Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 15, 2024 at 08:50 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 moothing 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 levels on July 14. The high latitude magnetometer at Andenes recorded quiet to unsettled 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 233.9 - increasing 54.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 163.63. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 163.63 on January 14, 2024). The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.4). Three hour interval K indices: 21121012 (planetary), ******** (Boulder), 31022002 (Andenes).

The background x-ray flux is at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 17 active regions using 2K resolution (SN: 517) and in 16 active regions using 1K resolution (SN: 326) SDO/HMI images.

AR 13738 [S08W57] was unstable and produced many flares. The magnetic delta configurations are still present and further major flares are possible.
AR 13742 [S24E07] was mostly quiet and stable.
AR 13743 [S08W02] developed slowly and was mostly quiet.
AR 13744 [N16E12] has a magnetic delta configuration in the southern spot section and could produce M flares.
AR 13745 [S19E04] was mostly quiet and stable.
AR 13748 [N15E30] has many tiny spots and was quiet.
AR 13749 [S33E55] was mostly quiet and stable.
AR 13750 [S20E54] developed slowly and quietly.
AR 13751 [S08E66] developed slowly and could produce M flares.
New region 13752 [N22E67] rotated into view on July 13 and was numbered by SWPC the next day.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S9888 [N11W08] was mostly quiet and stable.
S9895 [S07E04] was quiet and stable.
S9901 [N35E09] was quiet and stable.
New region S9903 [N24E82] rotated into view and could produce M flares. The southermost spot could be a separate region.
New region S9904 [N16E50] was observed with tiny spots in an old plage area.
New region S9905 [S35E37] emerged with a tiny spot.
New region S9906 [S24W22] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.9 00:35   13751 GOES16  
C6.1 00:52   13738 GOES16  
M1.7 01:20   13738 GOES16  
C7.8 02:03   13738 GOES16  
X1.2 02:34   13738 GOES16 simultaneous flare in AR 13751
M1.0 03:51   13751 GOES16  
M3.0 04:13   13738 GOES16  
C8.7 04:37   13738 GOES16  
C5.0 05:14   13751 GOES16  
C4.8 05:22   13743 GOES16  
C4.5 05:42   13738 GOES16  
C4.2 06:42   13738 GOES16  
C4.4 06:53   13751 GOES16  
C3.7 08:08   13751 GOES16  
C7.1 08:26   13743 GOES16 SWPC attributes this to smaller, simultaneous flare in AR 13738
C6.1 09:33   13742 GOES16 simultaneous events in ARs 13738 and 13743
C4.9 10:11   13738 GOES16  
M1.0 10:20 S13W45 13738 GOES16  
C3.8 11:37   13738 GOES16  
C7.0 12:07 S08E75 13751 GOES16  
C5.6 12:44 S14W47 13738 GOES16  
C4.1 13:11   13738 GOES16  
C5.1 13:30   13751 GOES16 incorrectly attributed to AR 13738 by SWPC
C3.9 13:45   13738 GOES16  
C3.4 13:59   13743 GOES16  
C4.4 14:39   13738 GOES16  
C4.0 14:58   13751 GOES16  
C4.2 15:04   13738 GOES16  
C4.4 15:12   13738 GOES16  
C5.0/1N 16:15   13738 GOES16  
C5.5 16:28   13738 GOES16  
C4.2 16:55   13738 GOES16  
C3.6 17:13   13744 GOES16  
C4.2 17:25   13738 GOES16  
C4.1 17:37   13751 GOES16  
C3.6 17:51   13743 GOES16  
C4.8 18:09   13738 GOES16  
C4.1 18:14   13738 GOES16  
C4.8 19:04   13738 GOES16  
C6.8/1F 19:44 S07W55 13738 GOES16  
C8.1 20:20   13738 GOES16  
M1.0 20:57   13738 GOES16  
C7.1 21:26   13751 GOES16  
C8.2/1N 21:58   13744 GOES16  
C4.5 22:40   13743 GOES16  
C4.2 23:46   13738 GOES16  

Coronal mass ejections (CMEs)

July 12-14: 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 large negative polarity coronal hole in the northern hemisphere will be rotating across the central meridian on July 14-16 but is likely too far to the north to cause a disturbance.

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

The geomagnetic field is expected to be quiet on July 15-17.

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
13736 2024.07.02
2024.07.03
1     S20W83 0010 AXX     location: S19W81

spotless

13738 2024.07.04
2024.07.05
40 73 38 S09W53 1140 FKC FKC beta-gamma-delta

location: S08W57

13741 2024.07.07
2024.07.07
      N09W37         location: N10W30
13742 2024.07.07
2024.07.09
2 28 12 S23W12 0010 AXX CSO area: 0220

location: S24E07

SWPC split off the trailing spot section into AR 13747 on 2024.07.11

13743 2024.07.08
2024.07.09
20 68 32 S08W05 0160 DAI DAI

area: 0230

location: S08W02

13745 2024.07.08
2024.07.10
5 12 8 S15E03 0020 DRO DRO area: 0060

location: S19E04

13744 2024.07.09
2024.07.09
8 33 15 N15E13 0150 DSO DAC

beta-delta

area: 0240

location: N16E12

S9884 2024.07.09       N18W45          
S9885 2024.07.09       S07W37            
S9886 2024.07.09       S24W41            
S9888 2024.07.10   35 18 N11W08 0070   DRO  
13746 2024.07.10
2024.07.11
      N23W65          

location: N21W62

13748 2024.07.10
2024.07.12
2 24 7 N15E30 0010 BXO BXO  
S9893 2024.07.10       N40W20            
13747 2024.07.11 1     S25E04 0140 HSX       AR 13747 is the trailing spot section of AR 13742
S9895 2024.07.12   11 3 S07E04 0020   BXO  
13750 2024.07.12
2024.07.13
6 23 8 S20E52 0110 CSO DAI location: S20E54

area: 0180

13749 2024.07.12
2024.07.13
3 7 3 S32E52 0050 CSO EAO area: 0100

location: S33E55

13751 2024.07.13
2024.07.13
7 20 14 S07E66 0230 EAI EAI

location: S08E66

area: 0420

13752 2024.07.13
2024.07.14
2 1 1 N22E67 0030 HAX HSX  
S9901 2024.07.13   1 1 N35E09 0003   AXX  
S9902 2024.07.13       N25W12          
S9903 2024.07.14   3 3 N24E82 0140   DAO    
S9904 2024.07.14   2   N16E50 0003   BXO    
S9905 2024.07.14   1 1 S35E37 0002   AXX    
S9906 2024.07.14   5 2 S24W22 0008   BXO    
Total spot count: 97 347 166  
Sunspot number: 217 517 326  (total spot count + 10 * number of spotted regions)
Weighted SN: 145 403 222  (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): 239 284 261  

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  176.4 182.2 160.0 124.6 (-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 (128.9 projected, -0.5) 5.46
2024.02 172.5 168.3 123.0 (129.4 projected, +0.5) 5.31
2024.03 154.4 152.9 103.7 (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
2024.07 187.5 (1)   71.2 (2A) / 157.5 (2B) / 174.2 (2C) (134.7 projected, -0.2) (5.4)
2024.08       (134.1 projected, -0.6)  
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.