The geomagnetic field was quiet on January 30, weakly under the influence of effects from CH1199. Solar wind speed at SOHO ranged between 451 and 529 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at 2 pfu at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 135.0 - decreasing 5.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 157.02. 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 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.4). Three hour interval K indices: 22221122 (planetary), 23321222 (Boulder), 33221254 (Andenes).
The background x-ray flux is at the class B7 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 198) and in 11 active regions using 1K resolution (SN: 151) SDO/HMI images.
Region 13563 [S07W20] was quiet and stable.
Region 13565 [N05E38] lost the magnetic
delta structure and produced a few low level C flares. C1 flares: C1.2 @
09:55 UT
New region 13566 [S12W61] emerged on January 27 and was numbered by
SWPC 3 days later.
New region 13567 [N19E60] rotated into view on January 28 with SWPC
numbering the region 2 days later. A major flare is possible. C1 flares:
C1.0 @ 05:07, C1.0 @ 20:53, C1.6 @ 23:07 UT
New region 13568 [S09W36] emerged on January 27 and was numbered by
SWPC 3 days later.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9366 [N19E16] was mostly quiet and stable. C1 flares: C1.4 @ 06:25
UT
S9371 [S09E22] was quiet and stable.
S9382 [S12E03] was quiet and stable.
New region S9385 [N18W23] emerged before noon, then decayed slowly.
New region S9386 [N05W23] emerged before noon and decayed
slowly during the latter half of the day.
New region S9387 [N11W13] emerged with tiny spots.
New region S9388 [S03E77] rotated into view with tiny spots.
AR 13559 produced C1 flares from behind the northwest
limb: C1.4 @ 02:56, C1.3 @ 05:55, C1.3 @ 14:50, C1.3 @ 15:11, C1.7 @ 16:02,
C1.4 @ 17:22, C1.3 @ 18:37, C1.6 @ 18:59 UT
AR S9346 was the source of a C1.9 flare at 00:16 UT.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.1 | 00:49 | S9346 | GOES16 | simultaneous flare behind the southeast limb | |
| C2.0 | 06:41 | 13565 | GOES16 | ||
| C5.7 | 17:39 | 13559 | GOES16 |
January 28, 30: No obviously Earth directed CMEs were observed.
January 29: A partial halo CME was observed after the M6.8 flare in
AR 13559 early in the day. While Earth is not in the path of the major part
of the ejecta, there is a chance of a shock arrival on January 31.
[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) was Earth facing on January 26-28. A positive polarity southern hemisphere coronal hole (CH1201) could become Earth facing on February 1-2. CH1201 is probably too far south to cause a geomagnetic disturbance.
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 active on January 31-February 1 due to a possible shock arrival associated with the M6 flare in AR 13559 on January 29. A quiet geomagnetic field is likely on February 2.
| 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 | ||||||||||
| S9346 | 2024.01.19 | N28W76 |
 |
||||||||
| S9364 | 2024.01.24 | S10W45 | |||||||||
| S9366 | 2024.01.25 | 4 | 2 | N19E16 | 0010 | BXO |
 |
 |
|||
| S9367 | 2024.01.25 | N31W17 | |||||||||
| S9368 | 2024.01.25 | S26W37 | |||||||||
| 13563 | 2024.01.26 2024.01.26 |
3 | 1 | S05W25 | 0008 | BXO |
 |
 |
location: S07W20 | ||
| S9369 | 2024.01.26 | N24W52 | |||||||||
| S9370 | 2024.01.26 | N15W12 | |||||||||
| S9371 | 2024.01.26 | 7 | 1 | S09E22 | 0015 | BXO |
 |
 |
|||
| S9374 | 2024.01.26 | N07W50 | |||||||||
| S9375 | 2024.01.26 | S21W12 | |||||||||
| 13568 | 2024.01.27 2024.01.30 |
2 | 7 | 5 | S09W38 | 0010 | BXO | CRO |
 |
 |
area: 0025 location: S09W36 |
| 13566 | 2024.01.27 2024.01.30 |
2 | 5 | 3 | S13W61 | 0010 | BXO | DRO |
 |
 |
area: 0060 |
| S9379 | 2024.01.27 | N31W18 | |||||||||
| 13565 | 2024.01.27 2024.01.28 |
5 | 17 | 11 | N07E36 | 0050 | DAO | DRI |
 |
 |
beta-gamma location: N05E38 |
| 13564 | 2024.01.28 | S09E27 | |||||||||
| 13567 | 2024.01.28 2024.01.30 |
4 | 23 | 12 | N20E70 | 0210 | DSO | DKI |
 |
 |
beta-gamma location: N19E60 area: 0440 |
| S9382 | 2024.01.28 | 5 | 3 | S12E03 | 0040 | DRO |
 |
 |
|||
| S9383 | 2024.01.29 | S17W31 |
 |
||||||||
| S9384 | 2024.01.29 | S35E03 |
 |
||||||||
| S9385 | 2024.01.30 | 2 | 1 | N18W23 | 0005 | AXX |
 |
||||
| S9386 | 2024.01.30 | 1 | N05W23 | 0003 | AXX |
 |
|||||
| S9387 | 2024.01.30 | 2 | 1 | N11W13 | 0008 | BXO |
 |
||||
| S9388 | 2024.01.30 | 2 | 1 | S03E77 | 0010 | BXO |
 |
||||
| Total spot count: | 13 | 78 | 41 | ||||||||
| Sunspot number: | 53 | 198 | 151 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 23 | 100 | 63 | (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): | 58 | 109 | 121 | ||||||||
| 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 | 165.5 (1) | 119.4 (2A) / 123.3 (2B) / 161.4 (2C) | (117.9 projected, -3.3) | (5.6) | |
| 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.
