The geomagnetic field was at quiet to active levels on October 6. Solar wind speed at SOHO ranged between 390 and 579 km/sec. A solar wind shock was observed at SOHO at 06:48 UT, likely the arrival of the October 3 CME. Initially the Bz component of the interplanetary magnetic field was northwards, however, during the latter half of the day more frequent and longer lasting southward excursions caused an increase in geomagnetic disturbance levels. The high latitude magnetometer at Andenes recorded quiet to major storm 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 264.5 - increasing 49.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 178.49. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 178.49 on April 7, 2024). The Potsdam WDC planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 12.8). Three hour interval K indices: 10213334 (planetary), 11323334 (Boulder), 00122336 (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 20 active regions using 2K resolution (SN: 469) and in 19 active regions using 1K resolution (SN: 315) SDO/HMI images.
AR 13839 [S14W62] was quiet and stable.
AR 13841 [N12W59] decayed losing spots and area.
AR 13842 [S18W50] lost area and spots. There is still a strong
magnetic delta in the northern part of the main penumbra. A major flare is possible.
AR 13843 [S09W78] was mostly quiet and rotated partly out of view.
AR 13844 [S15W70] decayed slowly losing spots and area. A major flare
is still possible.
AR 13847 [S29E04] was quiet and stable.
AR 13848 [N12E16] decayed slowly and was mostly quiet.
AR 13849 [S07E41] was mostly quiet and stable.
New AR 13850 [S10E37] was split off from AR 13849.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10190 [S16W26] was quiet and stable.
S10192 [S09W44] reemerged with tiny spots.
S10193 [S22W03] was quiet and stable.
S10194 [S12E04] was quiet and stable.
S10195 [N17W33] reemerged with tiny spots.
S10199 [S28W66] was mostly quiet and stable.
S10200 [S20E19] was quiet and stable.
New region S10204 [S11E82] rotated partly into view with large spots.
New region S10205 [N15W25] emerged with tiny spots.
New region S10206 [N17E20] was observed with tiny spots to the north
of AR 13848.
New region S10207 [N09W48] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| M1.0 | 00:18 | 13842 | GOES16 | ||
| C8.8 | 00:32 | 13842 | GOES16 | ||
| C6.9 | 01:00 | 13844 | GOES16 | ||
| C8.1 | 01:23 | 13844 | GOES16 | simultaneous flare in AR 13849 | |
| C8.2 | 01:26 | behind northwest limb | 13845 | GOES16 | |
| C9.6 | 01:38 | 13844 | GOES16 | ||
| M1.0 | 01:45 | 13844 | GOES16 | ||
| C6.2 | 02:35 | 13842 | GOES16 | ||
| C5.3 | 02:50 | 13842 | GOES16 | ||
| C5.5 | 03:59 | 13844 | GOES16 | ||
| C4.5 | 04:45 | 13842 | GOES18 | ||
| C9.2 | 05:04 | 13842 | GOES18 | ||
| C7.4 | 05:37 | 13842 | GOES16 | smaller, simultaneous flare in AR 13844 | |
| C4.9 | 06:10 | 13849 | GOES16 | ||
| C5.2 | 06:17 | 13844 | GOES16 | ||
| C5.4 | 06:49 | 13844 | GOES16 | ||
| C5.4 | 06:57 | 13848 | GOES16 | ||
| C4.6 | 07:33 | 13844 | GOES16 | ||
| C4.7 | 07:49 | 13844 | GOES16 | ||
| C5.4 | 08:26 | 13844 | GOES16 | ||
