The geomagnetic field was quiet to unsettled on March 1. Solar wind speed at SOHO ranged between 531 and 755 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.
Solar flux density measured at 20h UT on 2.8 GHz was 162.0 - increasing 27.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 135.34). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 31131122 (planetary), ******** (Boulder), 21021112 (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 14 active regions using 2K resolution (SN: 217) and in 9 active regions using 1K resolution (SN: 125) SDO/HMI images.
Region 13230 [S22W69] decayed slowly and was quietly.
Region 13234 [N23W53] decayed in the trailing
spot section. A major flare is possible as there are still multiple magnetic
deltas. C1 flares: C1.8 @ 12:13, C1.8 @ 15:31, C1.8 @ 20:25 UT
Region 13236 [S26W58] decayed slowly and was
mostly quiet.
Region 13238 [N09E38] was quiet and stable.
Region 13239 [N32E56] was quiet and stable.
New region 13240 [S14E54] emerged on February 28 and was numbered the
next day by SWPC. The region was unstable early in the day.
New region 13241 [N28E70] rotated into view on February 28 and
received its NOAA number the following day.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8308 [S28W27] reemerged with tiny spots.
S8311 [S20E05] was quiet and stable.
S8315 [S08W39] reemerged with a tiny spot.
New region S8322 [S13W22] emerged before noon, then decayed slowly.
New region S8323 [N11E81] rotated into view
with mature spots.
New region S8324 [N18W09] emerged with a tiny spot.
New region S8325 [N17E11] emerged with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.1 | 00:32 | 13240 | GOES16 | ||
| M1.0/1N | 01:07 | 13234 | GOES16 | simultaneous, smaller flare in AR 13240 | |
| C5.4 | 01:40 | 13234 | GOES16 | ||
| C9.3 | 01:47 | S15E69 | 13240 | GOES16 | |
| C5.1 | 03:20 | 13234 | GOES16 | ||
| C3.1 | 04:04 | N24W33 | 13234 | GOES16 | |
| C6.3 | 04:19 | S15E69 | 13240 | GOES16 | |
| C2.4 | 06:16 | 13234 | GOES16 | ||
| C3.0 | 06:30 | 13234 | GOES16 | ||
| C4.3 | 06:49 | 13234 | GOES16 | ||
| C2.3 | 07:35 | 13234 | GOES16 | ||
| C3.0 | 09:10 | N22W39 | 13234 | GOES16 | |
| C2.3 | 11:42 | 13234 | GOES16 | ||
| C4.2 | 13:58 | 13236 | GOES16 | ||
| C2.0 | 19:36 | 13236 | GOES16 | ||
| C2.7 | 23:22 | 13234 | GOES16 |
February 27 - March 1: 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 trans equatorial coronal hole (CH1133) will 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 poor. Propagation on long distance northeast-southwest paths is poor.
Quiet to unsettled conditions are likely on March 2-3. 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 | ||||||||||
| 13230 | 2023.02.17 2023.02.18 |
2 | 3 | S23W72 | 0000 | AXX | BXO |
 |
 |
location: S22W69 area: 0006 |
|
| 13234 | 2023.02.20 2023.02.20 |
20 | 31 | 17 | N25W49 | 0850 | FKC | EKC |
 |
 |
beta-gamma-delta location: N23W53 area: 0740 |
| S8301 | 2023.02.21 | S12W54 | |||||||||
| 13235 | 2023.02.22 2023.02.23 |
N19W73 | |||||||||
| 13236 | 2023.02.23 2023.02.23 |
5 | 15 | 7 | S27W58 | 0030 | CSO | CRO |
 |
 |
location: S26W58 |
| 13237 | 2023.02.23 2023.02.24 |
S08W38 |
real location: S13W43 SWPC observers were confused by the spots of AR S8315 on February 27 and changed the location to that group |
||||||||
| S8306 | 2023.02.23 | N12W30 | |||||||||
| S8308 | 2023.02.24 | 4 | S22W32 | 0007 | BXO |
 |
|||||
| S8309 | 2023.02.25 | N13W28 | |||||||||
| S8310 | 2023.02.25 | S26W08 |
 |
||||||||
| S8311 | 2023.02.25 | 6 | 1 | S20E05 | 0015 | BXO |
 |
 |
|||
| S8313 | 2023.02.25 | N18W17 | |||||||||
| 13238 | 2023.02.26 2023.02.27 |
1 | 3 | 1 | N09E36 | 0070 | HSX | HSX |
 |
 |
location: N09E38 area: 0140 |
| S8315 | 2023.02.26 | 1 | S08W38 | 0001 | AXX |
 |
|||||
| S8316 | 2023.02.27 | N18W18 |
 |
||||||||
| 13239 | 2023.02.27 2023.02.28 |
1 | 2 | 1 | N30E55 | 0100 | HSX | HSX |
 |
 |
location: N32E56 area: 0220 |
| S8318 | 2023.02.27 | S29E10 | |||||||||
| 13241 | 2023.02.28 2023.03.01 |
3 | 2 | 2 | N27E73 | 0050 | HSX | HAX |
 |
 |
area: 0080 location: N28E70 |
| 13240 | 2023.02.28 2023.03.01 |
3 | 4 | 3 | S16E55 | 0010 | BXO |
 |
 |
area: 0015 location: S14E54 |
|
| S8321 | 2023.02.28 | N41E16 |
 |
||||||||
| S8322 | 2023.03.01 | 2 | S13W22 | 0002 | BXO |
 |
|||||
| S8323 | 2023.03.01 | 2 | 2 | N11E81 | 0240 | HAX |
 |
||||
| S8324 | 2023.03.01 | 1 | 1 | N18W09 | 0003 | AXX |
 |
||||
| S8325 | 2023.03.01 | 1 | N17E11 | 0002 | AXX |
 |
|||||
| Total spot count: | 35 | 77 | 35 | ||||||||
| Sunspot number: | 105 | 217 | 125 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 65 | 110 | 68 | (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): | 116 | 119 | 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 | 162.0 (1) | 3.4 (2A) / 105 (2B) / 149.6 (2C) | (122.0 projected, +3.1) | (8.0) | |
| 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.
