The geomagnetic field was at quiet to unsettled levels on July 22. 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, however, an above 10 MeV event started early on July 23. This event was likely caused by a large backsided eruption as a fast, symmetrical full halo CME was observed at the same time. The current peak of the above 10 MeV proton flux is 24 pfu at 05:50 UT on July 23.
Solar flux density measured at 20h UT on 2.8 GHz was 185.0 - decreasing 8.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 164.32. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 164.32 on January 22, 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: 21232122 (planetary), ******** (Boulder), 44144443 (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 19 active regions using 2K resolution (SN: 394) and in 16 active regions using 1K resolution (SN: 269) SDO/HMI images.
AR 13751 [S08W43] decayed
fairly quickly and produced far fewer flares than over the previous days.
AR 13752 [N24W33] decayed slowly and quietly.
AR 13754 [N25W19] decayed slowly and quietly.
AR 13755 [N03W20] was quiet and stable.
AR 13756 [S18W12] decayed slowly and quietly.
AR 13757 [N17W07] decayed slowly and quietly.
AR 13759 [S05W69] decayed slowly and quietly.
AR 13760 [N19W61] decayed slowly and quietly.
AR 13761 [S10W28] decayed in the trailing spot
section and was mostly quiet.
AR 13762 [S13E42] was unstable and produced many C and M flares due
to a magnetic delta configuration.
New AR 13763 [N03E73] rotated into view on July 21 and was numbered
by SWPC the next day. The region has mature, symmetrical spots.
New AR 13764 [S03E78] rotated into view.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9925 [S12E33] developed further. A magnetic delta configuration
formed in the trailing spot section which borders on the leading polarity
area of AR 13762. An M class flare is possible.
S9931 [N20E40] decayed slowly and quietly.
New region S9941 [N27E22] was observed with tiny spots in an old
plage area.
New region S9942 [N08E14] emerged with a tiny spot.
New region S9943 [S17E14] emerged with tiny spots.
New region S9944 [S03E08] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C5.4 | 00:09 | 13744 | GOES16 | ||
| C5.4 | 00:14 | 13751 | GOES16 | ||
| C4.1 | 00:37 | 13762 | GOES16 | ||
| C3.8 | 00:54 | 13762 | GOES16 | ||
| C6.6 | 01:21 | 13762 | GOES16 | ||
| C2.8 | 01:46 | 13762 | GOES16 | ||
| C8.3 | 02:06 | 13744 | GOES16 | simultaneous flare in AR 13762 | |
| C5.0 | 02:52 | 13762 | GOES16 | ||
| M1.4 | 03:33 | S14E56 | 13762 | GOES16 | |
| C3.3 | 03:51 | 13762 | GOES16 | ||
| M3.9 | 04:04 | S15E56 | 13762 | GOES16 | |
| C8.4 | 04:27 | 13762 | GOES16 | ||
| M1.9/1F | 04:34 | S12E54 | 13762 | GOES16 | simultaneous flare in AR 13744 |
| C5.3 | 05:18 | 13762 | GOES16 | ||
| C3.1 | 05:30 | 13762 | GOES16 | ||
| C3.0 | 05:53 | 13762 | GOES16 | ||
| C3.1 | 05:57 | 13762 | GOES16 | ||
| C6.2 | 06:56 | 13751 | GOES16 | ||
| C5.7 | 07:09 | 13751 | GOES16 | ||
| C3.9 | 07:16 | GOES16 | |||
| C2.7 | 07:45 | GOES16 | |||
| C2.6 | 08:29 | 13744 | GOES16 | ||
| C4.6 | 09:11 | S16W21 | 13761 | GOES16 | simultaneous flare in AR 13744 |
| C5.0 | 09:25 | S13E45 | 13762 | GOES16 | |
| M1.4 | 09:35 | northwest limb | 13744 | GOES16 | moderate type II radio sweep |
| C7.8 | 09:53 | 13744 | GOES16 | ||
| C2.9 | 10:57 | 13762 | GOES16 | ||
| C5.9 | 12:24 | S13E51 | 13762 | GOES16 | |
| M1.5 | 13:00 | 13744 | GOES16 | ||
| C9.0 | 15:26 | S16E50 | 13762 | GOES16 | |
| C7.0 | 15:32 | 13762 | GOES16 | ||
| C7.8 | 15:47 | 13744 | GOES16 | incorrectly attributed to AR 13762 by SWPC | |
| C2.4 | 16:44 | 13757 | GOES16 | ||
| C4.5 | 17:27 | 13744 | GOES16 | ||
| C2.3 | 18:18 | 13744 | GOES16 | ||
| C3.3 | 18:48 | 13762 | GOES16 | ||
| C4.3 | 18:54 | 13762 | GOES16 | ||
| C2.9 | 19:51 | 13751 | GOES16 | ||
| C2.9 | 20:02 | 13751 | GOES16 | ||
| C2.9 | 20:29 | 13744 | GOES16 | ||
| C2.8 | 21:30 | 13751 | GOES16 | ||
| C2.7 | 21:38 | 13751 | GOES16 | ||
| C2.7 | 21:54 | 13751 | GOES16 | ||
| C3.2 | 22:10 | S11E38 | S9925 | GOES16 | |
| C2.5 | 23:17 | 13751 | GOES16 |
July 20, 22: No obviously Earth directed CMEs were observed.
