The geomagnetic field was quiet to unsettled on March 11. Solar wind speed at SOHO ranged between 320 and 386 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 157.4 - decreasing 42.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 136.93). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.5). Three hour interval K indices: 32101023 (planetary), 12101222 (Boulder), 53111126 (Andenes).
The background x-ray flux was at the class B7 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 16 active regions using 2K resolution (SN: 267) and in 13 active regions using 1K resolution (SN: 176) SDO/HMI images.
Region 13239 [N33W72] was quiet and stable.
Region 13240 [S17W79] was quiet and stable.
Region 13241 [N29W59] was quiet and stable.
Region 13242 [N11W61] decayed slowly and quietly.
Region 13245 [S22W29] decayed slowly and produced a few C flares. C1
flares: C1.4 @ 05:35, C1.3 @ 06:10, C1.2 @ 10:16, C1.2 @ 10:38, C1.6 @ 15:01
UT
Region 13246 [N24W12] decayed slowly and quietly.
Region 13247 [S24E03] was quiet and stable.
Region 13249 [S12E23] developed slowly and quietly.
Region 13250 [S19E19] was mostly quiet and stable.
Region 13251 [S13E44] was quiet and stable.
Region 13252 [N13E46] was quiet and stable.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8348 [N23E33] decayed slowly after noon.
New region S8357 [S30E14] emerged with several spots.
New region S8358 [S03W49] emerged with tiny spots.
New region S8359 [N15E01] emerged with tiny spots.
New region S8360 [N19E68] rotated into view with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.9 | 01:03 | S25W17 | 13245 | GOES16 | |
| C2.0 | 14:39 | 13245 | GOES16 |
March 9, 11: No obviously Earth directed CMEs were observed.
March 10: A partial halo CME was observed after a large filament
eruption in the southwestern and northwestern quadrants. The CME could reach
Earth after noon on March 13 and cause unsettled to minor storm conditions.
[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 (CH1134) will be in an Earth facing position on March 11-12.
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 is likely on March 12-13. The March 10 CME could reach Earth on March or 14 and cause unsettled to minor storm conditions. Unsettled and active intervals are possible on March 14-15 due to effects from CH1134.
| 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 | ||||||||||
| 13239 | 2023.02.27 2023.02.28 |
1 | 1 | 1 | N32W70 | 0070 | HSX | HSX |
 |
 |
location: N33W72 area: 0100 |
| 13241 | 2023.02.28 2023.03.01 |
1 | 2 | 1 | N28W61 | 0030 | HSX | HRX |
 |
 |
location: N29W59 area: 0030 |
| 13240 | 2023.02.28 2023.03.01 |
1 | S17W79 | 0002 | AXX |
 |
 |
SWPC on March 6 moved the location to near AR S8327 |
|||
| 13242 | 2023.03.01 2023.03.02 |
1 | 8 | 1 | N10W57 | 0100 | HSX | CSO |
 |
 |
location: N11W61 area: 0200 |
| 13245 | 2023.03.02 2023.03.03 |
7 | 22 | 9 | S23W31 | 0220 | CSO | DHO |
 |
 |
area: 0290 location: S22W29 |
| S8330 | 2023.03.03 | S17W40 | |||||||||
| 13246 | 2023.03.04 2023.03.05 |
2 | 3 | 3 | N24W13 | 0030 | HSX | HAX |
 |
 |
location: N24W12 area: 0050 |
| S8335 | 2023.03.04 | N22W54 | |||||||||
| S8336 | 2023.03.04 | S08W46 | |||||||||
| 13247 | 2023.03.05 2023.03.06 |
4 | 15 | 4 | S23E03 | 0070 | CSO | CSO |
 |
 |
location: S24E03 area: 0080 |
| S8343 | 2023.03.06 | S12W30 | |||||||||
| 13249 | 2023.03.07 2023.03.07 |
1 | 10 | 4 | S11E21 | 0060 | HSX | CAO |
 |
 |
location: S12E23 area: 0070 |
| S8346 | 2023.03.07 | N33E10 | |||||||||
| S8348 | 2023.03.08 | 6 | 2 | N23E33 | 0010 | BXO |
 |
 |
|||
| 13251 | 2023.03.08 2023.03.09 |
1 | 6 | 1 | S13E42 | 0050 | HSX | CAO |
 |
 |
area: 0100 location: S13E44 |
| S8350 | 2023.03.08 | N13W16 | |||||||||
| 13252 | 2023.03.09 2023.03.10 |
1 | 1 | 1 | N13E47 | 0020 | HSX | HSX |
 |
 |
location: N12E46 area: 0040 |
| 13250 | 2023.03.09 2023.03.09 |
7 | 18 | 14 | S20E19 | 0070 | CAO | DRI |
 |
 |
location: S19E19 area: 0110 |
| S8353 | 2023.03.09 | S29W47 | |||||||||
| S8354 | 2023.03.10 | S15W20 |
 |
||||||||
| S8355 | 2023.03.10 | N12E12 |
 |
||||||||
| S8356 | 2023.03.10 | S28E30 |
 |
||||||||
| S8357 | 2023.03.11 | 9 | 4 | S30E14 | 0025 | CRO |
 |
||||
| S8358 | 2023.03.11 | 2 | S03W49 | 0002 | BXO |
 |
|||||
| S8359 | 2023.03.11 | 2 | N15E01 | 0002 | AXX |
 |
|||||
| S8360 | 2023.03.11 | 1 | 1 | N19E68 | 0002 | AXX |
 |
||||
| Total spot count: | 26 | 107 | 46 | ||||||||
| Sunspot number: | 126 | 267 | 176 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 76 | 161 | 100 | (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): | 139 | 147 | 141 | ||||||||
| 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 | 175.0 (1) | 48.7 (2A) / 137.4 (2B) / 156.5(2C) | (122.0 projected, +3.1) | (12.6) | |
| 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.
