The geomagnetic field was quiet on January 21. Solar wind speed at SOHO ranged between 324 and 395 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.
Solar flux density measured at 20h UT on 2.8 GHz was 178.5 - increasing 11.8 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 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.6). Three hour interval K indices: 01122111 (planetary), 11232212 (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 17 active regions using 2K resolution (SN: 366) and in 16 active regions using 1K resolution (SN: 262) SDO/HMI images.
Region 13549 [S21W53] was mostly quiet and stable.
C1 flares: C1.8 @ 21:18 UT
Region 13553 [N04W37] decayed further and was quiet.
Region 13555 [S12W12] decayed slowly and quietly.
Region 13556 [N15W01] was quiet and stable.
Region 13557 [S22E10] was quiet and stable.
Region 13559 [N26E20] developed further gaining area and was the
source of many C flares. The region has polarity intermixing and could
produce M flares. The proximity to AR S9346 further increases the likelihood
of flares and the two regions could merge into a larger group. C1 flares:
C1.9 @ 03:54, C1.5 @ 10:35, C1.8 @ 10:50, C1.6 @ 12:50, C1.9 @ 23:32 UT
Region 13560 [S10E21] lost some spots and was mostly quiet.
Region 13561 [S15W17] developed further and has polarity intermixing.
C1 flares: C1.6 @ 20:57, C1.8 @ 21:33 UT
Region 13562 [S08W27] was mostly quiet and stable.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9338 [N17W30] was quiet and stable.
S9346 [N28E30] developed further and produced several C flares. The
region was the source of an M1.5 flare at 06:22 UT on January 22. Further
flaring is likely due to the proximity with AR 13559. C1 flares: C1.5 @
08:21, C1.7 @ 09:18, C1.7 @ 10:13, C1.7 @ 15:15 UT
S9351 [S19W11] decayed slowly and quietly.
S9352 [S33W28] decayed slowly and quietly.
S9353 [N26W02] was quiet and stable.
New region S9356 [N14W71] emerged with a tiny spot.
New region S9357 [S17W14] emerged very close to AR 13561.
New region S9358 [N10E09] emerged with tiny spots.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.0 | 00:27 | 13559 | GOES16 | involved filaments southeast of the region. Partial halo CME | |
| C5.3 | 00:41 | 13559 | GOES16 | ||
| C4.8 | 01:38 | 13560 | GOES16 | ||
| C6.3/1F | 02:02 | 13559 | GOES16 | ||
| C2.4 | 03:16 | 13559 | GOES16 | ||
| C2.0 | 05:23 | 13559 | GOES16 | ||
| C2.2 | 07:44 | N25E30 | 13559 | GOES16 | |
| C2.0 | 08:40 | N25E30 | 13559 | GOES16 | |
| C2.5 | 11:37 | N29E36 | S9346 | GOES16 | |
| C2.2 | 15:25 | S9346 | GOES16 | ||
| C2.9 | 16:23 | 13559 | GOES16 | ||
| C2.8 | 17:02 | 13557 | GOES16 | ||
| C3.9 | 17:34 | 13559 | GOES16 | ||
| C5.8 | 18:38 | 13559 | GOES16 | ||
| C7.1 | 18:42 | 13559 | GOES16 | ||
| C2.7 | 19:28 | 13561 | GOES16 | ||
| C6.7 | 19:35 | 13559 | GOES16 | SWPC attributed this to smaller, preceding flare in AR 13561 | |
| C5.8 | 20:15 | S9346 | GOES16 | ||
| C2.7 | 21:51 | 13559 | GOES16 | ||
| C3.7 | 22:41 | S9346 | GOES16 |
January 19: No obviously Earth directed CME observed.
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.
