The geomagnetic field was at quiet levels on October 13. Solar wind speed at SOHO ranged between 413 and 543 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled 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 194.9 - increasing 25.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 179.65. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 179.65 on April 13, 2024). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.6). Three hour interval K indices: 10012121 (planetary), 111223** (Boulder), 10022232 (Andenes).
The background x-ray flux is at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 17 active regions using 2K resolution (SN: 352) and in 14 active regions using 1K resolution (SN: 225) SDO/HMI images.
AR 13848 [N15W75] decayed slowly as it
approached the northwest limb. An M3.4 flare was recorded at 00:17 UT on
October 14.
AR 13849 [S06W53] produced a few C flares and decayed slowly. C1
flares: C1.8 @ 20:15 UT
AR 13850 [S08W58] was quiet and stable.
AR 13852 [S11W11] was mostly quiet and stable. C1 flares: C1.6 @
22:42 UT
AR 13853 [N20W08] was quiet and stable.
AR 13854 [S06W03] was mostly quiet and stable.
New AR 13855 [N16W34] emerged on October 12 and was numbered by SWPC
the next day. C1 flares: C1.7 @ 16:48 UT
New AR 13856 [N09E32] rotated into view on October 10 and received
its NOAA number 3 days later.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10213 [S13E06] was quiet and stable.
S10220 [S12W50] was quiet and stable.
S10231 [N15E34] was quiet and stable.
New region S10233 [S15E73] rotated into view
with small spots.
New region S10234 [S06E30] was observed with tiny spots in an old
plage area.
New region S10235 [S07E83] rotated into view with a few spots.
New region S10236 [N02E24] emerged with a tiny spot.
New region S10237 [N33E37] emerged with tiny spots.
New region S10238 [S22E21] was observed with
tiny spots in an old plage area.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment| |
| C2.4 | 01:12 | 13848 | GOES16 | ||
| C2.5 | 01:42 | southeast limb | S10233 | GOES16 | simultaneous flare in AR 13852 |
| C2.7 | 01:48 | 13848 | GOES16 | ||
| C3.0 | 03:33 | 13849 | GOES16 | ||
| C2.5 | 05:05 | 13852 | GOES16 | ||
| C4.0 | 05:32 | 13852 | GOES16 | ||
| C4.1 | 05:39 | 13852 | GOES16 | ||
| C4.2 | 06:01 | 13856 | GOES16 | ||
| C5.7 | 06:57 | N18W63 | 13848 | GOES16 | |
| C3.3 | 07:34 | 13848 | GOES16 | ||
| C2.2 | 08:29 | 13854 | GOES16 | ||
| C2.6 | 09:29 | 13854 | GOES16 | ||
| C2.0 | 12:22 | 13854 | GOES16 | ||
| C2.8 | 15:16 | 13849 | GOES16 | ||
| C2.6 | 16:23 | 13848 | GOES16 | ||
| C2.7 | 17:31 | 13854 | GOES16 | ||
| C2.1 | 18:52 | 13855 | GOES16 | ||
| C2.0 | 23:33 | 13855 | GOES16 |
October 12-14: 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) was in an Earth facing position on October 12. Another positive polarity northern hemisphere coronal hole (CH1247) could rotate across the central meridian on October 14-16.
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.
The geomagnetic field is expected to be at mostly quiet levels on October 14-17. There is a chance of unsettled intervals on Oct.15 due to effects from CH1246. Effects from CH1247 could cause quiet to active levels on October 18-20.
| 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 | ||||||||||
| 13848 | 2024.10.01 2024.10.02 |
4 | 8 | 6 | N13W79 | 0350 | DHI | DKO |
 |
 |
area: 0800 location: N14W75 |
| 13849 | 2024.10.03 2024.10.04 |
5 | 26 | 13 | S06W56 | 0240 | DAI | CSI |
 |
 |
beta-gamma location: S06W53 area: 0320 |
| 13850 | 2024.10.06 2024.10.06 |
1 | 1 | 1 | S08W57 | 0090 | HSX | HSX |
 |
 |
area: 0130 |
| 13852 | 2024.10.06 | 8 | 43 | 19 | S10W15 | 0300 | DKI | DKI |
 |
 |
beta-gamma-delta location: S11W11 area: 0630 |
| 13853 | 2024.10.08 2024.10.10 |
9 | 5 | N22W05 | 0015 | BXO |
 |
 |
location: N20W08 |
||
| S10212 | 2024.10.08 | N29W43 | |||||||||
| S10213 | 2024.10.08 | 6 | 1 | S13E06 | 0010 | BXO |
 |
 |
|||
| 13854 | 2024.10.08 2024.10.10 |
15 | 39 | 22 | S04W05 | 0260 | EKI | EKI |
 |
 |
beta-gamma location: S06W03 area: 0600 |
| S10215 | 2024.10.08 | N20W38 | |||||||||
| S10216 | 2024.10.09 | S15E19 | |||||||||
| S10217 | 2024.10.09 | S43W35 | |||||||||
| S10218 | 2024.10.09 | S23W40 | |||||||||
| S10220 | 2024.10.10 | 4 | 1 | S12W50 | 0015 | CRO |
 |
 |
|||
| S10222 | 2024.10.10 | N28W46 | |||||||||
| 13856 | 2024.10.10 2024.10.13 |
1 | 5 | 3 | N09E37 | 0010 | BXO | CRO |
 |
 |
location: N09E32 |
| S10225 | 2024.10.11 | S09W28 |
 |
||||||||
| S10227 | 2024.10.11 | N12W22 | |||||||||
| S10228 | 2024.10.11 | N47W06 | |||||||||
| 13855 | 2024.10.12 2024.10.13 |
4 | 12 | 7 | N14W33 | 0020 | CSO | DRI |
 |
 |
location: N16W34 area: 0050 |
| S10230 | 2024.10.12 | N10E42 |
 |
||||||||
| S10231 | 2024.10.12 | 6 | N15E34 | 0008 | BXO |
 |
 |
||||
| S10232 | 2024.10.12 | N27W01 |
 |
||||||||
| S10233 | 2024.10.13 | 3 | 2 | S15E73 | 0060 | CAO |
 |
||||
| S10234 | 2024.10.13 | 7 | 2 | S06E30 | 0015 | BXO |
 |
||||
| S10235 | 2024.10.13 | 3 | 2 | S07E83 | 0150 | DAO |
 |
||||
| S10236 | 2024.10.13 | 1 | N02E24 | 0001 | AXX |
 |
|||||
| S10237 | 2024.10.13 | 4 | N33E37 | 0006 | BXO |
 |
|||||
| S10238 | 2024.10.13 | 5 | 1 | S22E21 | 0010 | BXO |
 |
||||
| Total spot count: | 38 | 182 | 85 | ||||||||
| Sunspot number: | 108 | 352 | 225 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 83 | 241 | 144 | (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): | 119 | 194 | 180 | ||||||||
| 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 | 245.5 (1) | 66.4 (2A) / 158.4 (2B) / 200.4 (2C) | (165.4 projected, +2.3) | (25.3) | |
| 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.
