The geomagnetic field was at quiet to active levels on October 9 under the influence of effects from CH1246. Solar wind speed at SOHO ranged between 422 and 525 km/sec. The high latitude magnetometer at Andenes recorded unsettled to major storm levels. The above 10 MeV proton flux was at 840 pfu at the end of the day having peaked at 1140 pfu at 22:15 UT.
Solar flux density measured at 20h UT on 2.8 GHz was 220.3 - increasing 19.1 over the previous solar rotation. The Potsdam WDC planetary A index was 18 (STAR Ap - based on the mean of three hour interval ap indices: 17.9). Three hour interval K indices: 44433222 (planetary), 45544322 (Boulder), 56434445 (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 15 active regions using 2K resolution (SN: 341) and in 12 active regions using 1K resolution (SN: 221) SDO/HMI images.
AR 13842 [S12W84] rotated mostly out of view
and produced 2 major flares.
AR 13847 [S29W37] decayed slowly and quietly.
AR 13848 [N12W22] produced an X1 flare with a
very fast associated CME.
AR 13849 [S08E00] gained spots but lost the magnetic delta after
producing a minor M class flare.
AR 13850 [S10W04] decayed slowly and quietly.
AR 13852 [S12E41] was mostly unchanged and
remains capable of producing a minor M class flare.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10190 [S14W73] was quiet and stable.
S10200 [S22W17] was quiet and stable.
S10206 [N19W13] was quiet and stable.
S10208 [S22E01] reemerged with tiny spots.
S10209 [N18E45] was quiet and stable.
S10213 [S10E60] was quiet and stable.
S10214 [S07E50] developed quickly and was
quiet.
New region
S10216 [S15E73] rotated into view with tiny spots.
New region S10217 [S43E17] emerged with a tiny spot at a high
latitude.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.0 | 00:13 | 13842 | GOES16 | ||
| C3.7 | 00:42 | 13849 | GOES16 | ||
| X1.8 | 01:55 | 13848 | GOES16 | very fast full halo CME strong type IV and II radio sweeps |
|
| M1.6 | 05:46 | 13849 | GOES16 | ||
| C9.6 | 06:44 | 13842 | GOES16 | ||
| C9.0 | 07:30 | 13842 | GOES16 | ||
| C6.3 | 09:58 | S11W83 | 13842 | GOES16 | |
| C6.1 | 10:56 | 13852 | GOES16 | simultaneous flare in AR 13842 | |
| C4.3 | 11:33 | 13842 | GOES16 | ||
| C4.3 | 13:20 | GOES16 | |||
| C4.7 | 13:37 | GOES16 | |||
| C4.1 | 15:07 | GOES16 | |||
| X1.4/1N | 15:47 | 13842 | GOES16 | weak type IV radio sweep | |
| C5.0 | 16:43 | 13852 | GOES16 | ||
| C7.5 | 20:14 | S19W86 | 13842 | GOES16 | |
| C4.3 | 21:17 | 13842 | GOES16 | ||
| M7.7 | 23:12 | 13842 | GOES16 |
October 7: A full halo CME was observed after the M7 and X1 LDEs in
AR 13844. While Earth is not in the path of the CME core, there is a chance
of a solar wind shock on October 11.
October 8: A partial halo CME was observed from 05:12 UT in LASCO
imagery after a large filament eruption in the southwest quadrant. This CME
could reach Earth on October 11.
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 October 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 10-11 due to CME effects. October 12 could see quiet to active levels .
| 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 | ||||||||||
| 13842 | 2024.09.27 2024.09.28 |
9 | 3 | 1 | S13W90 | 0630 | EKI | HKX |
 |
 |
location: S12W84 |
| 13847 | 2024.09.30 2024.10.01 |
4 | S27W52 | 0005 | BXO |
 |
location: S29W37 |
||||
| 13848 | 2024.10.01 2024.10.02 |
14 | 39 | 18 | N12W25 | 0600 | DKI | DKC |
 |
 |
beta-gamma-delta area: 1070 location: N12W22 |
| S10190 | 2024.10.02 | 4 | 3 | S14W73 | 0040 | CRO |
 |
 |
|||
| 13849 | 2024.10.03 2024.10.04 |
18 | 58 | 40 | S07W02 | 0240 | EAI | DKI |
 |
 |
beta-gamma location: S08E00 area: 0610 |
| S10193 | 2024.10.03 | S22W42 | |||||||||
| 13851 | 2024.10.03 2024.10.07 |
S08W41 |
 |
location: S11W38 | |||||||
| S10196 | 2024.10.05 | N13W09 | |||||||||
| S10198 | 2024.10.05 | N13W41 | |||||||||
| S10200 | 2024.10.05 | 7 | 1 | S22W17 | 0010 | BXO |
 |
 |
|||
| 13850 | 2024.10.06 2024.10.06 |
8 | 13 | 8 | S10W06 | 0100 | CAO | CAO |
 |
 |
location: S10W04 area: 0200 |
| 13852 | 2024.10.06 | 8 | 32 | 18 | S14E40 | 0350 | DKI | EKI |
 |
 |
location: S12E41 area: 0600 |
| S10206 | 2024.10.06 | 8 | 3 | N19W13 | 0020 | BXO |
 |
||||
| S10209 | 2024.10.08 | 4 | 3 | N18E45 | 0020 | CRO |
 |
 |
|||
| S10212 | 2024.10.08 | N29E09 |
 |
||||||||
| S10213 | 2024.10.08 | 2 | S10E60 | 0002 | AXX |
 |
 |
||||
| S10214 | 2024.10.08 | 10 | 4 | S07E50 | 0130 | DAO |
 |
 |
|||
| S10215 | 2024.10.08 | N13E10 |
 |
||||||||
| S10216 | 2024.10.09 | 3 | 2 | S15E73 | 0010 | BXO |
 |
||||
| S10217 | 2024.10.09 | 1 | S43E17 | 0001 | AXX |
 |
|||||
| S10218 | 2024.10.09 | 3 | 1 | S22E01 | 0007 | AXX |
 |
||||
| Total spot count: | 57 | 191 | 102 | ||||||||
| Sunspot number: | 107 | 341 | 222 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 97 | 247 | 158 | (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): | 118 | 188 | 178 | ||||||||
| 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 | 261.4 (1) | 50.8 (2A) / 175.1 (2B) / 196.4 (2C) | (165.4 projected, +2.3) | (19.2) | |
| 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.
