The geomagnetic field was quiet to active on January 22. Solar wind speed at SOHO ranged between 360 and 465 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux lifted above background levels early in the day and increased slowly until reaching a peak of 7.1 pfu at 16:50 UT. What was likely the January 20 CME was observed reaching DSCOVR just after 16h UT and caused a relatively weak geomagnetic disturbance after 18h UT. The peak proton flux coincided with the time the CME reached Earth.
Solar flux density measured at 20h UT on 2.8 GHz was 196.1 - increasing 41.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 157.06. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 158.71 on June 27, 2023). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 8.8). Three hour interval K indices: 10112234 (planetary), 10112234 (Boulder), 10122123 (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: 395) and in 11 active regions using 1K resolution (SN: 244) SDO/HMI images.
Region 13549 [S21W67] was quiet and stable.
Region 13553 [N03W49] decayed further and could soon become spotless.
Region 13555 [S12W26] developed with new flux emerging to the south
of the leader spot.
Region 13556 [N15W14] decayed slowly and quietly.
Region 13557 [S21W02] was quiet and stable.
Region 13559 [N27E08] could produce major flares. The
spot group lost many intermediate spots. The complexity arises from the near merger with AR S9346 with the
leader spots of the latter region very close to the trailing spots of AR
13559. The total longitudinal span of the two regions is 22 degrees. C1
flares: C1.9 @ 09:13 UT
Region 13560 [S10E06] developed slowly and quietly. The region has
weak polarity intermixing.
Region 13561 [S15W31] developed further and has a weak magnetic delta
structure in the central spot section. Major flare are possible due to
possible interaction with nearby regions AR 13555 and S9357. The latitudinal
separation between ARs 13561 and S9357 is minimal and the two regions could
merge.
Region 13562 [S08W40] decayed slowly and quietly.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9338 [N30W41] decayed slowly and quietly.
S9346 [N28E18] is compact and has significant polarity intermixing.
The region gained spots and area and could produce a major flare itself or
with AR 13559.
S9351 [S20W23] decayed slowly and quietly.
S9357 [S17W30] developed and gained a magnetic
delta structure in the leading penumbra. Spots in this group and in AR 13561
are very close to each other and major flaring is possible.
New region S9360 [S09W21] emerged with tiny spots.
New region S9361 [S05W02] was observed with tiny spots in an
old plage area.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.3 | 00:13 | 13559 | GOES16 | ||
| C2.9 | 00:32 | N25E32 | 13559 | GOES16 | |
| C6.5 | 01:47 | N26E23 | 13559 | GOES16 | |
| C3.6 | 03:14 | 13559 | GOES16 | ||
| C3.3 | 03:28 | S9346 | GOES16 | ||
| C5.3 | 04:14 | S9346 | GOES16 | ||
| M1.5/1N | 06:22 | N29E27 | S9346 | GOES16 | |
| C3.7 | 07:04 | GOES16 | |||
| C5.2 | 07:28 | S9346 | GOES16 | ||
| C3.1 | 08:01 | 13559 | GOES16 | simultaneous flare in AR S9346 | |
| C5.8 | 08:25 | N28E24 | S9346 | GOES16 | |
| C2.2 | 09:39 | S9346 | GOES16 | ||
| C7.0 | 11:27 | S9357 | GOES16 | incorrectly attributed to AR 13559 by SWPC. Flare may have been triggered by filament eruption just south of this region | |
| C5.8 | 12:20 | S9346 | GOES16 | ||
| C5.5 | 12:31 | S9346 | GOES16 | ||
