The geomagnetic field was at quiet to unsettled levels on July 23. A solar wind shock was observed at ACE at 19:49 UT, likely the arrival of the July 21 CME. The CME has not caused any significant disturbance yet as the Bz component of the IMF has been predominantly northwards. The high latitude magnetometer at Andenes recorded quiet levels. The above 10 MeV proton flux was at 9 pfu at the end of the day and has returned to background levels at the time of this update.
Solar flux density measured at 20h UT on 2.8 GHz was 175.5 - decreasing 5.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 164.35. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 164.35 on January 23, 2024). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.3). Three hour interval K indices: 10111131 (planetary), ******** (Boulder), 21012121 (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 25 active regions using 2K resolution (SN: 453) and in 18 active regions using 1K resolution (SN: 273) SDO/HMI images.
AR 13749 [S32W64] reemerged with a tiny spot.
AR 13751 [S08W58] decayed further losing spots
and area. An M3.6 flare was recorded at 07:42 UT on July 24.
AR 13752 [N24W44] was quiet and stable.
AR 13754 [N26W32] was quiet and stable.
AR 13755 [N03W35] was quiet and stable.
AR 13756 [S17W25] was quiet and stable.
AR 13757 [N18W20] decayed slowly and quietly.
AR 13759 [S05W83] decayed slowly and quietly.
AR 13761 [S10W42] decayed slowly and produced several C flares. C1
flares: C1.9 @ 10:28, C1.9 @ 12:14 UT
AR 13762 [S13E29] saw a large drop in flare frequency and intensity
compared to the previous day. M flares are still possible. C1 flares: C1.7 @
11:44 UT
AR 13763 [N03E59] was quiet and stable.
AR 13764 [S04E65] gained trailing spots and was quiet.
New region 13765 [S12E74] rotated into view.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9925 [S12E18] developed further and still has magnetic delta configuration
in the trailing spot section. The leading spots of AR 13762 are close to the
trailing spots of this AR. An M class flare is possible.
S9931 [N19E27] was quiet and stable.
S9941 [N24E08] was quiet and stable.
S9943 [S17E01] was quiet and stable.
New region S9947 [N18W80] emerged with tiny spots.
New region S9948 [N30E32] was observed with tiny spots in an
old plage area.
New region S9949 [S01E16] is a trans equatorial
spot group, spots were observed in an old plage area.
New region S9950 [N20E18] emerged with tiny spots.
New region S9951 [N13E33] emerged with tiny spots.
New region S9952 [S28E24] emerged with a tiny
spot.
New region S9953 [S31E54] emerged with a tiny spot.
New region S9954 [S02E18] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.7 | 00:19 | 13762 | GOES16 | ||
| C2.5 | 00:54 | 13765 | GOES16 | ||
| C2.6 | 01:20 | 13765 | GOES16 | ||
| C2.7 | 01:36 | northwest limb | GOES16 | ||
| C2.9 | 02:21 | northwest limb | GOES16 | ||
| C4.5 | 03:49 | 13762 | GOES16 | ||
| C4.5 | 03:57 | 13761 | GOES16 | ||
| C2.9 | 04:50 | 13762 | GOES16 | ||
| C3.0 | 05:29 | 13765 | GOES16 | ||
| C2.6 | 06:16 | 13762 | GOES16 | ||
| C2.7 | 06:42 | 13762 | GOES16 | ||
| C2.2 | 07:45 | GOES16 | |||
| C8.5/1N | 09:12 | 13761 | GOES16 | ||
| C2.2 | 13:22 | 13761 | GOES16 | ||
| C2.7 | 13:27 | 13761 | GOES16 | ||
| C2.1 | 13:42 | 13765 | GOES16 | ||
| M2.4 | 14:28 | S10E77 | 13765 | GOES16 | LDE, moderate type II radio sweep |
| M1.2 | 15:13 | 13761 | GOES16 | ||
| C4.7 | 16:30 | 13761 | GOES16 | ||
| C3.8 | 16:48 | S9925 | GOES16 | ||
| C3.2 | 17:22 | 13761 | GOES16 | ||
| C2.6 | 18:44 | 13765 | GOES16 | ||
| C2.1 | 21:53 | 13761 | GOES16 | ||
| C4.8 | 22:39 | S06W60 | 13751 | GOES16 | |
| C5.0 | 23:34 | 13762 | GOES16 |
July 22-23: No obviously Earth directed CMEs were observed.
July 21: AR 13757 produced an M1 flare at 16:31 UT. The associated
full halo CME likely reached Earth on July 23.
