The geomagnetic field was at quiet to extreme storm levels on October 10. A very strong solar wind shock was observed at SOHO at 14:44 UT, the arrival of the October 9 CME. Solar wind speed at SOHO ranged between 397 and 831 km/sec. The high latitude magnetometer at Andenes recorded quiet to very severe storm levels. The above 10 MeV proton flux was at 10.5 pfu at the end of the day having peaked at 1810 pfu at 15:15 UT.
Solar flux density measured at 20h UT on 2.8 GHz was 216.3 - increasing 30.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 179.20. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 179.20 on April 11, 2024). The Potsdam WDC planetary A index was 97 (STAR Ap - based on the mean of three hour interval ap indices: 97.3). Three hour interval K indices: 23234889 (planetary), 22124868 (Boulder), 34235857 (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 18 active regions using 2K resolution (SN: 394) and in 12 active regions using 1K resolution (SN: 218) SDO/HMI images.
AR 13848 [N12W36] decayed slowly and was mostly
quiet.
AR 13849 [S07W12] decayed losing all penumbra on the positive
polarity spots.
AR 13850 [S09W17] decayed slowly and quietly.
AR 13852 [S12E28] was mostly unchanged and
remains capable of producing a minor M class flare.
New AR 13853 [N18E31] emerged on October 8 and was numbered by SWPC 2
days later.
New AR 13854 [S07E37] emerged on October 8 and developed quickly on
October 9 and 10. SWPC numbered the region on October 10. A minor M class
flare is possible.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10200 [S17W27] was quiet and stable.
S10213 [S13E47] was quiet and stable.
S10215 [N14W01] was quiet and stable.
S10216 [S15E58] was quiet and stable.
S10218 [S23W12] was quiet and stable.
New region S10219 [N02W64] emerged with tiny spots.
New region S10220 [S14W10] emerged with several spots.
New region S10221 [N23W44] emerged with a tiny spot.
New region S10222 [N28W07] emerged with a tiny spot.
New region S10223 [N12E79] rotated into view with tiny spots.
New region S10224 [S37W31] was observed with tiny spots in an old
plage area.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C6.1 | 00:15 | 13849 | GOES16 | ||
| C5.1 | 00:24 | 13842 | GOES16 | ||
| C5.8 | 01:55 | 13842 | GOES16 | ||
| C4.5 | 02:51 | 13842 | GOES16 | ||
| C4.8 | 03:02 | northeast limb | S10223 | GOES16 | |
| C4.1 | 04:12 | 13852 | GOES16 | ||
| C4.2 | 04:19 | behind southwest limb | 13842 | GOES16 | |
| C5.2 | 06:59 | behind southwest limb | 13842 | GOES16 | simultaneous flare in AR 13854 |
| C5.1 | 07:15 | 13854 | GOES16 | ||
| C5.7 | 07:56| | behind southwest limb | 13842 | GOES16 | |
| C7.3 | 08:35 | behind southwest limb | 13842 | GOES16 | |
| C4.4 | 10:55 | 13852 | GOES16 | ||
| M1.3 | 12:00 | behind southwest limb | 13842 | GOES16 | |
| M1.1 | 12:18 | behind southwest limb | 13842 | GOES16 | dual flare centers |
| M1.2 | 12:25 | 13852 | GOES16 | ||
| C6.1 | 13:21 | 13849 | GOES16 | ||
| C7.5 | 14:40 | behind southwest limb | 13842 | GOES16 | |
| C5.6 | 15:15 | behind southwest limb | 13842 | GOES16 | |
| M1.0 | 17:00 | behind southwest limb | 13842 | GOES16 | |
| C4.0 | 17:31 | behind southwest limb | 13842 | GOES16 | |
| C4.2 | 18:05 | behind southwest limb | 13842 | GOES16 | |
| C4.0 | 18:39 | behind southwest limb | 13842 | GOES16 | |
| C3.8 | 19:24 | behind southwest limb | 13842 | GOES16 | |
| C4.2 | 19:38 | 13849 | GOES16 | ||
| C7.5 | 21:50 | 13852 | GOES16 | simultaneous flare in AR 13842 | |
| M3.0 | 22:28 | behind southwest limb | 13842 | GOES16 | LDE |
October 9: A full halo CME was observed after the X1 flare in AR
13848 early in the day. This CME was observed arriving at SOHO at 14:44 UT
on October 10.
