The geomagnetic field was quiet to active on March 9. Solar wind speed at SOHO ranged between 369 and 468 km/sec. The high latitude magnetometer at Andenes recorded unsettled to minor storm levels. The earthbound ejecta from the March 6 CME appears to have become embedded in the solar wind and was the most likely cause of a disturbance starting early on March 9.
Solar flux density measured at 20h UT on 2.8 GHz was 178.8 - decreasing 29.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 136.73). The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.1). Three hour interval K indices: 24443322 (planetary), 23533232 (Boulder), 35444444 (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 16 active regions using 2K resolution (SN: 304) and in 15 active regions using 1K resolution (SN: 222) SDO/HMI images.
Region 13238 [N09W70] was quiet and stable.
Region 13239 [N33W46] was quiet and stable.
Region 13240 [S19W38] was quiet and stable.
Region 13241 [N28W32] was quiet and stable.
Region 13242 [N10W32] decayed quickly and produced a few C flares. C1
flares: C1.4 @ 06:31 UT
Region 13245 [S22W03] still has polarity intermixing in the penumbrae
to the east of the main penumbra. A major flare is possible. C1 flares: C1.5
@ 11:02, C1.9 @ 12:46 UT
Region 13246 [N24E15] was quiet and stable.
Region 13247 [S23E28] was quiet and stable. AR 13250 was split off.
Region 13248 [N15W81] developed as it rotated to the northwest limb.
An M class flare is possible as the region transits the limb. C1 flares:
C1.8 @ 00:06, C1.4 @ 06:56 UT
Region 13249 [S12E49] was quiet and stable.
New region 13250 [S19E46] was split off from AR 13247 as new flux
emerged. Many small spots formed. C1 flares: C1.5 @ 08:07, C1.6 @ 19:29 UT
New region 13251 [S13E69] rotated into view on March 8 and was
numbered the next day by SWPC.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8346 [N24E15] reemerged with tiny spots.
S8348 [N22E60] was mostly quiet and stable
New region S8351 [N12E73] rotated into view with a mature spot.
New region S8353 [S29W21] emerged with a tiny spot.
Two coronal shocks were recorded (over all limbs and the north and south pole) at 13:18 and 20:48 UT, in both cases immediately followed by a CME. The first event, taking into account the distribution of the ejecta, was likely 5-6 days behind the west limb and was observed as a full halo CME. The second CME was smaller with most of the ejecta seen off the south pole and was probably also backsided. However, the C6 flare in AR 13245 at 20:24 UT may be within the time frame expected from the CME source. The available data will be reevaluated today.
AR 13244 behind the southwest limb was the source of a C1.8 flare at 10:11 UT.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.2 | 00:54 | N11W10 | 13242 | GOES16 | |
| C3.9 | 01:19 | 13248 | GOES16 | ||
| C3.1 | 09:04 | 13245 | GOES16 | LDE | |
| C3.0/1F | 13:53 | N12W11 | 13242 | GOES16 | |
| C3.5 | 14:14 | 13242 | GOES16 | ||
| C2.1 | 16:37 | 13245 | GOES16 | ||
| C2.4 | 18:16 | 13250 | GOES16 | ||
| C2.6 | 18:30 | 13245 | GOES16 | ||
| C3.1 | 20:11 | 13245 | GOES16 | ||
| C6.2 | 20:24 | 13245 | GOES16 | ||
| C2.9 | 21:09 | 13250 | GOES16 | ||
| C3.4 | 23:31 | S8348 | GOES16 |
March 7-9: 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 northern hemisphere coronal hole (CH1134] will likely rotate into 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 active conditions are likely on March 10 due to CME effects. Quiet to unsettled is likely on March 11-12.
| 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 | ||||||||||
| 13238 | 2023.02.26 2023.02.27 |
1 | 1 | 1 | N09W72 | 0010 | AXX | AXX |
 |
 |
location: N09W70 area: 0003 |
| 13239 | 2023.02.27 2023.02.28 |
1 | 1 | 1 | N32W41 | 0070 | HSX | HSX |
 |
 |
location: N33W46 area: 0110 |
| 13241 | 2023.02.28 2023.03.01 |
1 | 7 | 2 | N28W36 | 0020 | HSX | CSO |
 |
 |
location: N28W32 area: 0040 |
| 13240 | 2023.02.28 2023.03.01 |
3 | 2 | S09W63 | 0010 | BXO |
 |
 |
location: S19W38 SWPC on March 6 moved the location to near AR S8327 |
||
| 13242 | 2023.03.01 2023.03.02 |
13 | 34 | 13 | N09W29 | 0170 | ESI | EAO |
 |
 |
location: N10W32 |
| 13245 | 2023.03.02 2023.03.03 |
11 | 43 | 21 | S24W07 | 0250 | DHO | DHI |
 |
 |
beta-gamma area: 0430 location: S22W03 |
| S8330 | 2023.03.03 | S17W14 | |||||||||
| S8331 | 2023.03.03 | S30W50 | |||||||||
| 13246 | 2023.03.04 2023.03.05 |
1 | 5 | 4 | N25E14 | 0040 | HAX | DSO |
 |
 |
location: N24E15 area: 0080 |
| S8335 | 2023.03.04 | N22W28 | |||||||||
| S8336 | 2023.03.04 | S08W20 | |||||||||
| 13247 | 2023.03.05 2023.03.06 |
5 | 18 | 9 | S24E28 | 0070 | CSO | CSO |
 |
 |
location: S23E28 area: 0110 |
| 13248 | 2023.03.05 2023.03.06 |
6 | 1 | 1 | N15W85 | 0020 | CRO | DRO |
 |
 |
location: N15W81 area: 0200 |
| S8340 | 2023.03.05 | N28W57 | |||||||||
| S8341 | 2023.03.05 | S04W35 |
 |
||||||||
| S8343 | 2023.03.06 | S12W04 | |||||||||
| 13249 | 2023.03.07 2023.03.07 |
1 | 3 | 2 | S11E47 | 0030 | HAX | HSX |
 |
 |
location: S12E49 area: 0100 |
| S8346 | 2023.03.07 | 3 | N33E36 | 0003 | AXX |
 |
|||||
| S8348 | 2023.03.08 | 4 | 2 | N22E60 | 0010 | BXO |
 |
 |
|||
| 13251 | 2023.03.08 2023.03.09 |
1 | 1 | 1 | S13E69 | 0050 | HSX | HSX |
 |
 |
area: 0110 |
| S8350 | 2023.03.08 | N13E10 |
 |
||||||||
| S8351 | 2023.03.09 | 1 | 1 | N12E73 | HSX |
 |
|||||
| 13250 | 2023.03.09 2023.03.09 |
4 | 18 | 11 | S20E45 | 0010 | BXO | DRI |
 |
split off from AR 13247 location: S19E46 area: 0070 was AR S8352 |
|
| S8353 | 2023.03.09 | 1 | 1 | S29W21 | 0003 | AXX |
 |
||||
| Total spot count: | 45 | 144 | 72 | ||||||||
| Sunspot number: | 155 | 304 | 222 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 93 | 200 | 128 | (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): | 171 | 167 | 178 | ||||||||
| 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 | 177.4 (1) | 40.3 (2A) / 138.9 (2B) / 159.9 (2C) | (122.0 projected, +3.1) | (13.7) | |
| 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.
