The geomagnetic field was at quiet to major storm levels on February 28 due to CME effects. Solar wind speed at SOHO ranged between 561 and 826 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.
Solar flux density measured at 20h UT on 2.8 GHz was 160.9 - increasing 27.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 135.17). The Potsdam WDC planetary A index was 27 (STAR Ap - based on the mean of three hour interval ap indices: 26.6). Three hour interval K indices: 65332144 (planetary), ******** (Boulder), 56332256 (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 11 active regions using 2K resolution (SN: 214) and in 8 active regions using 1K resolution (SN: 125) SDO/HMI images.
Region 13230 [S22W58] decayed slowly and was
mostly quiet.
Region 13234 [N23W38] is still a complex region with multiple
magnetic deltas. Some decay was observed in the easternmost spot section. Another
major flare is possible.
Region 13236 [S27W44] decayed further and was
quiet.
Region 13238 [N09E51] was quiet and stable.
New region 13239 [N32E69] rotated into view on February 27 and was
numbered the next day by SWPC. C1 flare: C1.6 @ 12:05 UT
Spotted regions not observed (or interpreted
differently) by SWPC:
S8310 [S26E05] was quiet and stable.
S8311 [S20E21] was quiet and stable.
S8316 [N19W05] was quiet and stable.
New region S8319 [N28E85] rotated partly into
view and might be capable of M class flaring.
New region S8320 [S15E67] emerged with a tiny spot. This region has
produced several flares early on March 1.
New region S8321 [N41E29] emerged with a tiny spot at a high
latitude location.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.2 | 00:25 | 13230 | GOES16 | ||
| C2.4 | 04:12 | 13230 | GOES16 | ||
| C2.4 | 05:06 | S8319 | GOES18 | ||
| C2.4 | 05:33 | 13234 | GOES16 | ||
| C2.5 | 06:28 | 13234 | GOES16 | ||
| C3.3 | 06:59 | 13234 | GOES18 | ||
| C2.0 | 08:44 | 13234 | GOES16 | ||
| C2.0 | 14:16 | 13234 | GOES16 | ||
| C2.1 | 14:40 | 13235 | GOES16 | ||
| C5.8 | 16:22 | N26W31 | 13234 | GOES16 | |
| M8.6 | 17:50 | 13234 | GOES16 | ||
| C2.4 | 20:55 | 13234 | GOES16 | ||
| C4.3 | 22:34 | 13234 | GOES16 | ||
| C2.8 | 23:35 | 13234 | GOES16 |
February 26-28: No obviously Earth directed CMEs were observed.
[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) was Earth facing on February 24-25. Due to the strong
solar storms overtaking the associated high speed stream, it will not be
possible to observe any disturbance during this solar rotation.
A trans equatorial coronal hole (CH1133) will likely rotate
across the central meridian on March 1-2.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is very poor. Propagation on long distance northeast-southwest paths is poor.
Quiet to active conditions are likely on March 1 due to lingering CME effects. March 2-3 could see quiet to unsettled conditions. Effects from CH1133 could cause unsettled to minor storm conditions on March 4-5.
| 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 |
N26W88 |
 |
||||||||
| 13230 | 2023.02.17 2023.02.18 |
2 | 7 | 2 | S23W58 | 0010 | AXX | BXO |
 |
 |
location: S22W58 |
| 13234 | 2023.02.20 2023.02.20 |
25 | 51 | 26 | N25W36 | 0860 | FKC | EKC |
 |
 |
beta-gamma-delta location: N23W38 |
| S8301 | 2023.02.21 | S12W41 | |||||||||
| 13235 | 2023.02.22 2023.02.23 |
N19W59 |
 |
||||||||
| 13236 | 2023.02.23 2023.02.23 |
9 | 22 | 9 | S27W44 | 0080 | CSO | CRO |
 |
 |
area: 0060 |
| 13237 | 2023.02.23 2023.02.24 |
2 | S08W25 | 0000 | AXX |
 |
real location: S13W30 SWPC observers were confused by the spots of AR S8315 on February 27 and changed the location to that group |
||||
| S8306 | 2023.02.23 | N12W17 | |||||||||
| S8307 | 2023.02.24 | N13W47 | |||||||||
| S8308 | 2023.02.24 | S22W19 |
 |
||||||||
| S8309 | 2023.02.25 | N13W15 | |||||||||
| S8310 | 2023.02.25 | 3 | S26E05 | 0004 | BXO |
 |
 |
||||
| S8311 | 2023.02.25 | 9 | 2 | S20E21 | 0020 | BXO |
 |
 |
|||
| S8313 | 2023.02.25 | N18W04 | |||||||||
| 13238 | 2023.02.26 2023.02.27 |
1 | 5 | 3 | N09E50 | 0070 | HSX | CSO |
 |
 |
location: N09E51 area: 0150 |
| S8315 | 2023.02.26 | S08W25 |
 |
||||||||
| S8316 | 2023.02.27 | 2 | N18W05 | 0003 | BXO |
 |
 |
||||
| 13239 | 2023.02.27 2023.02.28 |
1 | 2 | 1 | N30E69 | 0090 | HSX | HSX |
 |
 |
location: N32E69 area: 0160 |
| S8318 | 2023.02.27 | S29E23 |
 |
||||||||
| S8319 | 2023.02.28 | 1 | 1 | N28E85 | 0100 | HSX |
 |
||||
| S8320 | 2023.02.28 | 1 | 1 | S15E67 | 0005 | AXX |
 |
||||
| S8321 | 2023.02.28 | 1 | N41E29 | 0002 | AXX |
 |
|||||
| Total spot count: | 40 | 104 | 45 | ||||||||
| Sunspot number: | 100 | 214 | 125 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 65 | 132 | 73 | (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): | 110 | 118 | 100 | ||||||||
| 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 |
| 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 | 92.3 (+5.8) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | (97.0 projected, +4.7) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.4 | (100.2 projected, +3.2) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 77.6 | (103.0 projected, +2.8) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 113.1 | (107.8 projected, +4.8) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (113.8 projected, +6.0) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 110.9 | (118.9 projected, +5.1) | 14.6 |
| 2023.03 | (1) | (2A/2B) / 150.0 (2C) | (122.0 projected, +3.1) | () | |
| 2023.04 | (127.4 projected, +5.4) | ||||
| 2023.05 | (133.2 projected, +5.8) | ||||
| 2023.06 | (136.4 projected, +3.2) | ||||
| 2023.07 | (135.9 projected, -0.5) | ||||
| 2023.08 | (136.9 projected, +1.0) | ||||
| 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.
