Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 8, 2023 at 08:00 UT. Minor update added at 13:15 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 quiet to unsettled on January 7. Solar wind speed at SOHO ranged between 373 and 477 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 178.9 - increasing 31.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 125.61). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.3). Three hour interval K indices: 13111321 (planetary), 02101321 (Boulder), 22200321 (Andenes).

The background x-ray flux is at the class C4 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 292) and in 8 active regions using 1K resolution (SN: 188) SDO/HMI images.

Region 13177 [S18W59] decayed slowly and quietly.
Region 13181 [S17W08] was quiet and stable. Note that SWPC includes AR S8155 in this region.
Region 13182 [S16E45] developed and has at least 3 magnetic delta configurations, the strongest one in a southern penumbra. Major flares, including X flares, are possible. C1 flares: C1.9 @ 03:55, C1.6 @ 04:51, C1.8 @ 06:04 UT
Region 13183 [S17W35] has a weak magnetic delta in an intermediate penumbra. Minor M class flares are possible. C1 flares: C1.5 @ 08:31 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S8133 [N17W38] was quiet and stable.
S8135 [N21W33] was quiet and stable.
S8155 [S21W02] developed further and is a compact region with small magnetic deltas in the northern and western part of the largest penumbra. An M class flare is possible.
S8158 [N23W77] developed early in the day, then decayed slowly.
S8159 [N21E28] was quiet and stable.

Another interesting region should soon rotate into view at the southeast limb. This region was the source of a C8.0 flare at 05:00 and a C7.0 flare at 05:47 UT on January 8. M flares are obviously possible.

Minor update added at 13:15 UT: AR S8160 began to rotate into view at 08:30 UT, then at S14E88. Only a few spots are visible so far. The region has produced 2 minor M class flares and several C flares today.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 00:34   13183 GOES16  
M1.6 00:52 S18E56 13182 GOES16  
C2.0 03:01   S8133 GOES16  
C2.3 05:01   13182 GOES16  
C2.2 09:05 northwest limb 13176? GOES16  
C2.0 09:32   13182 GOES16  
C6.9 11:09   13182 GOES16  
C2.2 12:38   13182 GOES16  
C2.4 13:30 southwest limb S8156 GOES16  
C8.7 16:54   13182 GOES16  
C4.5 18:25   13182 GOES16  
C5.1 18:34   13182 GOES16  
C3.6 19:26   13182 GOES16  
C3.1 20:51   13182 GOES16  
C4.7 21:05   13182 GOES16  
C4.9 22:05   13182 GOES16  
C3.6 22:38 S17E52 13182 GOES16  
C4.3 23:32   13182 GOES16  
C3.8 23:52   13182 GOES16  

Coronal mass ejections (CMEs)

January 5-7: 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. CH1124 rotated 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

Mostly quiet geomagnetic conditions are expected on January 8-10.

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
13177 2022.12.27
2022.12.28
3 5 2 S18W61 0020 AXX CRO location: S18W59
S8133 2022.12.29   12 3 N17W38 0100   CSO  
13180 2022.12.30 3     N18W37 0100 CSO       SWPC consider AR S8133 and S8135 to be one region
S8135 2022.12.30   3 2 N21W33 0080   CAO  
S8137 2022.12.30       S27W48          
13181 2022.12.31
2023.01.01
16 31 17 S21W07 0380 DKI DAO area: 0100

location: S17W08

SWPC considers this and AR S8155 as one region

S8143 2023.01.01       N21W54            
S8146 2023.01.02       S13W27            
S8149 2023.01.03       N33W37            
S8150 2023.01.03       N14W20            
13183 2023.01.03
2023.01.05
9 39 21 S17W36 0200 DSO ESI beta-delta
S8153 2023.01.04       S10W13            
13182 2023.01.04
2023.01.05
23 70 42 S17E46 0510 EKI EKC beta-gamma-delta

area: 0800

location: S16E45

S8155 2023.01.05   38 20 S21W03 0610   DKC beta-delta
S8157 2023.01.05       S02E14            
S8158 2023.01.06   2   N23W77 0004   AXX  
S8159 2023.01.06   2 1 N21E28 0004   AXX  
Total spot count: 54 202 108  
Sunspot number: 104 292 188  (total spot count + 10 * number of spotted regions)
Weighted SN: 84 245 134  (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): 114 161 150  

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
2023.01 157.7 (1)   21.6 (2A) / 95.6 (2B) / 137.6 (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.