The geomagnetic field was quiet to unsettled on February 6, weakly under the influence of effects from CH1201. Solar wind speed at SOHO ranged between 449 and 571 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at 0.3 pfu, just above background levels, at the end of the day.
Solar flux density measured at 18h UT on 2.8 GHz was 179.0 - decreasing 7.0 over the previous solar rotation (The measurement at 20h UT was flare enhanced from a long duration M1 event that peaked at 18:49 UT). (Centered 1 year average SF at 1 AU - 183 days ago: 157.33. 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 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.9). Three hour interval K indices: 32122121 (planetary), 21222221 (Boulder), 52111230 (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 19 active regions using 2K resolution (SN: 364) and in 17 active regions using 1K resolution (SN: 250) SDO/HMI images.
Region 13565 [N05W55] decayed slowly and
quietly.
Region 13567 [N20W39] decayed slowly and quietly.
Region 13570 [S04W18] was quiet and stable.
Region 13571 [S17W03] decayed slowly and
quietly.
Region 13572 [S12W47] developed slowly and was quiet.
Region 13573 [N21W59] decayed slowly and quietly.
Region 13574 [N16E08] decayed slowly and quietly. The region has reversed
polarities.
Region 13575 [S37W73] decayed in the leading spot section. This is still a compact and
complex spot group with a strong magnetic delta in the trailing spot section. The region has reversed
polarities and could produce M and possibly X flares. A major M5.1 long
duration event peaked at 03:33 UT on February 7. C1 flares: C1.9 @ 23:47 UT
Region 13576 [S15E43] was less active than on previous days as the
magnetic delta structure weakened. A major flare is possible.
Region 13577 [N24E08] decayed slowly and quietly.
Region 13578 [S05E54] developed slowly and was mostly quiet. The region has reversed polarities.
Minor polarity intermixing developed in the southern part of the spot group.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9394 [N22W64] was quiet and stable.
S9400 [N13W53] reemerged with tiny spots.
S9401 [S22E09] was quiet and stable.
S9404 [S13W62] developed slowly and quietly.
S9405 [N39E46] was quiet and stable.
New region S9406 [N12E71] rotated into view with tiny spots.
New region S9407 [S13W43] emerged with tiny spots.
New region S9408 [S10E62] emerged with tiny spots.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.2 | 00:40 | 13570? | GOES16 | ||
| M2.2 | 02:28 | 13575 | GOES16 | ||
| M4.2 | 03:11 | 13575 | GOES16 | LDE, minor proton enhancement moderate type II and IV radio sweep |
|
| M1.0 | 05:03 | 13576 | GOES16 | ||
| C6.8 | 06:06 | 13576 | GOES16 | simultaneous flare in AR S9404 | |
| C6.4 | 06:56 | GOES16 | |||
| C3.8 | 09:05 | 13576 | GOES16 | ||
| C4.2 | 09:33 | 13576 | GOES16 | ||
| C2.8 | 10:43 | 13576 | GOES16 | ||
| C2.6 | 11:26 | 13576 | GOES16 | ||
| C4.5 | 11:45 | 13576 | GOES16 | ||
| C4.1 | 12:14 | 13576 | GOES16 | ||
| C9.4 | 12:58 | 13575 | GOES16 | ||
| C3.1 | 13:47 | 13576 | GOES16 | ||
| C2.5 | 14:04 | 13576 | GOES16 | ||
| C2.6 | 15:32 | 13576 | GOES16 | ||
| C3.9 | 16:08 | 13578 | GOES16 | ||
| C5.1 | 16:14 | 13576 | GOES16 | ||
| C3.0 | 16:51 | 13576 | GOES16 | ||
| C3.2 | 17:44 | 13575 | GOES16 | ||
| C2.6 | 18:15 | 13575 | GOES16 | ||
| C6.2 | 18:35 | 13575 | GOES16 | ||
| M1.3 | 18:49 | 13575 | GOES16 | LDE, flare still bright in EUV at 20:35 UT | |
| C7.4 | 19:27 | 13575 | GOES16 | different flare center than M1.3 flare | |
| C2.5 | 21:47 | 13575 | GOES16 | ||
| C2.7 | 21:56 | 13576 | GOES16 | ||
| C2.3 | 22:12 | 13578 | GOES16 | ||
| C2.0 | 22:32 | 13575 | GOES16 |
February 3-5: No obviously Earth directed CMEs were observed.
February 6: A partial halo CME was observed after an M2.2 flare and a long duration M4.2 event peaking at 03:11 UT in AR 13575. A shock wave affected the corona far from the source. A
partial halo CME was associated with this event. The CME was visible in
LASCO C2 imagery from 02:36 UT. While the bulk of the CME is not headed for
Earth, there is a chance of a weak solar wind shock on February 8 or 9. A
nearly symmetrical full halo CME was observed near noon. While there was a
large filament eruption in the northern hemisphere that was suspected as the
origin, any CME associated with that event would be unlikely to cause a CME
with the observed mass distribution and intensity. The source of the CME is
thus likely to have been backsided.
