The geomagnetic field was at quiet to active levels on October 31. A solar wind transient was observed beginning near 17h UT at ACE and the total field of the IMF reached 10 nT later in the day. Solar wind speed at SOHO ranged between 443 and 630 km/sec, averaging 550 km/sec (+10 compared to the previous day). The high latitude magnetometer at Andenes recorded quiet to major storm levels. The above 10 MeV proton flux was at 13 pfu at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 269.9 - decreasing 21.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 183.10. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 183.10 on May 2, 2024). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.3). Three hour interval K indices: 11111234 (planetary), 11112333 (Boulder), 21011336 (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 17 active regions using 2K resolution (SN: 476) and in 15 active regions using 1K resolution (SN: 291) SDO/HMI images.
AR 13868 [S11W59] was quiet and stable.
AR 13869 [S18W32] decayed further and merged with AR 13872. A small
magnetic delta configuration formed.
AR 13873 [S16W21] decayed slowly and quietly.
AR 13874 [N24W58] decayed slowly and quietly.
AR 13875 [N28W40] developed further and has minor polarity
intermixing.
AR 13876 [S04W46] decayed slowly. The spots immediately to the south
of this region were split off into a separate spot group.
AR 13877 [S15W04] was mostly quiet and stable.
AR 13878 [N16E26] developed further and has magnetic delta
configurations both in the northwestern and eastern part of the largest
penumbra. Further major flares are likely.
AR 13879 [N14E49] was quiet and stable.
New AR 13880 [S13E55] rotated into view on October 28 and was
numbered by SWPC 2 days later.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10279 [N13W43] decayed slowly and quietly.
S10295 [N11W17] was quiet and stable.
S10300 [S09E59] decayed slowly and quietly.
S10301 [S09E39] developed slowly and quietly.
New region S10303 [S09W48] was split off from AR 13876 as development
continued. The spot group has polarity intermixing. Minor M class flares are
possible.
New region S10304 [S11E23] was observed with tiny spots in an old
plage area.
New region S10305 [S14E07] was observed with tiny spots in an old
plage area.
C2+ flares
Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
C9.3 | 00:51 | S09W31 | S10303 | GOES16 | |
C4.2 | 01:51 | S10303 | GOES16 | ||
M1.0 | 02:52 | N15E36 | 13878 | GOES16 | |
M1.0 | 03:30 | N15E36 | 13878 | GOES16 | |
C5.1 | 04:28 | 13878 | GOES16 | ||
C5.6 | 05:11 | S10303 | GOES16 | simultaneous flare in AR 13878 | |
C6.7 | 05:54 | 13878 | GOES16 | simultaneous flare in AR S10303 | |
C4.9 | 06:25 | 13878 | GOES16 | ||
C3.4 | 07:35 | 13878 | GOES16 | ||
C6.2 | 08:31 | S10303 | GOES16 | ||
C5.5 | 08:45 | 13878 | GOES16 | ||
C7.6 | 09:04 | S10303 | GOES16 | ||
C7.1 | 09:29 | 13878 | GOES16 | ||
M1.4/1F | 09:37 | N17E36 | 13878 | GOES16 | |
M1.2 | 09:43 | 13878 | GOES16 | ||
M1.1 | 09:50 | 13878 | GOES16 | ||
C9.2 | 09:55 | 13878 | GOES16 | ||
C6.4 | 10:23 | 13878 | GOES16 | ||
C9.1 | 10:27 | 13878 | GOES16 | ||
C7.4 | 10:35 | 13878 | GOES16 | ||
C3.4 | 11:31 | S10303 | GOES16 | ||
C3.2 | 12:05 | S10303 | GOES16 | ||
M2.4/1N | 12:54 | N27W35 | 13875 | GOES16 | simultaneous flare in AR 13877 |
C5.1 | 13:34 | 13878 | GOES16 | ||
M1.2 | 13:59 | S10303 | GOES16 | ||
C6.0 | 14:37 | S10303 | GOES16 | simultaneous flare in AR 13875 | |
C3.5 | 15:19 | 13876 | GOES16 | ||
C3.2 | 16:02 | S10303 | GOES16 | ||
C4.1 | 16:58 | 13876 | GOES16 | ||
C4.3 | 17:17 | 13878 | GOES16 | ||
C3.5 | 18:16 | S10303 | GOES16 | ||
C4.7 | 18:29 | S10303 | GOES16 | ||
C4.8 | 18:36 | S10303 | GOES16 | ||
M1.0/2N | 19:07 | S10303 | GOES16 | ||
C4.9 | 19:37 | 13878 | GOES16 | ||
C6.3 | 20:25 | 13876 | GOES16 | ||
M4.6 | 21:10 | N18E24 | 13878 | GOES16 | |
X2.0 | 21:20 | 13878 | GOES16 | ||
M9.4 | 21:54 | 13878 | GOES16 | ||
M2.7 | 22:48 | S10303 | GOES16 |
October 30-31: No obviously Earth directed CMEs were observed.
October 29: A large filament in the southwestern quadrant erupted
around noon. A partial halo CME was observed afterwards, and there is a
slight chance components of the CME could reach Earth on November 1-2.
[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 positive polarity northern hemisphere coronal hole (CH1251) rotated across the central meridian on October 30-31. A positive polarity trans equatorial coronal hole (CH1252) will be Earth facing on October 31 - November 1.
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 quiet to unsettled on November 1-4, on Nov. 2-3 due to effects from CH1251 and on November 3-4 with effects from CH1252 dominating.
