The geomagnetic field was quiet on December 17. Solar wind speed at SOHO ranged between 298 and 356 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.
Solar flux density measured at 20h UT on 2.8 GHz was 154.6 - increasing 35.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 123.36). The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.8). Three hour interval K indices: 12000000 (planetary), xxxxxxxx (Boulder), 31100000 (Andenes).
The background x-ray flux is at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 265) and in 10 active regions using 1K resolution (SN: 158) SDO/HMI images.
Region 13160 [N23W67] was quiet and stable.
Region 13162 [S13W49] was quiet and stable.
Region 13163 [S19W28] gained area and spots and has polarity
intermixing. C and M class flares are possible.
Region 13165 [S22W83] rotated partly partly out of view and produced
several C flares.
Region 13166 [S07W38] decayed slowly and was mostly quiet. C1
flare: C1.6 @ 21:42 UT
Region 13167 [N19W52] decayed slowly and quietly. C1 flare: C1.7 @
18:48 UT
Region 13168 [S16E29] was quiet and stable.
New region 13169 [N20E72] rotated into view on December 16 with SWPC
numbering the region the following day. The region produced several C flares
and the only M class flare of the day. C1 flare: C1.8 @ 16:04 UT
New region 13170 [S19E75] rotated into view. C1 flares: C1.9 @ 10:14
UT
Spotted regions not observed (or interpreted
differently) by SWPC:
S8097 [N21E15] gained tiny spots.
New region S8102 [N06E47] emerged with a tiny spot and has
reversed polarities.
New region S8103 [N08E05] emerged with a tiny spot.
New region S8104 [S24W10] emerged with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C8.7 | 01:08 | 13165 | GOES16 | ||
| C4.8 | 01:23 | 13165 | GOES16 | ||
| C5.2 | 01:44 | 13165 | GOES16 | ||
| C3.2 | 02:26 | 13165 | GOES16 | ||
| C2.0 | 03:59 | 13165 | GOES16 | ||
| C2.5 | 04:34 | 13169 | GOES16 | ||
| C2.1 | 05:28 | 13169 | GOES16 | ||
| C2.8 | 05:53 | 13169 | GOES16 | ||
| C2.1 | 06:32 | 13165 | GOES16 | ||
| C3.0 | 08:54 | 13166 | GOES16 | simultaneous flare in AR 13163 | |
| C2.0 | 15:54 | 13162 | GOES16 | ||
| C2.6 | 16:41 | 13169 | GOES16 | ||
| C5.0 | 17:36 | 13170 | GOES16 | ||
| M1.0/1N | 19:53 | 13169 | GOES16 | ||
| C3.2 | 22:20 | 13163 | GOES16 |
December 15-17: No obviously Earth directed CMEs were observed in available LASCO imagery.
[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 southern hemisphere coronal hole (CH1119) rotated across the central meridian on December 14-17. CH1119 could be too far to the south to cause a disturbance. A recurrent northern hemisphere coronal hole (CH1120) will be Earth facing on December 17-18.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is good to very good. Propagation on long distance northeast-southwest paths is poor.
Quiet geomagnetic conditions are expected for December 18-20, however, a high speed stream from CH1119 could cause a few unsettled and active intervals on December 18-19.
| 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 | ||||||||||
| 13159 | 2022.12.05 2022.12.06 |
N29W87 | location: N29W77 | ||||||||
| 13160 | 2022.12.06 2022.12.06 |
1 | 1 | 1 | N23W69 | 0050 | HSX | HSX |
 |
 |
location: N23W67 area: 0090 |
| 13162 | 2022.12.07 2022.12.09 |
2 | 12 | 4 | S14W51 | 0040 | HSX | CSO |
 |
 |
area: 0070 |
| 13163 | 2022.12.09 2022.12.10 |
22 | 51 | 29 | S20W26 | 0530 | EKI | DKI |
 |
 |
beta-gamma location: S19W28 area: 0750 |
| 13165 | 2022.12.10 2022.12.11 |
6 | 3 | 2 | S22W88 | 0150 | DAO | CAO |
 |
 |
|
| 13166 | 2022.12.10 2022.12.11 |
9 | 20 | 15 | S08W39 | 0170 | DSO | DAI |
 |
 |
location: S07W38 |
| 13167 | 2022.12.12 2022.12.13 |
5 | 18 | 9 | N20W53 | 0120 | CAO | DAO |
 |
 |
location: N20W52 |
| S8084 | 2022.12.12 | N20W45 | |||||||||
| S8087 | 2022.12.12 | N29W57 | |||||||||
| S8088 | 2022.12.12 | S32W58 | |||||||||
| S8091 | 2022.12.13 | N26W14 | |||||||||
| 13168 | 2022.12.13 2022.12.14 |
1 | 9 | 2 | S16E28 | 0050 | HSX | CSO |
 |
 |
area: 0120 location: S16E29 |
| S8093 | 2022.12.13 | S45W28 | |||||||||
| S8094 | 2022.12.13 | S09W38 | |||||||||
| S8095 | 2022.12.13 | S43W47 | |||||||||
| S8096 | 2022.12.14 | N15W21 | |||||||||
| S8097 | 2022.12.15 | 7 | 1 | N21E15 | 0012 | AXX |
 |
 |
|||
| S8098 | 2022.12.16 | S10E17 |
 |
||||||||
| S8099 | 2022.12.16 | N23W18 |
 |
||||||||
| 13169 | 2022.12.16 2022.12.17 |
2 | 6 | 3 | N20E69 | 0160 | DSO | EAO |
 |
 |
area: 0360 location: N20E72 |
| 13170 | 2022.12.17 2022.12.17 |
1 | 5 | 2 | S18E72 | 0020 | HRX | DAO |
 |
was AR S8101 location: S19E75 area: 0040 |
|
| S8102 | 2022.12.17 | 1 | N06E47 | 0002 | AXX |
 |
reversed polarities | ||||
| S8103 | 2022.12.17 | 1 | N08E05 | 0002 | AXX |
 |
|||||
| S8104 | 2022.12.17 | 1 | S24W10 | 0001 | AXX |
 |
|||||
| Total spot count: | 49 | 135 | 68 | ||||||||
| Sunspot number: | 139 | 265 | 168 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 96 | 185 | 118 | (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): | 153 | 146 | 134 | ||||||||
| 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 | 146.8 (1) | 61.1 (2A) / 114.5 (2B) / 113.0 (2C) | (107.1 projected, +4.8) | (8.6) | |
| 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.
