Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 5, 2023 at 08:00 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 quiet to minor storm on January 4. Solar wind speed at SOHO ranged between 362 and 550 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. What was likely a slow CME associated with the M3 flare late on December 30, was observed reaching SOHO near 02h UT. The Bz component of the IMF was initially moderately southwards causing minor storming, then swung strongly northwards after 09h UT.

Solar flux density measured at 20h UT on 2.8 GHz was 151.0 - increasing 8.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 125.02). The Potsdam WDC planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 18.9). Three hour interval K indices: 45533221 (planetary), 33353321 (Boulder), 55543210 (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 9 active regions using 2K resolution (SN: 217) and in 9 active regions using 1K resolution (SN: 158) SDO/HMI images.

Region 13176 [N18W60] decayed further and was quiet.
Region 13177 [S18W22] decayed significantly after noon, by the end of the day mature penumbra was observed only around one spot. The other penumbrae fragmented into small spots. C1 flares: C1.4 @ 12:48, C1.7 @ 13:50,C1.7 @ 17:27 UT
Region 13181 [S19E32] developed as new flux emerged. C class flaring is possible.

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N16E04] was mostly quiet and stable.
S8135 [N21E06] was mostly quiet and stable.
S8137 [S26W14] was quiet and stable.
S8152 [S18E07] was quiet and stable.
New region S8153 [S08E28] emerged with a tiny spot.
New region S8154 [S17E83] rotated partly into view revealing a large leader spot. M class flares are possible. C1 flares: C1.8 @ 09:30, C1.4 @ 10:57, C1.5 @ 15:39, C1.7 @ 22:03, C1.4 @ 23:19 UT

A C1.9 flare was recorded from a location behind the northeast limb at 08:51 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.7 07:31   S8154 GOES16  
C2.6 16:34   S8154 GOES16  
C5.2 18:29   13177 GOES16  
C8.4 18:45   13177 GOES16  

Coronal mass ejections (CMEs)

January 2-4: 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 5 due to CME effects and 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
13175 2022.12.24
2022.12.25
      S20W81           location: S21W72
13176 2022.12.25
2022.12.26
5 10 6 N19W57 0060 CSO CAI

location: N18W60

13177 2022.12.27
2022.12.28
13 33 16 S19W23 0100 CSI CAI  
13179 2022.12.28
2022.12.29
1     N14W92 0080 HSX     rotated out of view
S8133 2022.12.29   28 16 N16E04 0250   DSI  
13180 2022.12.30 11     N19E03 0240 DSI       SWPC consider AR S8133 and S8135 to be one region
S8135 2022.12.30   15 5 N21E06 0160   DSO  
S8136 2022.12.30       N31W53            
S8137 2022.12.30   10 4 S26W17 0020   BXO  
13181 2022.12.31
2023.01.01
6 24 16 S19E30 0240 CSO DAI  
S8140 2022.12.31       N28W22            
S8142 2023.01.01       N14W42            
S8143 2023.01.01       N21W15          
S8144 2023.01.01       N27W44            
S8145 2023.01.02       S25W58            
S8146 2023.01.02       S13E12            
S8147 2023.01.03       S16W49          
S8148 2023.01.03       N30W59          
S8149 2023.01.03       N33E02          
S8150 2023.01.03       N14E19          
S8151 2023.01.03       N11W55          
S8152 2023.01.03   1 1 S18E07 0003   AXX  
S8153 2023.01.04   1 1 S08E28 0003   AXX    
S8154 2023.01.04   5 3 S17E83 0600   CKO    
Total spot count: 36 127 68  
Sunspot number: 86 217 158  (total spot count + 10 * number of spotted regions)
Weighted SN: 61 162 103  (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): 95 119 126  

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 64.7 (+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
2023.01 149.6 (1)   11.7 (2A) / 90.8 (2B) / 138.0 (2C) (113.1 projected, +6.0) (11.3)
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.