Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 21, 2023 at 11:05 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 (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 on January 20. Solar wind speed at SOHO ranged between 350 and 541 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels. A coronal high speed stream, possibly associated with CH1125 began to influence the field early on January 21.

Solar flux density measured at 20h UT on 2.8 GHz was 217.5 - increasing 84.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 129.23). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.9). Three hour interval K indices: 11012211 (planetary), 11112322 (Boulder), 31001422 (Andenes).

The background x-ray flux is at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 17 active regions using 2K resolution (SN: 430) and in 14 active regions using 1K resolution (SN: 276) SDO/HMI images.

Region 13184 [S13W78] was mostly quiet and stable.
Region 13186 [N22W72] decayed slowly and quietly.
Region 13188 [S23W42] was quiet and stable.
Region 13190 [S14W20] lost spots and area in the trailing spot section. The region was the source of several C flares and still has major flare potential.
Region 13191 [N11W28] was quiet and stable.
Region 13192 [N18W17] decayed slowly in the trailing spot section and redeveloped a small magnetic delta in the leading spot section. M class flares are possible.
Region 13195 [N21W32] decayed slowly and quietly.
Region 13196 [N12E17] decayed slowly and quietly.
Region 13197 [N17E29] developed slowly and quietly.
Region 13198 [N26E42] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S8178 [N13W14] decayed slowly and quietly.
S8193 [N25E12] was quiet and stable.
S8194 [S25W32] was mostly unchanged and quiet.
S8195 [N12E60] was quiet and stable.
S8196 [N17E61] developed slowly and quietly. Note that SWPC considers this and AR S8195 as one region.
S8198 [S14E17] was quiet and stable.
S8200 [N24E33] was quiet and stable.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C6.7 01:52 S17W02 13190 GOES16  
C2.6 02:54   13190 GOES16  
C2.5 03:39   13196 GOES16  
C4.0 05:44   13190 GOES16 LDE
C4.5 06:32   S8194 GOES16  
C2.0 11:48   S8194 GOES16  
C4.8 12:57   13190 GOES16  
C5.3 14:07   13190 GOES16  
C3.4 16:39   13192 GOES16  
C4.0 16:59   13192 GOES16  
C3.1 17:43   13190 GOES16  
C2.7 18:39   13190 GOES16  
C2.9 20:21   13184 GOES16  
C7.3 22:47 N10W14 S8178 GOES16  
C2.4 23:12   13190 GOES16  
C3.0 23:46   13184 GOES16  
C3.0 00:00   13186 GOES16  

Coronal mass ejections (CMEs)

January 18-19: No obviously Earth directed CMEs were observed in available LASCO imagery.
January 20: A large filament eruption began near noon in the southwest quadrant and apparently triggered a C5 flare in AR 13190 at 14:07 UT. A partial halo CME was observed in LASCO imagery. There is a slight chance of CME effects at Earth on January 23 and 24.

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 small and poorly defined trans equatorial coronal hole (CH1125) was Earth facing on January 16. A southern hemisphere coronal hole (CH1126) will likely rotate across the central meridian on January 21.

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 to active geomagnetic conditions are likely on January 21 due to a high speed coronal hole stream. Quiet to unsettled is expected for January 22-24 with a chance of active and minor storm intervals on January 23-24 should the January 20 CME arrive.

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
13184 2023.01.08
2023.01.08
2 7 5 S12W80 0090 HSX CSO

location: S13W78

area: 0180

13186 2023.01.09
2023.01.10
4 3 2 N24W67 0230 ESO CHO

location N22W72

area: 0350

13188 2023.01.10
2023.01.12
  5 1 S23W37 0008   BXO location: S23W42
13191 2023.01.12
2023.01.13
8 18 11 N12W30 0220 DAO DAO

location: N11W28

area: 0170

13192 2023.01.12
2023.01.13
32 55 29 N16W15 0330 FKI EAI beta-gamma-delta

location: N18W17

13190 2023.01.12
2023.01.13
14 54 32 S15W18 0710 EKI EKI beta-gamma

area: 1070

location: S14W20

13195 2023.01.13
2023.01.17
4 6 2 N21W36 0010 BXO BXO location: N21W32
S8178 2023.01.13   28 15 N13W14 0050   CRI  
13194 2023.01.13
2023.01.15
4     S24W31 0040 CAO    

location: S22W27

spotless, SWPC has moved the group to AR S8194

S8185 2023.01.16       S13E19            
S8186 2023.01.17       S27W15            
13196 2023.01.17
2023.01.18
4 14 6 N12E16 0010 BXO DRO

area: 0025

13198 2023.01.18
2023.01.19
6 10 4 N27E45 0030 CAO CAO area: 0110

location: N26E42

13197 2023.01.18
2023.01.19
4 15 8 N24E32 0010 BXO CRI location: N17E29

SWPC position is way off

area: 0035

S8193 2023.01.18   4   N25E12 0007   AXX  
S8194 2023.01.19   19 12 S25W32 0100   DAI  
S8195 2023.01.19   1 1 N12E60 0020   HRX  
S8196 2023.01.19   17 8 N17E61 0080   DRI  
S8197 2023.01.19       S11W25          
S8198 2023.01.19   1   S14E17 0001   AXX  
S8199 2023.01.19       S49E13          
S8200 2023.01.19   3   N24E33 0004   BXO  
S8201 2023.01.19       S16W51          
13199 2023.01.20 5     N15E61 0040   CAO     SWPC apparently considers ARs S8195 and S8196 to be one group
Total spot count: 87 260 136  
Sunspot number: 197 430 276  (total spot count + 10 * number of spotted regions)
Weighted SN: 137 325 201  (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): 217 237 221  

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) 11.13
2023.01 193.1 (1)   93.1 (2A) / 144.6 (2B) / 163.6 (2C) (113.1 projected, +6.0) (9.2)
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.