[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 to unsettled on July 24-25 with a possibility of active intervals due to the current CME disturbance. Quiet conditions are likely on July 26-27.
| 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 | ||||||||||
| 13750 | 2024.07.12 2024.07.13 |
S20W77 |
location: S20W66 |
||||||||
| 13749 | 2024.07.12 2024.07.13 |
1 | S33W66 | 0002 | AXX |
 |
location: S32W64 | ||||
| 13751 | 2024.07.13 2024.07.13 |
8 | 25 | 11 | S08W56 | 0150 | ESO | EKI |
 |
 |
beta-gamma location: S08W58 area: 0290 |
| 13752 | 2024.07.13 2024.07.14 |
2 | N22W55 | 0003 | BXO |
 |
 |
location: N24W44 |
|||
| 13754 | 2024.07.14 | 4 | 1 | N25W38 | 0007 | BXO |
 |
 |
location: N26W32 |
||
| 13760 | 2024.07.14 2024.07.18 |
N20W74 |
 |
location: N19W74 | |||||||
| S9907 | 2024.07.15 | N22W36 | |||||||||
| 13755 | 2024.07.15 2024.07.16 |
3 | 11 | 5 | N04W35 | 0015 | CRO | CRO |
 |
 |
location: N03W35 area: 0025 |
| 13756 | 2024.07.15 2024.07.16 |
1 | 2 | 1 | S17W27 | 0090 | HSX | CSO |
 |
 |
area: 0130 location: S17W25 |
| 13757 | 2024.07.15 2024.07.16 |
2 | 9 | 3 | N17W19 | 0030 | HRX | CAO |
 |
 |
location: N18W20 |
| 13759 | 2024.07.15 2024.07.17 |
1 | 2 | 1 | S04W78 | 0110 | EAO | HAX |
 |
 |
location: S05W83 SWPC classification is impossible with one spot |
| S9917 | 2024.07.16 | N19W41 | |||||||||
| 13761 | 2024.07.18 2024.07.19 |
23 | 31 | 18 | S10W42 | 0300 | DKI | EKI |
 |
 |
area: 0460 |
| S9923 | 2024.07.19 | S20W55 | |||||||||
| S9925 | 2024.07.19 | 21 | 13 | S12E18 | 0160 | DAI |
 |
 |
beta-delta | ||
| 13762 | 2024.07.19 | 25 | 38 | 20 | S12E24 | 0220 | EAI | DAC |
 |
 |
beta-delta area: 0200 location: S13E29 SWPC apparently includes AR S9925 in this AR |
| S9927 | 2024.07.19 | N10E05 | |||||||||
| S9928 | 2024.07.19 | S04W14 | |||||||||
| S9929 | 2024.07.19 | S35W51 | |||||||||
| S9930 | 2024.07.20 | N44W51 | |||||||||
| S9931 | 2024.07.20 | 4 | 1 | N19E27 | 0007 | BXO |
 |
 |
|||
| 13763 | 2024.07.21 2024.07.22 |
2 | 2 | 2 | N03E61 | 0110 | DSO | ESO |
 |
 |
location: N03E59 area: 0240 |
| S9936 | 2024.07.21 | N22E52 | |||||||||
| S9937 | 2024.07.21 | N28E32 | |||||||||
| S9938 | 2024.07.21 | S25W18 | |||||||||
| S9939 | 2024.07.21 | N09W43 | |||||||||
| 13764 | 2024.07.22 2024.07.22 |
1 | 10 | 6 | S04E62 | 0030 | HAX | EAO |
 |
 |
area: 0100 location: S04E65 |
| S9941 | 2024.07.22 | 14 | 4 | N24E08 | 0020 | BXO |
 |
 |
|||
| S9942 | 2024.07.22 | N08E01 |
 |
||||||||
| S9943 | 2024.07.22 | 3 | 1 | S17E01 | 0005 | AXX |
 |
 |
|||
| S9944 | 2024.07.22 | S03W05 |
 |
||||||||
| S9945 | 2024.07.22 | S18W09 |
 |
||||||||
| 13765 | 2024.07.23 2024.07.23 |
1 | 1 | 1 | S11E74 | 0120 | HSX | HAX |
 |
was AR S9946 area: 0210 location: S12E74 |
|
| S9947 | 2024.07.23 | 3 | 1 | N18W80 | 0015 | BXO |
 |
||||
| S9948 | 2024.07.23 | 5 | N30E32 | 0007 | BXO |
 |
|||||
| S9949 | 2024.07.23 | 7 | 3 | S01E16 | 0015 | BXO |
 |
||||
| S9950 | 2024.07.23 | 2 | N20E19 | 0003 | BXO |
 |
|||||
| S9951 | 2024.07.23 | 3 | N13E33 | 0004 | BXO |
 |
|||||
| S9952 | 2024.07.23 | 1 | 1 | S28E24 | 0002 | AXX |
 |
||||
| S9953 | 2024.07.23 | 1 | S31E54 | 0002 | AXX |
 |
|||||
| S9954 | 2024.07.23 | 1 | S02E18 | 0002 | AXX |
 |
|||||
| Total spot count: | 67 | 203 | 93 | ||||||||
| Sunspot number: | 167 | 453 | 273 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 118 | 266 | 156 | (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): | 184 | 249 | 218 | ||||||||
| 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 | 195.6 (1) | 136.5 (2A) / 184.0 (2B) / 209.9 (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.
