Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 17, 2022 at 10:20 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 16. Solar wind speed at SOHO ranged between 316 and 381 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 163.1 - increasing 48.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 123.27). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.6). Three hour interval K indices: 21000011 (planetary), xxxxxxxx (Boulder), 40010132 (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: 239) and in 8 active regions using 1K resolution (SN: 143) SDO/HMI images.

Region 13160 [N23W54] was quiet and stable.
Region 13162 [S14W36] was quiet and stable.
Region 13163 [S19W13] decayed in the trailing and intermediate spot sections while the main penumbra gained area.
Region 13165 [S20W76] matured and lost the magnetic delta. Flare frequency has decreased significantly early on December 17.
Region 13166 [S08W25] developed slowly and quietly.
Region 13167 [N20W39] decayed slowly and quietly.
Region 13168 [S15E43] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8097 [N25E21] decayed slowly and quietly.
New region S8098 [S10E30] emerged with a tiny spot.
New region S8099 [N23W05] emerged with a tiny spot.
New region S8100 [N20E83] rotated partly into view and has produced several flares over the last couple of days. M class flaring is likely.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
M3.5 02:01   13165 GOES16 LDE
C5.1 03:30   13165 GOES16  
C4.3 03:53   13165 GOES16  
C4.7 04:11   S8100 GOES16  
M1.2 04:59   13163 GOES16 simultaneous flare in AR S8100
M1.3 05:48   13163 GOES16  
M1.3 05:48   13163 GOES16  
C6.0 06:22   13165 GOES16  
M1.2/1F 06:42 S20W39 13165 GOES16  
C5.1 07:19 S20W39 13165 GOES16  
M1.6 07:38   13165 GOES16  
M1.5 09:05 S20W39 13165 GOES16  
M1.1 09:43   13165 GOES16 wrongly attributed to AR 13163 by SWPC
M4.0 10:19   13165 GOES16  
M1.2 11:05   13165 GOES16  
C8.5 11:40   13165 GOES16  
C4.7 13:29 S22W71 13165 GOES16  
C5.8 13:53   13165 GOES16  
M2.4 14:40   13165 GOES16  
M1.1 15:25   13165 GOES16  
M1.2 15:40   13165 GOES16  
C7.0 16:50   13165 GOES16  
C4.3 18:11   13165 GOES16  
C3.8 18:34   13165 GOES16  
C9.1 19:11   13165 GOES16  
C3.7 20:07   13165 GOES16  
C8.9 21:04   13165 GOES16  
C4.9 22:24   13165 GOES16  
C5.4 23:16   13165 GOES16  
C7.9 23:39   13165 GOES16  

Coronal mass ejections (CMEs)

December 14-16: 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 southern hemisphere coronal hole (CH1119) will rotate 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) could become Earth facing on December 17-18.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is good. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are expected for December 17-19, however, a high speed stream from CH1119 could cause a few unsettled and active intervals on December 17-18.

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
13159 2022.12.05
2022.12.06
      N29W73           location: N29W64
13160 2022.12.06
2022.12.06
  2 2 N23W56     CSO

location: N22W54

area: 0090

13162 2022.12.07
2022.12.09
  8 3 S14W36     CSO area: 0110
13163 2022.12.09
2022.12.10
  44 24 S19W11     EKI beta-gamma

location: S19W13

area: 0620

13165 2022.12.10
2022.12.11
  12 8 S20W76     EKI beta-gamma-delta

area: 0800

13166 2022.12.10
2022.12.11
  29 16 S08W25     DAI

area: 0280

S8080 2022.12.10       S03W57            
S8081 2022.12.11       N17W48            
13167 2022.12.12
2022.12.13
  23 8 N21W40     DAO area: 0180

location: N20W39

S8084 2022.12.12       N20W32            
S8087 2022.12.12       N29W44            
S8088 2022.12.12       S32W45            
S8091 2022.12.13       N26W01            
13168 2022.12.13
2022.12.14
  4 1 S15E39     CSO area: 0120

location: S15E43

S8093 2022.12.13       S45W15            
S8094 2022.12.13       S09W15            
S8095 2022.12.13       S43W34            
S8096 2022.12.14       N15W08          
S8097 2022.12.15   4   N25E21 0004   BXO  
S8098 2022.12.16   1   S10E30 0003   AXX    
S8099 2022.12.16   1   N23W05 0002   AXX    
S8100 2022.12.16   1 1 N20E83 0210   HSX    
Total spot count:   129 63  
Sunspot number:   239 143  (total spot count + 10 * number of spotted regions)
Weighted SN:   179 113  (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):   131 114  

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
2022.12 146.3 (1)   54.6 (2A) / 112.9 (2B) / 111.6 (2C) (107.1 projected, +4.8) (9.0)
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.