The geomagnetic field was quiet to unsettled on February 24. Solar wind speed at SOHO ranged between 371 and 685 km/sec. The high latitude magnetometer at Andenes recorded quiet levels.
Solar flux density measured at 20h UT on 2.8 GHz was 164.1 - increasing 26.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 134.51). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8). Three hour interval K indices: 31212000 (planetary), ******** (Boulder), 22222000 (Andenes).
The background x-ray flux was at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 255) and in 7 active regions using 1K resolution (SN: 172) SDO/HMI images.
Region 13229 [N26W35] developed after noon as
new negative polarity flux emerged just northwest of the leading positive
polarity spots. This development may have contributed to destabilizing a
nearby filament and subsequently the long duration M3 flare later in the
day. C1 flares: C1.5 @ 18:09 UT
Region 13230 [S22W06] became slightly more complex as new positive
polarity flux emerged to the immediate south of the leader spots. C1 flares:
C1.9 @ 11:28, C1.4 @ 14:52 UT
Region 13234 [N24E17] developed further and still has a magnetic
delta. A major flare is possible.
Region 13235 [N19W03] lost a little area and still has a magnetic delta.
Further minor M class flares are possible. C1 flares: C1.8 @ 00:30, C1.5 @
02:06, C1.7 @ 02:59 UT
Region 13236 [S27E08] developed further and gained a magnetic delta
structure in a central northern penumbra. M class flares are possible. C1
flares: C1.7 @ 13:54 UT
New region 13237 [S12E24] emerged on February 23 and was numbered the
following day by SWPC.
Spotted regions not observed (or interpreted
differently) by SWPC:
New region S8307 [N12E05] emerged with a few spots.
New region S8308 [S22E32] was observed with tiny spots in an
old plage area.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.0 | 00:48 | 13236 | GOES16 | ||
| C8.7/1F | 06:12 | S24E07 | 13230 | GOES16 | |
| C6.8 | 07:09 | 13235 | GOES16 | ||
| C2.1 | 09:41 | N23E38 | 13234 | GOES16 | |
| C2.9 | 13:09 | S27E14 | 13236 | GOES16 | |
| M1.2 | 17:15 | 13235 | GOES16 | ||
| M3.7/2B | 20:30 | 13229 | GOES16 | moderate type IV radio sweep LDE, fast full halo CME. Probably triggered by nearby filament eruption. Proton flux enhancement |
|
| C8.9 | 23:00 | 13235 | GOES16 |
February 22-23: No obviously Earth directed CMEs were observed.
February 24: A fast asymmetric full halo CME was observed after the
M3 flare in AR 13229. The CME could reach Earth sometime between late on
February 26 and noon on February 27.
[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 recurrent trans equatorial coronal hole (CH1132) will be Earth facing on February 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.
Quiet to unsettled geomagnetic conditions are likely on February 25-26. The February 24 CME could reach Earth between late on February 26 and noon on February 27 and cause unsettled to major storm conditions. On February 27-28 effects from CH1132 could contribute further to the disturbed geomagnetic field.
| Coronal holes (1) | Coronal mass ejection (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 | ||||||||||
| 13229 | 2023.02.16 2023.02.16 |
12 | 28 | 14 | N25W32 | 0150 | ESO | EAI |
 |
 |
beta-gamma |
| S8286 | 2023.02.17 | S10W37 |
 |
||||||||
| 13230 | 2023.02.17 2023.02.18 |
11 | 17 | 10 | S22W08 | 0120 | CSO | DAO |
 |
 |
|
| 13233 | 2023.02.18 2023.02.20 |
N14W56 |
 |
location: N18W45 | |||||||
| S8295 | 2023.02.19 | S23W38 |
 |
||||||||
| S8298 | 2023.02.20 | N14W07 | |||||||||
| 13234 | 2023.02.20 2023.02.20 |
25 | 56 | 33 | N25E19 | 0580 | EKC | FKC |
 |
 |
beta-gamma-delta area: 0910 location: N24E17 |
| S8301 | 2023.02.21 | S12E11 | |||||||||
| 13235 | 2023.02.22 2023.02.23 |
6 | 25 | 13 | N19W06 | 0040 | DAO | DRI |
 |
 |
beta-delta location: N19W03 area: 0070 |
| S8303 | 2023.02.22 | S25W24 |
 |
|
|||||||
| 13236 | 2023.02.23 2023.02.23 |
14 | 35 | 25 | S28E05 | 0080 | DAI | DAC |
 |
 |
beta-delta location: S27E08 area: 0300
|
| 13237 | 2023.02.23 2023.02.24 |
2 | 4 | 3 | S12E23 | 0010 | BXO | DRO |
 |
 |
area: 0030 |
| S8306 | 2023.02.23 | N12E35 |
 |
||||||||
| S8307 | 2023.02.24 | 5 | 4 | N12E05 | 0020 | CRO |
 |
||||
| S8308 | 2023.02.24 | 5 | S22E32 | 0008 | BXO |
 |
|||||
| Total spot count: | 70 | 175 | 102 | ||||||||
| Sunspot number: | 130 | 255 | 172 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 100 | 209 | 136 | (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): | 143 | 140 | 138 | ||||||||
| 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 (solar max) | 7.88 |
| 2017.09 | 91.3 | 92.3 | 43.6 | 18.2 (-1.3) | 18.22 (cycle 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 |
| 2021.07 | 81.0 | 83.6 | 34.3 | 31.4 (+3.8) | 5.51 |
| 2021.08 | 77.7 | 79.7 | 22.0 | 35.4 (+4.0) | 6.19 |
| 2021.09 | 87.0 | 88.2 | 51.3 | 40.2 (+4.8) | 6.33 |
| 2021.10 | 88.9 | 88.3 | 37.4 | 45.2 (+5.0) | 7.38 |
| 2021.11 | 86.2 | 84.4 | 34.8 | 50.8 (+5.6) | 9.83 |
| 2021.12 | 103.0 | 99.8 | 67.5 | 55.9 (+5.1) | 6.40 |
| 2022.01 | 103.8 | 100.5 | 55.3 | 60.1 (+4.2) | 8.92 |
| 2022.02 | 109.1 | 106.5 | 60.9 | 64.7 (+4.6) | 10.46 |
| 2022.03 | 117.0 | 115.8 | 78.6 | 68.7 (+4.0) | 10.20 |
| 2022.04 | 130.8 | 131.7 | 84.0 | 73.0 (+4.3) | 11.79 |
| 2022.05 | 133.8 | 136.8 | 96.5 | 77.2 (+4.2) | 7.48 |
| 2022.06 | 116.1 | 119.8 | 70.3 | 80.9 (+3.7) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | 86.5 (+5.6) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 74.6 | (92.4 projected, +5.9) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | (97.4 projected, +5.0) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.4 | (100.5 projected, +3.1) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 77.6 | (103.4 projected, +2.9) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 113.1 | (108.2 projected, +4.8) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (114.2 projected, +6.0) | 8.73 |
| 2023.02 | 168.7 (1) | 107.8 (2A) / 125.8 (2B) / 145.9 (2C) | (119.2 projected, +5.0) | (10.7) | |
| 2023.03 | (122.3 projected, +3.1) | ||||
| 2023.04 | (127.7 projected, +5.4) | ||||
| 2023.05 | (133.5 projected, +5.8) | ||||
| 2023.06 | (136.8 projected, +3.3) | ||||
| 2023.07 | (136.3 projected, -0.5) | ||||
| 2023.11 | (142.5 projected max SC25) | ||||
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: SIDC-SILSO.
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.