| C3.5 | 13:14 | 13559 | GOES16 | ||
| C2.6 | 14:38 | behind southwest limb | GOES16 | ||
| C3.3 | 15:41 | 13561 | GOES16 | ||
| C3.7 | 16:04 | S9346 | GOES16 | ||
| C7.0 | 16:49 | 13561 | GOES16 | ||
| C3.9 | 17:26 | S9346 | GOES16 | ||
| C5.2 | 17:48 | S9357 | GOES16 | ||
| C5.5 | 17:50 | S9346 | GOES16 | ||
| C5.3 | 18:04 | S9346 | GOES16 | ||
| C4.5 | 18:50 | S9346 | GOES16 | simultaneous flare in AR S9357 | |
| C8.1 | 19:05 | S9357 | GOES16 | ||
| M1.1 | 19:24 | 13559 | GOES16 | ||
| M1.2 | 19:32 | 13559 | GOES16 | simultaneous flare in AR 13561 | |
| M2.0/1F | 19:47 | 13561 | GOES16 | flare involved AR S9357 | |
| C3.4 | 20:52 | S9346 | GOES16 | ||
| M3.4 | 21:21 | 13561 | GOES16 | flare involved AR S9357 | |
| M2.5 | 21:27 | 13561 | GOES16 | flare involved AR S9357 | |
| M1.6 | 21:43 | S9357 | GOES16 | ||
| M2.1 | 22:22 | 13561 | GOES16 | simultaneous flare in AR S9357 | |
| C5.2 | 22:52 | 13555 | GOES16 | ||
| C4.5 | 23:14 | S9346 | GOES16 | ||
| C3.8 | 23:52 | S9357 |
January 20: A full halo CME was observed in LASCO imagery after a
C3.5 long duration event involving filament eruptions just south of AR
13555. The CME could reach Earth between late on January 22 and noon on
January 23.
January 21: A partial halo CME was observed after a C4 flare in
AR 13559, including filaments to the southeast, early in the day. There is a slight chance that the outer edge of
the CME could reach Earth.
January 22: A partial halo CME was observed after a large filament
eruption in the southwest quadrant after 09h UT. The CME could cause a
disturbance on January 25.
[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 negative polarity southern hemisphere coronal hole (CH1199) will likely become Earth facing on January 24-25.
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 quiet to unsettled on January 23 due to CME effects and quiet on January 24. Quiet to active is likely on January 25 due to CME effects.
| 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 | ||||||||||
| 13551 | 2024.01.10 2024.01.12 |
N26W78 |
location: N27W75 |
||||||||
| 13549 | 2024.01.10 2024.01.12 |
1 | 2 | 1 | S17W69 | 0160 | HSX | CKO |
 |
 |
area: 0340 location: S21W67 |
| 13553 | 2024.01.13 2024.01.13 |
1 | 3 | 1 | N05W51 | 0010 | AXX | BXO |
 |
 |
location: N03W49 area: 0005 |
| 13554 | 2024.01.13 2024.01.15 |
N07W46 |
location: N07W39 |
||||||||
| S9324 | 2024.01.13 | S19W37 | |||||||||
| 13555 | 2024.01.14 2024.01.15 |
2 | 22 | 8 | S12W26 | 0080 | HSX | DAO |
 |
 |
area: 0220 |
| S9329 | 2024.01.15 | S19W24 | |||||||||
| 13556 | 2024.01.15 2024.01.16 |
2 | 6 | 4 | N17W16 | 0040 | HAX | HAX |
 |
 |
location: N15W14 |
| 13557 | 2024.01.16 2024.01.16 |
5 | S13W10 | 0012 | AXX |
 |
 |
location: S21W02 |
|||
| 13561 | 2024.01.16 2024.01.19 |
14 | 45 | 27 | S15W28 | 0090 | DAI | DAC |
 |
 |
beta-gamma-delta area: 0350 location: S15W31 |
| S9333 | 2024.01.16 | N11W29 | |||||||||
| 13559 | 2024.01.17 2024.01.18 |
32 | 36 | 23 | N27E11 | 0360 | FKC | EKO |
 |
 |
beta-gamma area: 0820 location: N27E08 SWPC includes AR S9346 |
| 13560 | 2024.01.17 2024.01.18 |
4 | 34 | 20 | S11E08 | 0040 | CAO | DRI |
 |
 |
beta-gamma location: S10E07 area: 0110 |
| S9337 | 2024.01.17 | S19W55 | |||||||||
| S9338 | 2024.01.17 | 1 | N30W41 | 0001 | AXX |
 |
 |
||||
| S9340 | 2024.01.17 | N11W40 | |||||||||
| S9341 | 2024.01.18 | S11W54 | |||||||||
| S9342 | 2024.01.18 | S10W29 | |||||||||
