Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 7, 2023 at 07:15 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 (January 6, 2023)
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 very quiet on January 6. Solar wind speed at SOHO ranged between 320 and 505 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.

Solar flux density measured at 20h UT on 2.8 GHz was 172.4 - increasing 30.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 125.42). The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.8). Three hour interval K indices: 10011011 (planetary), 10101221 (Boulder), 30000033 (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: 299) and in 9 active regions using 1K resolution (SN: 178) SDO/HMI images.

Region 13177 [S18W44] decayed slowly and quietly.
Region 13181 [S18E05] decayed slowly and quietly.
Region 13182 [S17E58] produced an X1.2 flare early in the day and was otherwise mostly quiet. The region has polarity intermixing. Further major flares are possible. C1 flares: C1.8 @ 04:02, C1.5 @ 12:05, C1.7 @ 14:55, C1.9 @ 15:11 UT. The region was the source of an M1.6 flare at 00:52 UT on January 7.
Region 13183 [S17W22] developed a magnetic delta in an intermediate penumbra. Minor M class flares are possible. C1 flares: C1.5 @ 07:56, C1.3 @ 11:14, C1.8 @ 12:26, C1.3 @ 13:15, C1.8 @ 15:59 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N17W25] decayed slowly and quietly
S8135 [N21W20] decayed slowly and quietly.
S8137 [S27W35] was quiet and stable.
S8155 [S21E09] developed quickly and is a compact region with M class flare potential.
S8156 [S28W83] developed slowly as it rotated to the southwest limb. C1 flares: C1.8 @ 08:33 UT
New region S8158 [N22W61] emerged with a few spots.
New region S8159 [N19E43] was observed with tiny spots in an old plage area.

AR 13176 produced a C1.6 flare at 05:28 UT before rotating over the northwest limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.2 00:50   13182 GOES16  
X1.2/2B 00:57   13182 GOES16  
C3.5 03:34 S18W07 13183 GOES16  
C2.6 16:50   13176 GOES16  
C6.2 18:53 S16W16 13183 GOES16  
C5.0 20:27 S16W18 13183 GOES16  
C2.2 21:25   13182 GOES16  
C2.1 22:30   13182 GOES16  
C2.5 23:23 S19E65 13183 GOES16 incorrectly attributed to AR 13182 by SWPC

Coronal mass ejections (CMEs)

January 4-6: 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 northern hemisphere coronal hole (CH1124) is likely too far to the north to cause geomagnetic effects, it will be rotating across the central meridian on January 7.

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 on January 7-9.

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
13176 2022.12.25
2022.12.26
1     N19W91 0030 HSX     rotated out of view
13177 2022.12.27
2022.12.28
5 14 5 S17W48 0050 CAO CAO  
S8133 2022.12.29   13 4 N17W25 0120   CSO  
13180 2022.12.30 5     N18W23 0120 CSO       SWPC consider AR S8133 and S8135 to be one region
S8135 2022.12.30   4 1 N21W20 0120   CSO  
S8137 2022.12.30   5   S27W35 0008   BXO  
13181 2022.12.31
2023.01.01
13 29 12 S20E06 0110 DAI CAO area: 0130

location: S18E05

SWPC apparently considers this and AR S8155 as one region

S8140 2022.12.31       N28W48            
S8143 2023.01.01       N21W41            
S8146 2023.01.02       S13W14            
S8149 2023.01.03       N33W24            
S8150 2023.01.03       N14W07            
13183 2023.01.03
2023.01.05
8 38 22 S17W22 0160 DSI DSI beta-delta

area: 0230

S8153 2023.01.04       S10W00          
13182 2023.01.04
2023.01.05
9 42 23 S16E59 0450 DKI EKI beta-gamma

area: 0680

S8155 2023.01.05   33 18 S21E09 0340   DAC  
S8156 2023.01.05   3 2 S27W83 0040   CRO  
S8157 2023.01.05       S02E27          
S8158 2023.01.06   5 1 N22W61 0013   CRO    
S8159 2023.01.06   3   N19E43 0006   BXO    
Total spot count: 41 189 88  
Sunspot number: 101 299 178  (total spot count + 10 * number of spotted regions)
Weighted SN: 76 235 134  (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): 111 164 142  

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
2023.01 154.2 (1)   18.3 (2A) / 94.5 (2B) / 137.2 (2C) (113.1 projected, +6.0) (9.1)
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.