The geomagnetic field was at quiet levels on July 12. 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.
Solar flux density measured at 20h UT on 2.8 GHz was 209.7 - increasing 39.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 163.30. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 163.32 on January 7, 2024). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 21111112 (planetary), ******** (Boulder), 42212223 (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: 484) and in 13 active regions using 1K resolution (SN: 280) SDO/HMI images.
AR 13736 [S20W54] decayed
slowly and quietly.
AR 13738 [S09W28] was less active compared to the
previous days. Some decay was observed in the northern parts of the trailing
spot section and in the southern parts of the leading spots, while
development occurred in the southern section of the trailing spots section
and in the northern part of the leading spot section. The spot group has multiple small magnetic delta
configurations and could produce a major flare.
AR 13741 [N08W09] decayed slowly and quietly.
AR 13742 [S25E32] redeveloped rudimentary
penumbra on the leader spots and was mostly quiet.
AR 13743 [S09E26] gained spots and has minor polarity intermixing. An
M flare is possible.
AR 13744 [N15E40] gained spots and was mostly quiet.
AR 13745 [S17E31] was mostly quiet and stable.
New AR 13748 [N15E57] rotated into view on July 10 and was numbered 2
days later by SWPC.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9884 [N18W19] decayed slowly and quietly.
S9885 [S07W11] decayed slowly and quietly.
S9886 [S24W15] decayed slowly and quietly.
S9888 [N13E17] developed slowly and quietly.
S9892 [N07E24] decayed slowly and quietly.
New region S9895 [S11E36] emerged with tiny
spots.
New region S9896 [N18W46] emerged with a tiny spot.
New region S9897 [S20E80] rotated into view with small spots.
New region S9898 [S32E81] rotated into view with a few spots.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.1 | 00:42 | 13743 | GOES16 | ||
| C2.5 | 01:01 | 13738 | GOES16 | ||
| C2.5 | 01:23 | S10W21 | 13738 | GOES16 | |
| C3.0 | 08:28 | 13740 | GOES16 | ||
| C2.4 | 09:29 | northwest limb | GOES16 | ||
| C3.2 | 11:50 | 13738 | GOES16 | ||
| C4.6 | 12:13 | 13740 | GOES16 | ||
| C6.5 | 13:28 | S08E30 | 13743 | GOES16 | simultaneous flare in AR 13738 |
| C2.1 | 16:25 | 13740 | GOES16 | ||
| C2.3 | 17:07 | 13738 | GOES16 | ||
| C3.0 | 17:18 | northwest limb | GOES16 | ||
| C3.6 | 17:40 | S11W15 | 13738 | GOES16 | |
| C2.6 | 17:49 | 13740 | GOES16 | ||
| C2.8 | 18:12 | 13738 | GOES16 | ||
| C2.5 | 19:15 | 13738 | GOES16 | ||
| C2.1 | 20:56 | 13738 | GOES16 | ||
| C2.1 | 21:49 | 13738 | GOES16 | ||
| C3.6 | 22:36 | 13740 | GOES16 | SWPC incorrectly attributed this to smaller, simultaneous flare in AR 13745 | |
| C3.0 | 22:49 | southeast limb | GOES16 | ||
| C3.0 | 23:05 | 13738 | GOES16 | ||
| C3.8 | 23:13 | 13740 | GOES16 |
July 10-12: No obviously Earth directed CMEs observed.
[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 well defined positive polarity northern hemisphere coronal hole (CH1231) rotated across the central meridian on July 9-11.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to active on July 12-13 due to effects from CH1231 and quiet to unsettled on July 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.
(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 | 3 | 2 | S21W54 | 0020 | HAX | HRX |
 |
 |
location: S20W54 |
| S9859 | 2024.07.03 | S27W50 | |||||||||
| 13738 | 2024.07.04 2024.07.05 |
50 | 101 | 60 | S09W26 | 1100 | FKI | FKC |
 |
 |
beta-gamma-delta location: S09W28 |
| 13740 | 2024.07.04 2024.07.06 |
S18W89 |
 |
location: S17W83 |
|||||||
| S9872 | 2024.07.06 | S07W41 | |||||||||
| 13741 | 2024.07.07 2024.07.07 |
6 | N09W09 | 0008 | BXO |
 |
 |
location: N08W09 | |||
| 13742 | 2024.07.07 2024.07.09 |
4 | 31 | 16 | S23E16 | 0010 | BXO | FSO |
 |
 |
area: 0250 location: S25E32 SWPC split off the trailing spot section into AR 13747 on
2024.07.11 |
| S9875 | 2024.07.07 | S13W40 |
 |
||||||||
| S9877 | 2024.07.07 | S24W57 | |||||||||
| 13743 | 2024.07.08 2024.07.09 |
12 | 58 | 29 | S09E24 | 0200 | DSI | DAI |
 |
 |
beta-gamma area: 0300 location: S09E26 |
| S9880 | 2024.07.08 | N09W52 | |||||||||
| 13745 | 2024.07.08 2024.07.10 |
2 | 12 | 7 | S17E31 | 0020 | BXO | DRO |
 |
 |
area: 0030 |
| S9882 | 2024.07.08 | S11W53 | |||||||||
| 13744 | 2024.07.09 2024.07.09 |
7 | 27 | 11 | N16E43 | 0180 | DSO | DSI |
 |
 |
beta-gamma area: 0220 location: N15E40 |
| S9884 | 2024.07.09 | 4 | 2 | N18W19 | 0007 | AXX |
 |
 |
|||
| S9885 | 2024.07.09 | 7 | S07W11 | 0010 | BXO |
 |
 |
||||
| S9886 | 2024.07.09 | 2 | S24W15 | 0004 | AXX |
 |
 |
||||
| S9888 | 2024.07.10 | 19 | 7 | N13E17 | 0040 | BXO |
 |
 |
|||
| 13746 | 2024.07.10 2024.07.11 |
N23W37 |
 |
location: N21W36 |
|||||||
| S9890 | 2024.07.10 | S46W20 | |||||||||
| 13748 | 2024.07.10 2024.07.12 |
4 | 16 | 5 | N15E57 | 0030 | BXO | DRO |
 |
 |
|
| S9892 | 2024.07.10 | 12 | N07E24 | 0015 | BXO |
 |
 |
||||
| S9893 | 2024.07.10 | N40E06 | |||||||||
| 13747 | 2024.07.11 | 2 | S25E32 | 0180 | HSX | AR 13747 is the trailing spot section of AR 13742 | |||||
| S9895 | 2024.07.12 | 7 | 4 | S11E36 | 0020 | DRO |
 |
||||
| S9896 | 2024.07.12 | 1 | 1 | N18W46 | 0003 | AXX |
 |
||||
| S9897 | 2024.07.12 | 5 | 4 | S20E80 | 0080 | DRI |
 |
||||
| S9898 | 2024.07.12 | 3 | 2 | S32E81 | 0070 | DAO |
 |
||||
| Total spot count: | 82 | 314 | 150 | ||||||||
| Sunspot number: | 162 | 484 | 280 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 112 | 359 | 195 | (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): | 178 | 266 | 224 | ||||||||
| 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 | 179.4 (1) | 57.2 (2A) / 147.8 (2B) / 167.3 (2C) | (134.7 projected, -0.2) | (5.7) | |
| 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.