July 21: AR 13757 produced an M1 flare at 16:31 UT. A filament
eruption was observed at that time in the vicinity of the region. At 17:00
UT a CME became visible over the north pole and the northeast limb, soon
after an asymmetrical full halo CME was visible in LASCO imagery. The CME
could reach Earth on July 24.
[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 locations.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair to good. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on July 22-23. Quiet to minor storm conditions are possible on July 24-25 due to effects from the July 21 CME.
| 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.
(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 | ||||||||||
| 13748 | 2024.07.10 2024.07.12 |
N15W82 |
location: N17W77 |
||||||||
| 13750 | 2024.07.12 2024.07.13 |
S20W63 |
location: S20W53 |
||||||||
| 13749 | 2024.07.12 2024.07.13 |
S33W52 |
 |
location: S32W49 | |||||||
| 13751 | 2024.07.13 2024.07.13 |
21 | 37 | 26 | S08W42 | 0180 | EAC | EKI |
 |
 |
beta-gamma-delta location: S08W43 area: 0320 |
| 13752 | 2024.07.13 2024.07.14 |
3 | N22W41 | 0005 | AXX |
 |
 |
location: N24W33 |
|||
| 13754 | 2024.07.14 | 4 | 1 | N25W24 | 0006 | BXO |
 |
 |
location: N25W19 |
||
| 13760 | 2024.07.14 2024.07.18 |
2 | 4 | N20W60 | 0010 | AXX | AXX |
 |
 |
location: N19W61 area: 0004 |
|
| S9907 | 2024.07.15 | N22W23 | |||||||||
| 13755 | 2024.07.15 2024.07.16 |
4 | 10 | 4 | N04W22 | 0020 | CRO | CRO |
 |
 |
location: N03W20 area: 0035 |
| 13756 | 2024.07.15 2024.07.16 |
1 | 5 | 1 | S17W14 | 0100 | HSX | CSO |
 |
 |
area: 0140 location: S18W12 |
| 13757 | 2024.07.15 2024.07.16 |
5 | 11 | 3 | N18W06 | 0040 | CAO | CSO |
 |
 |
location: N17W07 |
| 13759 | 2024.07.15 2024.07.17 |
8 | 10 | 6 | S06W64 | 0120 | CSO | CAO |
 |
 |
location: S05W69 area: 0220 |
| S9917 | 2024.07.16 | N19W28 | |||||||||
| S9918 | 2024.07.16 | N06W52 | |||||||||
| S9920 | 2024.07.17 | N14W53 | |||||||||
| 13761 | 2024.07.18 2024.07.19 |
16 | 42 | 26 | S10W29 | 0330 | DKI | DKI |
 |
 |
beta-gamma area: 0620 location: S10W28 |
| S9923 | 2024.07.19 | S20W42 | |||||||||
| S9924 | 2024.07.19 | S24W51 | |||||||||
| S9925 | 2024.07.19 | 23 | 15 | S12E33 | 0090 | DRI |
 |
 |
beta-gamma-delta | ||
| 13762 | 2024.07.19 | 14 | 25 | 16 | S13E37 | 0170 | EAI | DAC |
 |
 |
beta-delta area: 0230 location: S13E42 |
| S9927 | 2024.07.19 | N10E18 | |||||||||
| S9928 | 2024.07.19 | S04W01 | |||||||||
| S9929 | 2024.07.19 | S35W38 | |||||||||
| S9930 | 2024.07.20 | N44W38 | |||||||||
| S9931 | 2024.07.20 | 1 | 1 | N20E40 | 0007 | HRX |
 |
 |
|||
| 13763 | 2024.07.21 2024.07.22 |
1 | 2 | 2 | N03E70 | 0080 | HSX | ESO |
 |
 |
location: N03E73 area: 0240 |
| S9936 | 2024.07.21 | N22E65 |
 |
||||||||
| S9937 | 2024.07.21 | N28E45 |
 |
||||||||
| S9938 | 2024.07.21 | S25W05 |
 |
||||||||
| S9939 | 2024.07.21 | N09W30 |
 |
||||||||
| 13764 | 2024.07.22 2024.07.22 |
1 | 1 | 1 | S03E76 | 0030 | HSX | HSX |
 |
was AR S9940 area: 0090 location: S03E78 |
|
| S9941 | 2024.07.22 | 8 | 4 | N27E22 | 0020 | AXX |
 |
||||
| S9942 | 2024.07.22 | 2 | 1 | N08E14 | 0005 | AXX |
 |
||||
| S9943 | 2024.07.22 | 2 | 1 | S17E14 | 0010 | CRO |
 |
||||
| S9944 | 2024.07.22 | 1 | S03E08 | 0003 | AXX |
 |
|||||
| S9945 | 2024.07.22 | 3 | 1 | S18E04 | 0005 | BXO |
 |
||||
| Total spot count: | 73 | 204 | 109 | ||||||||
| Sunspot number: | 173 | 394 | 269 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 121 | 266 | 171 | (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): | 190 | 217 | 215 | ||||||||
| 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 | 196.6 (1) | 131.1 (2A) / 184.8 (2B) / 207.2 (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
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.
--------------------------------------------------------------------------------------
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.
