Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 31, 2022 at 11:25 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 unsettled to minor storm on December 30 under the influence fo effects from CH1122. Solar wind speed at SOHO ranged between 489 and 660 km/sec. The high latitude magnetometer at Andenes recorded active to severe storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 162 - increasing 28 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 124.21). The Potsdam WDC planetary A index was 29 (STAR Ap - based on the mean of three hour interval ap indices: 28.6). Three hour interval K indices: 54444443 (planetary), 44435443 (Boulder), 75455655 (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: 283) and in 10 active regions using 1K resolution (SN: 177) SDO/HMI images.

Region 13171 [N23W77] decayed slowly and quietly.
Region 13172 [S35W48] decayed slowly and quietly.
Region 13173 [N23W28] decayed slowly and quietly.
Region 13175 [S21W07] was quiet and stable.
Region 13176 [N18E10] produced a couple of M flares and may be capable of generating a major flare. Some decay was observed in the trialing spot section.
Region 13177 [S18E45] was mostly quiet and stable. C1 flare: C1.8 @ 23:04 UT
Region 13178 [S04W80] decayed slowly as it rotated to the southwest limb.
Region 13179 [N13W23] developed further and has minor polarity intermixing. C and minor M class flares are possible.

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N17E68] was mostly quiet and stable. The northern spots were split off into AR S8135. C1 flare: C1.9 @ 04:11 UT
New region S8135 [N21E70] remains capable of producing M class flares. Due to foreshortening the classification for the region is uncertain.
New region S8136 [N31E12] was observed with tiny spots in an old plage area.
New region S8137 [S26E45] was observed with tiny spots in an old plage area.
New region S8138 [S01W37] emerged with a tiny spot near the equator.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.1 00:23   S8135 GOES16  
C2.2 00:39   13179 GOES16  
C2.3 05:01   S8133 GOES16  
C2.7 05:13   13169 GOES16 simultaneous flare in AR 13176
C3.9 07:36   13169 GOES16  
C5.5 07:52   S8135 GOES16  
C5.3 09:08   13169 GOES16  
C9.6 11:14   S8135 GOES16  
C3.1 13:53   13176 GOES16  
C4.5 14:07   S8135 GOES16  
M1.4/1B 15:28 N20E09 13176 GOES16  
C3.1 16:52 N18E78 S8133 GOES16  
C4.0 19:10   13176 GOES16  
M3.7/2N 19:38   13176 GOES16 CME?
C2.6 21:35 N27E44   GOES16 unnumbered AR

Coronal mass ejections (CMEs)

December 28-30: 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 active conditions are expected for December 31 due to effects from CH1122. Mostly quiet conditions are likely on January 1-3. Quiet to minor storm conditions are expected on January 4-5 due to effects from CH1123.

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
13171 2022.12.18
2022.12.19
2 4 3 N23W79 0030 HAX HAX location: N23W77
13172 2022.12.20
2022.12.21
1 6 2 S35W50 0010 AXX BXO location: S35W48
13173 2022.12.22
2022.12.22
3 11 3 N25W29 0020 HSX CSO

area: 0030

location: N23W28

13175 2022.12.24
2022.12.25
  4 4 S20W11 0012   AXX location: S21W07
S8120 2022.12.24       N20W48            
S8121 2022.12.24       S07W47            
S8123 2022.12.25       S17W47            
13176 2022.12.25
2022.12.26
14 49 27 N20E10 0420 EKI EKI beta-gamma

area: 0530

13178 2022.12.27
2022.12.29
2 1 1 S03W84 0020 CRO HRX area: 0010

location: S04W80

13177 2022.12.27
2022.12.28
5 22 11 S17E44 0170 DAO CAI area: 0340
S8128 2022.12.27       N05W08            
S8129 2022.12.27       N18W57            
13179 2022.12.28
2022.12.29
11 33 16 N13W24 0070 DAO DAI beta-gamma

location: N13W23

area: 0250

S8133 2022.12.29   3 3 N17E68 0120   DSO split into S8135
S8134 2022.12.29       S38W12          
13180 2022.12.30 3     N19E68 0120   DAO     SWPC considers AR S8133 and S8135 as one region
S8135 2022.12.30   13 7 N21E70 0230   DAO    
S8136 2022.12.30   2   N31E12 0004   AXX    
S8137 2022.12.30   4   S26E45 0004   AXX    
S8138 2022.12.30   1   S01W37 0001   AXX    
Total spot count: 41 153 76  
Sunspot number: 121 283 176  (total spot count + 10 * number of spotted regions)
Weighted SN: 79 201 124  (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): 133 156 142  

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
2022.12 147.3 (1)   107.4 (2A) / 111.1 (2B) / 134.4 (2C) (107.1 projected, +4.8) (11.1)
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.