| C4.7 | 09:32 | 13842 | GOES16 | ||
| C5.4 | 09:35 | 13848 | GOES16 | ||
| C4.0 | 10:30 | 13842 | GOES16 | ||
| C4.4 | 10:44 | 13842 | GOES16 | ||
| C4.2 | 11:15 | 13844 | GOES16 | ||
| C5.0 | 12:02 | 13842 | GOES16 | ||
| C4.8 | 13:17 | 13844 | GOES16 | ||
| C4.9 | 13:30 | 13842 | GOES16 | ||
| C5.1 | 13:40 | 13842 | GOES16 | ||
| C5.7 | 13:48 | 13844 | GOES16 | ||
| C5.3 | 14:17 | 13842 | GOES16 | ||
| C5.5 | 14:42 | 13850 | GOES16 | simultaneous flare in AR 13844 | |
| C6.6 | 15:06 | 13850 | GOES16 | ||
| M1.3 | 15:21 | S15W65 | 13844 | GOES16 | |
| C6.9 | 15:28 | 13844 | GOES16 | ||
| M1.1 | 16:45 | 13842 | GOES16 | ||
| C5.1 | 17:17 | 13842 | GOES16 | ||
| C4.6 | 17:52 | 13842 | GOES16 | ||
| C5.4 | 18:24 | 13843 | GOES16 | simultaneous flare in AR 13844 | |
| C5.1 | 18:37 | 13842 | GOES16 | ||
| M1.4 | 18:59 | 13842 | GOES16 | ||
| C8.7 | 19:06 | 13842 | GOES16 | ||
| C5.1 | 19:47 | 13844 | GOES16 | ||
| C7.1 | 20:21 | S16W71 | 13844 | GOES16 | |
| M1.5 | 21:17 | S14W57 | 13839 | GOES16 | |
| C3.9 | 23:52 | 13842 | GOES16 | ||
| C4.0 | 23:58 | 13842 | GOES16 |
October 4: At least a partial halo CME was observed after the M4
flare in AR 13842 early in the day. The CME could reach Earth on
October 7.
October 5-6: 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 small positive polarity trans equatorial coronal hole (CH1245) was in an Earth facing position on October 4.
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 to fair.
The geomagnetic field is expected to be at unsettled to minor storm levels on October 7 due to CME effects. Effects from CH1245 could reach Earth on October 8 and cause some unsettled and active intervals. Quiet to unsettled conditions are likely on October 9.
| 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 | ||||||||||
| 13841 | 2024.09.25 2024.09.28 |
6 | 17 | 8 | N12W65 | 0030 | DRI | DRO |
 |
 |
area: 0040 location: N12W59 |
| 13839 | 2024.09.26 2024.09.26 |
1 | 2 | 2 | S15W63 | 0020 | HSX | CSO |
 |
 |
area: 0060 location: S14W62 |
| 13842 | 2024.09.27 2024.09.28 |
23 | 50 | 27 | S16W50 | 0460 | EKI | EKC |
 |
 |
beta-gamma-delta area: 0890 location: S18W50 |
| S10171 | 2024.09.27 | S08W50 |
 |
||||||||
| 13843 | 2024.09.28 2024.09.29 |
3 | 4 | 3 | S10W83 | 0120 | DSO | HAX |
 |
 |
location: S09W78 area: 0060 |
| S10176 | 2024.09.28 | N17W25 | |||||||||
| S10178 | 2024.09.28 | S14W56 | |||||||||
| 13844 | 2024.09.29 2024.09.30 |
10 | 14 | 6 | S16W72 | 0600 | EKI | EKO |
 |
 |
beta-gamma location: S15W70 area: 0960 |
| S10180 | 2024.09.29 | N01W46 | |||||||||
| S10182 | 2024.09.30 | S07W24 | |||||||||
| 13847 | 2024.09.30 2024.10.01 |
13 | 6 | S27W10 | 0025 | BXO |
 |
 |
location: S29E04 |
||
| 13848 | 2024.10.01 2024.10.02 |
16 | 57 | 26 | N13E14 | 0900 | DKI | DKC |
 |
 |
beta-gamma-delta area: 1210 location: N12E16 |
| S10186 | 2024.10.01 | N17W28 | |||||||||
| S10188 | 2024.10.01 | S34W47 | |||||||||
| S10189 | 2024.10.02 | N10W48 | |||||||||
| S10190 | 2024.10.02 | 10 | 1 | S16W26 | 0020 | BXO |
 |
 |
|||
| 13849 | 2024.10.03 2024.10.04 |
22 | 36 | 23 | S06E37 | 0350 | DKI | DKC |
