16  
C4.2 06:59 S08W52 13777 GOES16  
C3.6 07:18   13774 GOES16  
C3.8 07:39   13780 GOES16  
C3.3 08:03   13777 GOES16  
C4.4 08:41 S13W10 13780 GOES16  
C4.7 08:53   13780 GOES16  
C4.0 09:41   13777 GOES16  
C3.5 11:09   13780 GOES16  
C3.5 11:28   13780 GOES16  
C3.6 11:57   13774 GOES16  
C4.2 12:30   13777 GOES16  
C4.8 13:06   13777 GOES16  
C6.0 13:21   13777 GOES16  
C3.8 14:57   13777 GOES16  
C5.1 16:00   13784 GOES16  
C3.9 16:34   13777 GOES16  
C5.0 16:52 S09W54 13777 GOES16  
C4.9 17:10   13780 GOES16  
C5.0 17:59   13777 GOES16  
C5.3 18:31 S03W75 13774 GOES16  
M1.6/1F 20:16 S09W58 13777 GOES16  
C3.4 22:14   13782 GOES16  
C4.7 22:35   13777 GOES16  
M1.0 23:54   13780 GOES16  
M1.2 23:58   13777 GOES16  

Coronal mass ejections (CMEs)

August 9: A partial halo CME was observed an M4.5 flare in AR 13777 at 21:23 UT.
August 10: A halo CME was observed after the M5 flare in AR 13780 at 02:37 UT. The CME likely reached Earth late on August 11.
August 11: 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 poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be at unsettled to severe storm storm levels on August 12 due to CME effects and quiet to minor storm on August 13. Quiet conditions are possible on August 14.

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
13775 2024.07.30
2024.07.31
      N18W86        

 

location: N17W71

13774 2024.07.30 8 2 2 S06W76 0140 CAO CAO beta-gamma

area: 0160

location: S06W78

13777 2024.08.01
2024.08.02
15 22 16 S10W60 0300 EKC FAC beta-delta

area: 0540

location: S10W58

S9986 2024.08.03       S28W49            
13780 2024.08.03
2024.08.04
20 94 50 S11W20 1100 FKI FKC beta-gamma-delta

location: S08W22

13779 2024.08.03
2024.08.04
      S13W77            
S9992 2024.08.03       N18W32            
13781 2024.08.04
2024.08.05
4 9 2 N14W13 0150 CSO CSO

location: N15W15

area: 0160

S9995 2024.08.05       N07W57            
13782 2024.08.06
2024.08.07
10 24 14 N02E16 0100 CAO ESI beta-gamma

location: N03E12

S9999 2024.08.06   2 1 N28W31 0005   BXO    
13783 2024.08.07
2024.08.08
3 11 5 N10W23 0020 CRO DRO location: N10W25
13784 2024.08.07
2024.08.09
5 26 19 N15E35 0460 DKI DKC beta-delta

area: 0820

13786 2024.08.07
2024.08.11
4 27 19 S23E01 0035   CRO location: S22W00
S10006 2024.08.08       S09E18            
13785 2024.08.09
2024.08.11
5 14 6 S11E49 0030 CRO DRI beta-gamma

location: S11E48

13787 2024.08.09
2024.08.11
3 13 8 N16W00 0030 CAO DRO location: N18W01

area: 0090

S10009 2024.08.09       S19W46            
S10010 2024.08.09       S19W58            
S10011 2024.08.10   2   S06E24 0003   BXO  
13788 2024.08.10
2024.08.11
7 13 8 S06E64 0140 CAO DRI location: S07E62

area: 0050

S10013 2024.08.10   5 2 N26E65 0010   BXO  
S10014 2024.08.11   6 2 S30E10 0010   BXO    
S10015 2024.08.11   2 1 N18E15 0004   AXX    
Total spot count: 84 282 155  
Sunspot number: 194 442 305  (total spot count + 10 * number of spotted regions)
Weighted SN: 152 337 210  (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): 213 243 244  

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  269.6 (1)   80.2 (2A) / 243.6 (2B) / 245.5 (2C) (159.1 projected, +0.4) (13.7)
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.