Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 3, 2023 at 07:05 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 2. Solar wind speed at SOHO ranged between 368 and 538 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 146 - increasing 2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 124.69). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.6). Three hour interval K indices: 22121123 (planetary), 11221212 (Boulder), 42211145 (Andenes).

The background x-ray flux is at the class B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 216) and in 9 active regions using 1K resolution (SN: 157) SDO/HMI images.

Region 13176 [N19W31] decayed slowly losing spots and area.
Region 13177 [S18E04] decayed slowly and quietly.
Region 13179 [N13W64] decayed slowly and quietly.
Region 13181 [S19E57] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N16E29] developed slowly and quietly.
S8135 [N21E32] decayed slowly and produced several low level C flares. C1 flares: C1.6 @ 05:29, C1.1 @ 16:08, C1.8 @ 21:43 UT
S8137 [S25E12] was quiet and stable.
S8144 [N27W18] was quiet and stable.
S8145 [S25W32] was quiet and stable.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C9.4/1F 06:21 N20W28 13176 GOES16  
C2.8 09:56 N20E37 S8135 GOES16  
C2.3 11:39 N21E42 S8135 GOES16  
C3.0 11:52   S8135 GOES16  
C2.0 22:16 N20E31 S8135 GOES16  
C3.2 23:11 N18E33 S8135 GOES16  

Coronal mass ejections (CMEs)

December 31 - January 2: 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are expected for January 3. Quiet to minor storm conditions are likely 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
13173 2022.12.22
2022.12.22
1     N24W70 0010 AXX    

spotless

location: N23W68

13175 2022.12.24
2022.12.25
      S20W53           location: S21W46
13176 2022.12.25
2022.12.26
15 36 21 N19W29 0230 EAO EAI

location: N19W31

13177 2022.12.27
2022.12.28
7 32 17 S18E04 0200 CAI CAO  
S8128 2022.12.27       N05W47            
13179 2022.12.28
2022.12.29
4 10 5 N14W64 0380 DKO DSO

location: N13W64

S8133 2022.12.29   19 9 N16E29 0170   DSO  
13180 2022.12.30 6     N19E30 0230 DSI       SWPC consider AR S8133 and S8135 to be one region
S8135 2022.12.30   14 8 N21E32 0200   DSO  
S8136 2022.12.30       N31W27            
S8137 2022.12.30   6 3 S25E12 0010   BXO  
13181 2022.12.31
2023.01.01
1 2 2 S19E58 0050 HAX HAX area: 0200

location: S19E57

S8140 2022.12.31       N28E04            
S8141 2022.12.31       N18W40            
S8142 2023.01.01       N14W16          
S8143 2023.01.01       N17E13          
S8144 2023.01.01   2 1 N27W18 0006   AXX  
S8145 2023.01.01   5 1 S25W32 0010   BXO  
S8146 2023.01.01       S13E38          
Total spot count: 34 126 67  
Sunspot number: 94 216 157  (total spot count + 10 * number of spotted regions)
Weighted SN: 64 156 97  (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): 103 119 126  

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 64.8 (+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 81.0 (+3.7) 8.20
2022.07 125.4 129.5 91.4 (86.1 projected, +5.1) 9.51
2022.08 114.2 117.1 75.4 (91.5 projected, +5.4) 10.92
2022.09 135.1 136.5 96.3 (96.4 projected, +4.9) 12.18
2022.10 133.5 132.7 95.4 (99.6 projected, +3.2) 11.16
2022.11 123.4 120.7 77.6 (102.4 projected, +2.8) 9.33
2022.12 147.9 143.4 113.1 (107.2 projected, +4.8) 11.2
2023.01 149.5 (1)   6.1 (2A) / 94 (2B) / 137.0 (2C) (113.2 projected, +6.0) (10.1)
2023.02       (118.2 projected, +5.0)  
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.