October 10: No obviously Earth directed CMEs were 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 northern hemisphere coronal hole (CH1246) will likely rotate into an Earth facing position on October 12-13. Another positive polarity northern hemisphere coronal hole (CH1247) could rotate across the central meridian on Octber 15-16.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is very poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be at active to very severe storm levels on October 11. October 12 could see quiet to active levels with disturbance levels decreasing to quiet to unsettled on October 13.
| 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 | ||||||||||
| 13847 | 2024.09.30 2024.10.01 |
S27W66 |
location: S29W50 |
||||||||
| 13848 | 2024.10.01 2024.10.02 |
20 | 29 | 15 | N13W39 | 0600 | DKI | DKI |
 |
 |
beta-gamma area: 1040 location: N12W36 |
| 13849 | 2024.10.03 2024.10.04 |
25 | 51 | 22 | S06W16 | 0240 | DAI | CAI |
 |
 |
beta-gamma location: S07W12 area: 0550 |
| S10193 | 2024.10.03 | S22W55 | |||||||||
| 13851 | 2024.10.03 2024.10.07 |
S08W55 | location: S11W51 | ||||||||
| S10196 | 2024.10.05 | N13W22 | |||||||||
| S10198 | 2024.10.05 | N13W54 | |||||||||
| S10200 | 2024.10.05 | 5 | 2 | S18W27 | 0010 | BXO |
 |
 |
|||
| 13850 | 2024.10.06 2024.10.06 |
4 | 11 | 6 | S08W19 | 0100 | CAO | HAX |
 |
 |
location: S09W17 area: 0180 |
| 13852 | 2024.10.06 | 20 | 37 | 23 | S10E26 | 0360 | DKI | EKI |
 |
 |
location: S12E28 area: 0640 |
| S10206 | 2024.10.06 | 5 | 2 | N18W29 | 0010 | BXO |
 |
 |
|||
| 13853 | 2024.10.08 2024.10.10 |
1 | 4 | 2 | N20E37 | 0010 | HRX | CRO |
 |
 |
area: 0020 location: N18E31 SWPC location is way off |
| S10212 | 2024.10.08 | N29W04 | |||||||||
| S10213 | 2024.10.08 | 4 | S13E47 | 0004 | BXO |
 |
 |
||||
| 13854 | 2024.10.08 2024.10.10 |
20 | 38 | 17 | S05E34 | 0150 | DAI | DAI |
 |
 |
location: S07E37 area: 0330 |
| S10215 | 2024.10.08 | 2 | 1 | N14W01 | 0004 | AXX |
 |
||||
| S10216 | 2024.10.09 | 4 | 2 | S15E58 | 0007 | BXO |
 |
 |
|||
| S10217 | 2024.10.09 | S43E04 |
 |
||||||||
| S10218 | 2024.10.09 | 3 | S23W01 | 0006 | AXX |
 |
 |
||||
| S10219 | 2024.10.10 | 3 | 2 | N02W64 | 0010 | BXO |
 |
||||
| S10220 | 2024.10.10 | 12 | 4 | S14W10 | 0025 | CRO |
 |
||||
| S10221 | 2024.10.10 | 1 | N25W44 | 0001 | AXX |
 |
|||||
| S10222 | 2024.10.10 | 1 | N28W07 | 0002 | AXX |
 |
|||||
| S10223 | 2024.10.10 | 2 | N12E79 | 0003 | AXX |
 |
|||||
| S10224 | 2024.10.10 | 2 | S37W31 | 0005 | AXX |
 |
|||||
| Total spot count: | 90 | 214 | 98 | ||||||||
| Sunspot number: | 150 | 394 | 218 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 128 | 255 | 139 | (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): | 165 | 217 | 174 | ||||||||
| 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 | 256.9 (1) | 55.7 (2A) / 172.6 (2B) / 196.7 (2C) | (165.4 projected, +2.3) | (21.6) | |
| 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.