| S9343 | 2024.01.18 | N22E05 | |||||||||
| S9344 | 2024.01.18 | S02W48 | |||||||||
| S9346 | 2024.01.19 | 37 | 22 | N28E18 | 0270 | DAC |
 |
 |
beta-gamma | ||
| S9347 | 2024.01.19 | S23W39 | |||||||||
| S9348 | 2024.01.19 | N12W44 | |||||||||
| 13562 | 2024.01.20 2024.01.20 |
3 | 15 | 9 | S09W42 | 0090 | DAO | DAO |
 |
 |
location: S08W40 |
| S9351 | 2024.01.20 | 3 | S20W23 | 0003 | AXX |
 |
 |
||||
| S9352 | 2024.01.20 | S33W41 |
 |
||||||||
| S9353 | 2024.01.20 | N26W15 |
 |
||||||||
| S9355 | 2024.01.20 | N14E06 | |||||||||
| S9357 | 2024.01.21 | 28 | 17 | S17W30 | 0130 | DAC |
 |
 |
beta-gamma-delta | ||
| S9358 | 2024.01.21 | N10W04 |
 |
||||||||
| S9360 | 2024.01.22 | 5 | 2 | S09W21 | 0012 | CRO |
 |
||||
| S9361 | 2024.01.22 | 3 | S05W02 | 0006 | AXX |
 |
|||||
| Total spot count: | 59 | 245 | 134 | ||||||||
| Sunspot number: | 139 | 395 | 244 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 99 | 301 | 190 | (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): | 153 | 217 | 195 | ||||||||
| 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 |
| 2022.05 | 133.8 | 136.8 | 96.5 | 77.4 (+4.4) | 7.48 |
| 2022.06 | 116.1 | 119.8 | 70.3 | 81.1 (+3.7) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | 86.7 (+5.6) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 74.6 | 92.6 (+5.9) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | 96.5 (+3.9) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.9 (+2.4) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.2 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.7 (+5.5) | 10.99 |
| 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 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 123.3 | 121.0 (+3.2) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 97.6 | 122.7 (+1.7) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.4 | 123.9 (+1.2) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.0 (+1.1) (SC25 solar max candidate) |
8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | (124.6 projected, -0.4) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | (124.1 projected, -0.5) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | (123.8 projected, -0.3) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | (124.6 projected, +0.8) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | (124.6 projected, +0.0) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | (121.2 projected, -3.4) | 9.60 |
| 2024.01 | 169.6 (1) | 98.2 (2A) / 138.3 (2B) / 157.1 (2C) | (117.9 projected, -3.3) | (5.3) | |
| 2024.02 | (117.1 projected, -0.8) | ||||
| 2024.03 | (116.6 projected, -0.5) | ||||
| 2024.04 | (116.6 projected, +0.0) | ||||
| 2024.05 | (117.0 projected, -0.8) | ||||
| 2024.06 | (114.9 projected, -2.1) | ||||
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
The relatively low solar activity during the last months of 2023 significantly increased the possibility that solar cycle 25 has already peaked. Whether the first peak in June 2023 will be the actual solar max will not be known for some time. Due to the relatively high solar activity early in 2023 it is unlikely there will be another solar max candidate, if at all, until at least May 2024. Both the northern and southern polar fields, as well as the averaged total field, have already reversed polarities.
--------------------------------------------------------------------------------------
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.
