Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 29, 2022 at 12:10 UT. Minor update added at 20:15 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data since 2003.01 (December 4, 2022)
Solar cycle Solar cycles 23-25 (December 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (December 1, 2022) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (July 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (December 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (December 1, 2022) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (August 21, 2022) Cycle 25 spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing Research: Solar Cycle 25 Started on November 17, 2019 with 365 Days Smoothing

Recent activity

The geomagnetic field was quiet on December 28. Solar wind speed at SOHO ranged between 443 and 603 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density at 20h UT on 2.8 GHz was not provided by DRAO/Penticton. Instead 140.6 (estimated from Almaty data) is a replacement value - increasing 21.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 123.78). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.4). Three hour interval K indices: 22111101 (planetary), 22202211 (Boulder), 52100002 (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 11 active regions using 2K resolution (SN: 231) and in 9 active regions using 1K resolution (SN: 139) SDO/HMI images.

Region 13169 [N21W72] decayed slowly producing a few C flares. C1 flares: C1.7 @ 07:33, C1.7 @ 08:55, C1.8 @ 14:16, C1.6 @ 14:43, C1.4 @ 15:16 UT
Region 13171 [N23W50] was quiet and stable.
Region 13172 [S37W20] developed slowly and quietly.
Region 13173 [N23W02] decayed slowly and quietly.
Region 13175 [S21E17] was quiet and stable.
Region 13176 [N18E37] matured quietly and gained area. C1 flares: C1.5 @ 13:43 UT
New region 13177 [S18E70] rotated into view on December 27 and was numbered by SWPC the following day. C1 flares: C1.8 @ 10:36 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S8122 [N19W51] was quiet and stable.
S8126 [S04W55] was first observed at noon on December 27 with a tiny spot, became spotless later the same day, and then reemerged with new flux and several spots on December 28.
New region S8130 [N30W49] emerged with tiny spots.
New region S8131 [N12E03] emerged with tiny spots.

An active region behind the northeast limb was the source of a long duration M1.2 flare peaking at 07:27 UT on December 29. C1 flare: C1.6 @ 21:57 UT

Minor update added at 19:15 UT: AR S8133 is rotating into view at the northeast limb. So far 2 moderately large spots are visible, although at some distance from each other, maybe two separate groups. The region has produced 2 M class flares today.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 00:17   13176 GOES16  
C5.0 02:37 behind NE limb   GOES16  
C6.0 02:56 behind NE limb   GOES16  
C2.2 05:00   13177 GOES16  
C2.2 16:57   13169 GOES16  
C2.3 17:25   13169 GOES16  
C3.0 17:36 behind NE limb   GOES16  
C2.1 20:11   13177 GOES16  

Coronal mass ejections (CMEs)

December 26-28: No obviously Earth directed CMEs were observed in available LASCO imagery.

Coronal holes

[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 (CH1122) rotated across the central meridian on December 25-27. A recurrent trans equatorial coronal hole (CH1123) will likely become Earth facing on January 1-2.

Propagation

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.

Forecast

Quiet to minor storm conditions are expected for December 29-31 due to effects from CH1122.

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.

Active solar regions


(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
13169 2022.12.16
2022.12.17
8 13 8 N22W69 0230 FAC FSO

area: 0340

location: N21W72

13170 2022.12.17
2022.12.17
      S19W72        

location: S14W66

13171 2022.12.18
2022.12.19
3 9 3 N24W51 0080 HAX CAO location: N23W50
13172 2022.12.20
2022.12.21
  20 5 S36W18 0030   CRO location: S37W20
13173 2022.12.22
2022.12.22
2 11 5 N24W03 0040 HSX CAO

area: 0060

location: N23W02

S8115 2022.12.22       S03W48            
S8117 2022.12.23       S22W47            
13175 2022.12.24
2022.12.25
2 13 2 S22E17 0010 BXO CRO location: S21E17

area: 0030

S8120 2022.12.24       N20W22            
S8121 2022.12.24       S07W21            
S8122 2022.12.25   2   N19W51 0004   BXO  
S8123 2022.12.25       S17W21            
13176 2022.12.25
2022.12.26
10 29 14 N19E38 0300 EKI EKO location: N18E37

area: 0580

S8126 2022.12.27   12 6 S04W55 0080   DAO    
13177 2022.12.27
2022.12.28
3 5 4 S18E71 0090 HAX HKX area: 0320
S8128 2022.12.27       N05E18          
S8129 2022.12.27       N18W31          
S8130 2022.12.28   3 2 N30W49 0009   BXO    
S8131 2022.12.28   4   N12E03 0005   BXO  

 

Total spot count: 28 121 49  
Sunspot number: 88 231 139  (total spot count + 10 * number of spotted regions)
Weighted SN: 58 167 95  (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): 97 127 111  

Monthly solar cycle data

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
2022.12 144.5 (1)   99.6 (2A) / 110.6 (2B) / 128.6 (2C) (107.1 projected, +4.8) (10.4)
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.

Solar cycles 24-25

Smoothed SF and sunspot numbers

 

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.