 |
 |
beta-gamma-delta location: S07E41 area: 0710 |
| S10192 | 2024.10.03 | 7 | 2 | S09W44 | 0020 | CRO |
 |
||||
| S10193 | 2024.10.03 | 9 | 2 | S22W03 | 0015 | BXO |
 |
 |
|||
| S10194 | 2024.10.03 | 6 | 2 | S12E04 | 0015 | CRO |
 |
 |
|||
| S10195 | 2024.10.04 | 2 | 1 | N17W33 | 0006 | AXX |
 |
||||
| S10196 | 2024.10.05 | N13E30 |
 |
||||||||
| S10198 | 2024.10.05 | N13W02 |
 |
||||||||
| S10199 | 2024.10.05 | 1 | 1 | S28W66 | 0004 | AXX |
 |
 |
|||
| S10200 | 2024.10.05 | 6 | 2 | S20E19 | 0010 | BXO |
 |
 |
|||
| 13850 | 2024.10.06 2024.10.06 |
6 | 18 | 7 | S03E33 | 0160 | DAI | DAO |
 |
was AR S10201 location: S10E37 area: 0240 SWPC location is way off |
|
| S10203 | 2024.10.06 | S42E45 |
 |
reversed polarities | |||||||
| S10204 | 2024.10.06 | 3 | 2 | S11E82 | 0520 | DKO |
 |
||||
| S10205 | 2024.10.06 | 2 | 1 | N15W25 | 0005 | BXO |
 |
||||
| S10206 | 2024.10.06 | 10 | 3 | N17E20 | 0020 | BXO |
 |
||||
| S10207 | 2024.10.06 | 2 | N09W48 | 0003 | BXO |
 |
|||||
| Total spot count: | 87 | 269 | 125 | ||||||||
| Sunspot number: | 167 | 469 | 315 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 145 | 343 | 199 | (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 | 258 | 252 | ||||||||
| 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 |
| 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 | 136.8 (+5.7) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 103.7 | 141.3 (+4.5) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (145.3 projected, +4.0) | 9.69 |
| 2024.05 | 187.7 | 191.9 | 171.7 | (151.6 projected, +6.3) | 23.56 (SC25 peak) |
| 2024.06 | 184.3 | 190.2 | 164.2 | (155.5 projected, +3.9) | 10.24 |
| 2024.07 | 196.6 |
203.0 | 196.5 | (158.4 projected, +2.9) | 7.13 |
| 2024.08 | 246.1 (cycle peak) |
252.2 | 215.5 (SC25 peak) | (160.4 projected, +2.0) | 15.96 |
| 2024.09 | 195.7 | 197.8 | 141.4 | (163.1 projected, +2.7) | 15.36 |
| 2024.10 | 277.3 (1) | 36.8 (2A) / 190.0 (2B) / 197.9 (2C) | (165.4 projected, +2.3) | (6.1) | |
| 2024.11 | (163.7 projected, -1.7) | ||||
| 2024.12 | (160.7 projected, -3.0) | ||||
| 2025.01 | (156.3 projected, -4.4) | ||||
| 2025.02 | (149.6 projected, -6.7) | ||||
| 2025.03 | (144.8 projected, -4.8) | ||||
| 2025.04 | (141.6 projected, -3.2) | ||||
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
September 2024 saw a significant decrease in sunspot numbers compared to the previous month, however, activity was still fairly high. The average solar flux for the month ranks as number 3 of all months during SC25. Taking into account that we started seeing high sunspot numbers April 14, 2024, the most likely candidate for solar maximum would be at or just after October 14, 2024. Assuming that the average sunspot number from now until April 14, 2025 becomes 150, we would be looking at a 365 days smoothed sunspot maximum of 164.5 centered on October 14. Should the average sunspot number for that period become 160 we would get a peak near 169.7.
--------------------------------------------------------------------------------------
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.