[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]
No obvious coronal holes are currently in or near Earth facing positions.
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 February 7 and most of February 8. During the latter half of February 8 or on February 9 there is a chance of weak CME effects associated with long duration events in AR 13575 early on February 6.
| 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 | ||||||||||
| 13565 | 2024.01.27 2024.01.28 |
4 | 5 | 3 | N06W43 | 0010 | BXO | DRI |
 |
 |
area: 0040 location: N05W42 |
| 13564 | 2024.01.28 | 3 | S13W72 | 0030 | CAO | SWPC has apparently included the spots of AR S9404 in this region, despite AR S9404 being 10 degrees further east. | |||||
| 13567 | 2024.01.28 2024.01.30 |
5 | 1 | N17W35 | 0010 | AXX |
 |
 |
location: N20W29 |
||
| 13570 | 2024.01.30 2024.02.01 |
2 | S05W20 | 0003 | BXO |
 |
 |
location: S04W18 |
|||
| 13572 | 2024.01.31 2024.02.01 |
2 | 6 | 3 | S12W48 | 0010 | BXO | DRO |
 |
 |
location: S12W47 area: 0025 |
| 13571 | 2024.01.31 2024.02.01 |
5 | 10 | 4 | S17W05 | 0110 | HSX | CAO |
 |
 |
area: 0160 location: S17W03 |
| 13575 | 2024.01.31 2024.02.02 |
7 | 9 | 4 | S36W78 | 0250 | DKI | DKC |
 |
 |
beta-gamma-delta reversed polarities location: S37W73 area: 0290 |
| 13573 | 2024.02.01 2024.02.01 |
2 | 1 | 1 | N21W61 | 0010 | BXO | AXX |
 |
 |
location: N21W59 area: 0003 |
| 13574 | 2024.02.01 2024.02.01 |
3 | 5 | 3 | N17E03 | 0030 | CSO | CRO |
 |
 |
area: 0040 location: N16E08 reversed polarities |
| S9394 | 2024.02.01 | 3 | 2 | N22W64 | 0008 | BXO |
 |
 |
|||
| S9395 | 2024.02.01 | N26W45 | |||||||||
| 13577 | 2024.02.02 2024.02.05 |
4 | 11 | 4 | N24E06 | 0010 | BXO | DRO |
 |
 |
area: 0025 location: N24E08 |
| 13576 | 2024.02.03 2024.02.03 |
41 | 72 | 40 | S16E46 | 0540 | FKI | FKC |
 |
 |
beta-gamma-delta area: 0930 location: S15E43 |
| S9400 | 2024.02.03 | 2 | 1 | N13W53 | 0005 | AXX |
 |
||||
| S9401 | 2024.02.04 | 7 | S22E09 | 0011 | BXO |
 |
 |
||||
| 13578 | 2024.02.04 2024.02.05 |
3 | 14 | 5 | S05E53 | 0020 | CRO | CRO |
 |
 |
beta-gamma location: S05E54 area: 0035 reversed polarities |
| S9403 | 2024.02.04 | S07W09 | |||||||||
| S9404 | 2024.02.05 | 10 | 4 | S13W62 | 0120 | CAO |
 |
 |
|||
| S9405 | 2024.02.05 | 2 | 1 | N39E46 | 0004 | BXO |
 |
 |
|||
| S9406 | 2024.02.06 | 2 | 1 | N12E71 | 0005 | AXX |
 |
||||
| S9407 | 2024.02.06 | 4 | 2 | S17W43 | 0020 | CRO |
 |
||||
| S9408 | 2024.02.06 | 4 | 1 | S10E62 | 0010 | CRO |
 |
||||
| Total spot count: | 74 | 174 | 80 | ||||||||
| Sunspot number: | 152 | 364 | 250 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 72 | 225 | 131 | (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): | 167 | 200 | 200 | ||||||||
| 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 |
| 2022.06 | 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 | 121.1 (+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 | 124.1 (+1.2) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.2 (+1.1) (SC25 solar max candidate) |
8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | 124.3 (-0.9) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | (123.4 projected, -0.9) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | (123.1 projected, -0.3) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | (123.9 projected, +0.8) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | (123.9 projected, +0.0) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | (120.5 projected, -3.4) | 9.60 |
| 2024.01 | 164.6 | 159.3 | 123.0 | (117.1 projected, -3.3) | 5.46 |
| 2024.02 | 159.8 (1) | 29.0 (2A) / 140.3 (2B) / 166.6 (2C) | (116.3 projected, -0.8) | (4.3) | |
| 2024.03 | (115.8 projected, -0.5) | ||||
| 2024.04 | (115.7 projected, -0.1) | ||||
| 2024.05 | (117.0 projected, +1.3) | ||||
| 2024.06 | (116.2 projected, -0.8) | ||||
| 2024.07 | (114.5 projected, -1.7) | ||||
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.
