The geomagnetic field was quiet to minor storm on December 23 under the influence of effects related to CH1121. Solar wind speed at SOHO ranged between 481 and 575 km/sec. The high latitude magnetometer at Andenes recorded unsettled to major storm levels.
Solar flux density measured at 20h UT on 2.8 GHz was 127.7 - increasing 20.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 123.59). The Potsdam WDC planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 20.6). Three hour interval K indices: 42434425 (planetary), 32536524 (Boulder), 63445446 (Andenes).
The background x-ray flux is at the class B7 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 211) and in 7 active regions using 1K resolution (SN: 127) SDO/HMI images.
Region 13168 [S15W49] was quiet and stable.
Region 13169 [N20W07] became better defined in the trailing spot
section as the leading part of AR 13171 and the trailing part of AR 13169
separated. The region developed both in the intermediate and trailing spot
sections. C1 flares: C1.0 @ 16:17, C1.8 @ 12:37 UT
Region 13170 [S19W00] was mostly quiet and stable. C1 flares:
C1.4 @ 14:15, C1.5 @ 23:22, C1.6 @ 23:36 UT
Region 13171 [N24E15] was mostly quiet and stable. C1 flare: C1.0 @
16:17 UT
Region 13172 [S33E37] was quiet and stable.
Region 13173 [N25E63] gained a few spots and was quiet.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8113 [N21W19] was quiet and stable.
New region S8116 [S17E04] emerged with a tiny spot before
noon, then decayed slowly.
New region S8117 [S25E11] emerged with a tiny spot.
AR 13163 behind the southwest limb was the source of a C1.0 flare at 00:38, C1.9 flare at 01:31, a C1.2 flare at 02:03, a C1.4 flare at 03:36, a C1.2 flare at 04:58 and a C1.0 flare at 18:56 UT
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.3 | 10:51 | behind SW limb | 13163 | GOES16 | |
| C6.6 | 14:46 | 13170 | GOES16 |
December 21-23: No obviously Earth directed CMEs were observed in available LASCO imagery.
December 24: A filament eruption was observed near AR 13171 starting
at approximately 00:38 UT. LASCO imagery displays a partial halo CME that
could reach Earth on December 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 northern hemisphere coronal hole (CH1121) was Earth facing on December 20-21. Another recurrent northern hemisphere coronal hole (CH1122) will likely rotate across the central meridian on December 25-26.
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 minor storm conditions are expected for December 24 due to effects from CH1121 with quiet to unsettled conditions likely on December 25-26.
| 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 | ||||||||||
| 13168 | 2022.12.13 2022.12.14 |
1 | 5 | 2 | S16W53 | 0050 | HSX | CSO |
 |
 |
area: 0090 location: S15W49 |
| 13169 | 2022.12.16 2022.12.17 |
9 | 61 | 36 | N19W09 | 0260 | EHO | FSI |
 |
 |
area: 0390 location: N20W07 |
| 13170 | 2022.12.17 2022.12.17 |
3 | 20 | 4 | N01W03 | 0010 | BXO | BXO |
 |
 |
area: 0020 location: S19W00 SWPC position is far off |
| S8102 | 2022.12.17 | N06W31 | reversed polarities | ||||||||
| 13171 | 2022.12.18 2022.12.19 |
7 | 14 | 9 | N24E12 | 0250 | DKO | CAO |
 |
 |
location: N24E15 |
| S8106 | 2022.12.18 | N26W40 | |||||||||
| S8107 | 2022.12.18 | S15W13 | |||||||||
| 13174 | 2022.12.19 2022.12.22 |
3 | N23E25 | 0010 | BXO |
 |
region should be deleted, spots are the trailing spots of AR 13171 | ||||
| S8109 | 2022.12.19 | N09W11 | |||||||||
| S8110 | 2022.12.19 | S05W37 | reversed polarities | ||||||||
| 13172 | 2022.12.20 2022.12.21 |
3 | 9 | 4 | S34E36 | 0020 | CRO | CAO |
 |
 |
location: S33E37 |
| S8113 | 2022.12.20 | 2 | 1 | N21W19 | 0004 | AXX |
 |
 |
|||
| 13173 | 2022.12.22 2022.12.22 |
4 | 8 | 1 | N25E63 | 0050 | CAO | CAO |
 |
 |
was AR S8114 area: 0130 |
| S8115 | 2022.12.22 | S03E17 |
 |
||||||||
| S8116 | 2022.12.23 | 1 | S17E04 | 0001 | AXX |
 |
|||||
| S8117 | 2022.12.23 | 1 | S25E11 | 0002 | AXX |
 |
|||||
| Total spot count: | 30 | 121 | 57 | ||||||||
| Sunspot number: | 100 | 211 | 127 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 63 | 146 | 82 | (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 | 116 | 102 | ||||||||
| 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 |
| 2021.05 | 75.3 | 77.1 | 21.2 | 25.8 (+1.0) | 6.50 |
| 2021.06 | 79.4 | 81.8 | 25.0 | 27.6 (+1.8) | 5.52 |
| 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 | 64.8 (+4.7) | 10.46 |
| 2022.03 | 117.0 | 115.8 | 78.6 | 68.9 (+4.1) | 10.20 |
| 2022.04 | 130.8 | 131.7 | 84.0 | 73.1 (+4.2) | 11.79 |
| 2022.05 | 133.8 | 136.8 | 96.5 | 77.3 (+4.2) | 7.48 |
| 2022.06 | 116.1 | 119.8 | 70.3 | (80.7 projected, +3.6) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | (85.7 projected, +5.0) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 75.4 | (91.4 projected, +5.7) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.3 | (96.3 projected, +4.9) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.4 | (99.5 projected, +3.2) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 77.6 | (102.3 projected, +2.8) | 9.33 |
| 2022.12 | 145.6 (1) | 84.1 (2A) / 114.6 (2B) / 118.3 (2C) | (107.1 projected, +4.8) | (8.8) | |
| 2023.01 | (113.1 projected, +6.0) | ||||
| 2023.02 | (118.1 projected, +5.0) | ||||
| 2023.03 | (121.2 projected, +3.1) | ||||
| 2023.04 | (126.6 projected, +5.4) | ||||
| 2023.05 | (132.4 projected, +5.8) | ||||
| 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.
