Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 4, 2023 at 09:20 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 (January 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (January 1, 2023) 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 (January 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (January 1, 2023) 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 to unsettled on January 3. Solar wind speed at SOHO ranged between 373 and 459 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 148.5 - increasing 0.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 124.85). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.9). Three hour interval K indices: 20110223 (planetary), 10211223 (Boulder), 20001336 (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 14 active regions using 2K resolution (SN: 292) and in 12 active regions using 1K resolution (SN: 178) SDO/HMI images.

Region 13176 [N19W46] decayed significantly losing all mature penumbra on the trailing spots. C1 flares: C1.4 @ 00:14, C1.1 @ 01:10 UT
Region 13177 [S18W08] gained small spots while the main penumbral areas showed signs of decay.
Region 13179 [N13W77] was quiet and stable.
Region 13181 [S19E44] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N16E17] developed slowly and quietly.
S8135 [N20E19] was mostly quiet and stable. C1 flares: C1.4 @ 23:04 UT
S8137 [S25W02] was quiet and stable.
S8143 [N21W02] was quiet and stable.
New region S8147 [S16W36] emerged before noon, then decayed slowly.
New region S8148 [N30W46] emerged with a tiny spot.
New region S8149 [N33E15] emerged with a tiny spot.
New region S8150 [N14E32] emerged with a tiny spot.
New region S8151 [N11W42] emerged with a tiny spot.
New region S8152 [S19E19] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.7 04:58   13177 GOES16  
C3.2 06:46 behind SE limb   GOES16  
C4.0 10:36 behind SE limb   GOES16 very long duration event
C3.4 12:13   S8135 GOES16  
C2.8 16:32   13177 GOES16  
C2.4 00:00 behind SE limb   GOES16  

Coronal mass ejections (CMEs)

January 1-3: 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 (CH1123) was 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 on January 4-5 due to effects from CH1123. Quiet to unsettled is likely on January 6-7.

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
13173 2022.12.22
2022.12.22
      N24W84          

location: N23W81

13175 2022.12.24
2022.12.25
      S20W67           location: S21W59
13176 2022.12.25
2022.12.26
12 26 8 N19W43 0110 ESI CAI

location: N19W46

13177 2022.12.27
2022.12.28
11 47 20 S18W09 0190 CAI CAI  
13179 2022.12.28
2022.12.29
2 3 3 N13W80 0290 DKO DSO

location: N13W77

area: 0400

S8133 2022.12.29   23 12 N16E17 0250   DSO  
13180 2022.12.30 12     N18E17 0240 DSI       SWPC consider AR S8133 and S8135 to be one region
S8135 2022.12.30   17 4 N20E19 0200   DSO  
S8136 2022.12.30       N31W40            
S8137 2022.12.30   7 2 S25W05 0010   BXO  
13181 2022.12.31
2023.01.01
2 11 4 S19E44 0100 HSX CAO area: 0180
S8140 2022.12.31       N28W09            
S8141 2022.12.31       N18W53            
S8142 2023.01.01       N14W29            
S8143 2023.01.01   6 1 N21W02 0010   BXO    
S8144 2023.01.01       N27W31          
S8145 2023.01.02       S25W45          
S8146 2023.01.02       S13E25            
S8147 2023.01.03   3   S16W36 0005   BXO    
S8148 2023.01.03   1 1 N30W46 0002   AXX    
S8149 2023.01.03   1 1 N33E15 0003   AXX    
S8150 2023.01.03   1 1 N14E32 0004   AXX    
S8151 2023.01.03   1   N11W42 0001   AXX    
S8152 2023.01.03   5 1 S19E19 0010   BXO    
Total spot count: 39 152 58  
Sunspot number: 89 292 178  (total spot count + 10 * number of spotted regions)
Weighted SN: 69 182 88  (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): 98 161 142  

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
2021.06 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 64.7 (+4.6) 10.46
2022.03 117.0 115.8 78.6 68.7 (+4.0) 10.20
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.2 (+4.2) 7.48
2022.06 116.1 119.8 70.3 80.9 (+3.7) 8.20
2022.07 125.4 129.5 91.4 (86.0 projected, +5.1) 9.51
2022.08 114.2 117.1 74.6 (91.4 projected, +5.4) 10.92
2022.09 135.1 136.5 96.0 (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
2022.12 147.9 143.4 113.1 (107.1 projected, +4.8) 11.2
2023.01 149.2 (1)   8.9 (2A) / 92.3 (2B) / 137.9 (2C) (113.1 projected, +6.0) (8.7)
2023.02       (118.2 projected, +5.1)  
2023.03       (121.3 projected, +3.1)  
2023.04       (126.7 projected, +5.4)  
2023.05       (132.5 projected, +5.8)  
2023.06       (135.7 projected, +3.2)  
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.