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 | ||||||||||
13865 | 2024.10.19 2024.10.20 |
S22W86 | |||||||||
13866 | 2024.10.20 2024.10.21 |
S12W78 | |||||||||
13868 | 2024.10.21 2024.10.21 |
1 | 1 | 1 | S11W59 | 0150 | HSX | HSX |
area: 0220 |
||
13869 | 2024.10.22 2024.10.23 |
12 | 38 | 23 | S18W33 | 0260 | DKC | ESC |
beta-gamma-delta location: S18W32 |
||
13875 | 2024.10.23 2024.10.24 |
15 | 26 | 13 | N28W41 | 0150 | DAI | DAI |
beta-gamma location: N28W40 area: 0230 |
||
S10272 | 2024.10.23 | N18W57 | |||||||||
13872 | 2024.10.23 2024.10.24 |
6 | S17W24 | 0240 | DKO |
merged with AR 13869 on 2024.10.31 |
|||||
13871 | 2024.10.24 | S09W50 | part of AR 13869 | ||||||||
13873 | 2024.10.24 2024.10.24 |
4 | 47 | 17 | S12W15 | 0040 | HAX | DKO |
location: S16W21 area: 0380 SWPC data has the leader spot as part of AR 13872 |
||
S10278 | 2024.10.24 | S22W20 | |||||||||
S10279 | 2024.10.24 | 1 | N13W43 | 0001 | AXX | ||||||
13874 | 2024.10.24 2024.10.25 |
7 | 19 | 9 | N25W60 | 0200 | EAI | EAI |
location: N24W58 area: 0250 |
||
S10282 | 2024.10.25 | N11W49 | |||||||||
13876 | 2024.10.25 2024.10.25 |
18 | 40 | 14 | S06W46 | 0200 | DKI | DAI |
beta-gamma location: S04W46 area: 0280 SWPC mismatch between area and classification |
||
S10284 | 2024.10.25 | S15W08 | |||||||||
13877 | 2024.10.25 2024.10.27 |
1 | 14 | 5 | S16W04 | 0010 | AXX | CRO |
area: 0025 location: S15W04 |
||
13878 | 2024.10.26 2024.10.27 |
11 | 53 | 32 | N16E23 | 0400 | EKI | EKC |
beta-gamma-delta location: N16E26 area: 0560 |
||
S10290 | 2024.10.26 | S21W59 | |||||||||
S10291 | 2024.10.27 | N24W56 | |||||||||
S10292 | 2024.10.27 | N16E06 | |||||||||
13879 | 2024.10.28 2024.10.29 |
1 | 11 | 5 | N15E50 | 0570 | HHX | CKO |
location: N14E49 area: 0870 |
||
S10295 | 2024.10.28 | 5 | 1 | N11W17 | 0010 | AXX | |||||
S10296 | 2024.10.28 | S01W04 | |||||||||
S10297 | 2024.10.29 | S12E05 | |||||||||
13880 | 2024.10.29 2024.10.31 |
1 | 9 | 6 | S13E55 | 0010 | AXX | CRO | area: 0025 | ||
S10299 | 2024.10.30 | S12E13 | |||||||||
S10300 | 2024.10.30 | 2 | S09E59 | 0003 | AXX | ||||||
S10301 | 2024.10.30 | 7 | 2 | S09E39 | 0015 | BXO | |||||
S10303 | 2024.10.31 | 19 | 10 | S09W48 | 0150 | DAI | beta-gamma | ||||
S10304 | 2024.10.31 | 6 | 1 | S11E23 | 0012 | AXX | |||||
S10305 | 2024.10.31 | 8 | 2 | S14E07 | 0015 | AXX | |||||
Total spot count: | 77 | 306 | 141 | ||||||||
Sunspot number: | 187 | 476 | 291 | (total spot count + 10 * number of spotted regions) | |||||||
Weighted SN: | 147 | 372 | 207 | (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): | 206 | 262 | 233 |
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 | 144.4 (+3.1) | 9.69 |
2024.05 | 187.7 | 191.9 | 171.7 | (149.6 projected, +5.2) | 23.56 (SC25 peak) |
2024.06 | 184.3 | 190.2 | 164.2 | (153.5 projected, +3.9) | 10.24 |
2024.07 | 196.6 | 203.0 | 196.5 | (156.4 projected, +2.9) | 7.13 |
2024.08 | 246.1 (cycle peak) |
252.2 | 215.5 (SC25 peak) | (158.4 projected, +2.0) | 15.96 |
2024.09 | 195.7 | 197.8 | 141.4 | (161.1 projected, +2.7) | 15.36 |
2024.10 | 221.0 | 219.6 | 166.3 | (163.4 projected, +2.3) | 19.0 |
2024.11 | (1) | 0 (2A/2B) / 203.9 (2C) | (161.8 projected, -1.6) | () | |
2024.12 | (158.7 projected, -3.1) | ||||
2025.01 | (154.4 projected, -4.3) | ||||
2025.02 | (147.6 projected, -6.8) | ||||
2025.03 | (142.8 projected, -4.8) | ||||
2025.04 | (139.8 projected, -3.0) |
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 activity in October 2024 increased over September and looks to be headed for an SSN near 160. The average solar flux for October will become the second highest for a month during SC25. The above plot now displays the peak in 365d smoothed sunspot numbers in mid October. ISN has a peak on October 15, NOAA SN on October 14 while both the 1K and 2K SDO SN peaked on October 16. Assuming that the average sunspot number from October 2024 until April 14, 2025 becomes 150, we would be looking at a 365 days smoothed sunspot maximum of 164.5 centered on October 15. 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.