[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 fair to good. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on January 22. Late on January 22 or early on January 23 the January 20 CME could reach Earth and cause unsettled to minor storm conditions. Quiet to unsettled is expected for January 24.
| 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 | ||||||||||
| 13545 | 2024.01.08 2024.01.09 |
1 | S06W91 | 0120 | HSX |
 |
rotated out of view | ||||
| 13551 | 2024.01.10 2024.01.12 |
N26W64 |
location: N27W62 |
||||||||
| 13548 | 2024.01.10 2024.01.12 |
N15W80 | location: N12W75 | ||||||||
| 13549 | 2024.01.10 2024.01.12 |
1 | 3 | 1 | S21W55 | 0170 | HSX | CHO |
 |
 |
area: 0320 location: S21W53 |
| 13553 | 2024.01.13 2024.01.13 |
1 | 7 | 4 | N05W38 | 0020 | HRX | CRO |
 |
 |
location: N04W37 |
| 13554 | 2024.01.13 2024.01.15 |
N07W31 |
location: N07W26 |
||||||||
| S9324 | 2024.01.13 | S19W24 | |||||||||
| 13555 | 2024.01.14 2024.01.15 |
5 | 12 | 5 | S12W09 | 0110 | CSO | CSO |
 |
 |
area: 0150 location: S12W12 |
| S9327 | 2024.01.14 | N12W54 | |||||||||
| S9328 | 2024.01.14 | N21W57 | |||||||||
| S9329 | 2024.01.15 | S19W11 | |||||||||
| 13556 | 2024.01.15 2024.01.16 |
1 | 7 | 3 | N15W01 | 0070 | HAX | CSO |
 |
 |
|
| 13557 | 2024.01.16 2024.01.16 |
7 | 2 | S13E04 | 0015 | AXX |
 |
 |
location: S22E10 |
||
| 13561 | 2024.01.16 2024.01.19 |
8 | 33 | 19 | S16W16 | 0090 | DRI | DAI |
 |
 |
beta-gamma area: 0270 location: S17W14 |
| S9333 | 2024.01.16 | N11W16 | |||||||||
| S9334 | 2024.01.16 | N13W48 | |||||||||
| 13559 | 2024.01.17 2024.01.18 |
28 | 48 | 30 | N27E22 | 0300 | EKC | EKI |
 |
 |
beta-gamma area: 0760 location: N26E20 |
| 13560 | 2024.01.17 2024.01.18 |
10 | 21 | 13 | S10E22 | 0060 | CRI | DRI |
 |
 |
location: S10E21 area: 0090 |
| S9337 | 2024.01.17 | S19W42 |
 |
||||||||
| S9338 | 2024.01.17 | 3 | 1 | N17W30 | 0005 | BXO |
 |
 |
|||
| S9339 | 2024.01.17 | N25W50 | |||||||||
| S9340 | 2024.01.17 | N11W27 | |||||||||
| S9341 | 2024.01.18 | S11W41 | |||||||||
| S9342 | 2024.01.18 | S10W16 | |||||||||
| S9343 | 2024.01.18 | N22E18 | |||||||||
| S9344 | 2024.01.18 | S02W35 | |||||||||
| S9346 | 2024.01.19 | 18 | 8 | N28E30 | 0070 | DAI |
 |
 |
beta-gamma | ||
| S9347 | 2024.01.19 | S23W26 |
 |
||||||||
| S9348 | 2024.01.19 | N12W31 |
 |
||||||||
| 13562 | 2024.01.20 2024.01.20 |
5 | 19 | 8 | S08W27 | 0110 | DAO | DAO |
 |
 |
area: 0180 |
| S9351 | 2024.01.20 | 2 | 1 | S19W11 | 0004 | AXX |
 |
 |
|||
| S9352 | 2024.01.20 | 2 | S33W28 | 0003 | AXX |
 |
 |
||||
| S9353 | 2024.01.20 | 3 | 1 | N26W02 | 0008 | AXX |
 |
 |
|||
| S9354 | 2024.01.20 | N11W56 |
 |
||||||||
| S9355 | 2024.01.20 | N14E19 |
 |
||||||||
| S9356 | 2024.01.21 | 1 | 1 | N14W71 | 0003 | AXX |
 |
||||
| S9357 | 2024.01.21 | 8 | 3 | S17W14 | 0030 | DRO |
 |
||||
| S9358 | 2024.01.21 | 2 | 2 | N10E09 | 0005 | BXO |
 |
||||
| Total spot count: | 60 | 196 | 102 | ||||||||
| Sunspot number: | 150 | 366 | 262 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 104 | 250 | 156 | (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 | 201 | 210 | ||||||||
| 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 | 168.3 (1) | 93.7 (2A) / 138.3 (2B) / 155.4 (2C) | (117.9 projected, -3.3) | (5.1) | |
| 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.
