Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 31, 2023 at 08:45 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 (January 21, 2023) 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 30. Solar wind speed at SOHO ranged between 358 and 468 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels. weak effects from a high speed coronal hole stream were observed late in the day, probably related to CH1128.

Solar flux density measured at 20h UT on 2.8 GHz was 135.9 - decreasing 12.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 130.80). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.8). Three hour interval K indices: 10010013 (planetary), 10122222 (Boulder), 20000024 (Andenes).

The background x-ray flux is at the class B7 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 220) and in 10 active regions using 1K resolution (SN: 142) SDO/HMI images.

Region 13201 [N23W21] was quiet and stable.
Region 13203 [N18W33] was quiet and stable.
Region 13204 [N24W60] was mostly quiet and stable.
Region 13205 [S22W64] was mostly quiet and stable. C1 flares: C1.2 @ 01:01, C1.4 @ 06:42 UT.
Region 13206 [S21E48] has minor polarity intermixing at its center and produced a few flares. C1 flares: C1.4 @ 18:51, C1.4 @ 21:22 UT
New region 13207 [S12E74] rotated partly into view on January 29 and was numbered the next day by SWPC. Further C class flaring is likely. C1 flares: C1.5 @ 04:13, C1.7  @ 07:46, C1.3 @ 15:06. C1.4 @ 18:57, C1.2 @ 19:11, C1.3 @ 20:12 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S8215 [S12W16] was quiet and stable.
S8216 [S20W00] was quiet and stable.
S8224 [N16E02] was quiet and stable.
New region S8227 [N29E63] emerged with a few spots.
New region S8228 [S21W31] emerged with tiny spots.
New region S8229 [S17E20] was observed with tiny spots in an old plage area.
New region S8230 [S04E05] emerged with a tiny spot.

AR S8218 was the source of a C1.4 @ 14:01 and a C1.0 flare at 16:00 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.5 06:07 N20E37 S8218 GOES18  
C2.1 06:20   13207 GOES18  
C3.1 12:07   13207 GOES18  
C2.9 17:53   13207 GOES18  
C2.1 20:58 N23W41 13200 GOES18  
C2.0 23:55   13207 GOES18  

Coronal mass ejections (CMEs)

January 28-30: 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 (CH1128) was Earth facing on January 28-29.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet to unsettled conditions are likely on January 31-February 1 due to effects from CH1128. February 2-3 could see quiet conditions.

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
13198 2023.01.18
2023.01.19
      N26W89        

 

S8195 2023.01.19       N09W72          
S8196 2023.01.19       N19W80          
13199 2023.01.20       N16W77           SWPC considers ARs S8195 and S8196 to be one group
13200 2023.01.21
2023.01.22
      N21W42        

 

S8204 2023.01.21       N13W36            
13201 2023.01.23
2023.01.24
1 4 1 N24W22 0060 HSX CSO

location: N23W21

S8209 2023.01.23       S28W36            
13204 2023.01.23
2023.01.28
4 14 8 N25W59 0040 DAO DAI area: 0120

location: N24W60

13203 2023.01.24
2023.01.25
  2   N17W38 0002   AXX

location: N18W33

S8214 2023.01.26       S18E32          
S8215 2023.01.26   2   S12W16 0005   AXX  
S8216 2023.01.26   10 3 S20W00 0015   BXO  
S8218 2023.01.27       N19E28          
S8219 2023.01.27       N10W38            
13205 2023.01.28
2023.01.28
4 14 7 S22W62 0080 CAO CAI

area: 0140

location: S22W64

S8221 2023.01.28       N29W26            
S8222 2023.01.28       S32E09            
13206 2023.01.29
2023.01.29
5 23 13 S22E47 0010 BXO DRI

area: 0060

location: S21E48

S8224 2023.01.29   1 1 N16E02 0003   AXX  
13207 2023.01.29
2023.01.30
1 8 5 S13E71 0030 CAI ESI area: 0120

location: S12E74

S8227 2023.01.30   3 2 N29E63 0020   CRO    
S8228 2023.01.30   2   S21W31 0004   BXO    
S8229 2023.01.30   6 1 S17E20 0010   BXO    
S8230 2023.01.30   1 1 S04E05 0003   AXX    
Total spot count: 15 90 42  
Sunspot number: 65 220 142  (total spot count + 10 * number of spotted regions)
Weighted SN: 35 116 68  (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): 72 121 114  

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) 10.99
2023.01 183.9 (1)   131.3 (2A) / 135.7 (2B) / 171.0 (2C) (113.1 projected, +6.0) (8.8)
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.