Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 20, 2023 at 06:50 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 19. Solar wind speed at SOHO ranged between 349 and 501 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 226.1 - increasing 98.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 128.92). 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: 01332011 (planetary), 12323221 (Boulder), 01221013 (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 21 active regions using 2K resolution (SN: 539) and in 15 active regions using 1K resolution (SN: 300) SDO/HMI images.

Region 13184 [S13W64] was quiet and stable.
Region 13186 [N23W57] was mostly quiet and stable.
Region 13188 [S24W27] was quiet and stable.
Region 13190 [S14W07] was mostly unchanged and produced several C flares. The region still has major flare potential.
Region 13191 [N11W14] was quiet and stable.
Region 13192 [N18W04] decayed slowly and was mostly quiet. M class flares are possible.
Region 13194 [S22W14] decayed slowly and quietly.
Region 13195 [N21W21] developed slowly and quietly.
Region 13196 [N12E30] was unstable early in the day. The magnetic delta dissipated after noon and the region became much less active.
New region 13197 [N18E42] emerged on January 18 and was numbered the next day by SWPC.
New region 13198 [N27E57] rotated into view on January 18 with SWPC numbering the region the following day.

Spotted regions not observed (or interpreted differently) by SWPC:
S8178 [N13W01] developed slowly and produced a few C flares
S8193 [N22E27] was quiet and stable.
New region S8194 [S25W20] emerged with many spots southwest of AR 13194. C flares are possible.
New region S8195 [N12E75] rotated into view with small spots.
New region S8196 [N17E75] rotated into view with small spots.
New region S8197 [S11W12] emerged with tiny spots to the northwest of AR 13190.
New region S8198 [S14E30] was observed with tiny spots in an old plage area.
New region S8199 [S49E26] emerged with a tiny spot.
New region S8200 [N26E47] was observed with tiny spots in an old plage area.
New region S8201 [S16W38] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.8 00:58 N15E09 S8178 GOES16  
C3.6 03:55   13192 GOES16  
M1.1 04:03 N11E43 13196 GOES16  
C7.2 05:37 S17E26 13190 GOES16  
C2.7 06:40   13192 GOES16  
C2.6 08:48   13192 GOES16  
C2.4 08:58   13192 GOES16  
C2.9 09:50   13186 GOES16  
M1.7 10:12   13196 GOES16  
M1.0 10:27   13196 GOES16  
C4.0 11:02   13196 GOES16  
C2.6 12:33   13196 GOES16  
C2.3 14:20   13196 GOES16  
C5.5 15:41   13190 GOES16 simultaneous flare in AR S8178
C3.6 17:33   13186 GOES16  
C2.9 18:46   13190 GOES16  
C3.5 19:40   13196 GOES16  
C6.2 23:05 northeast limb   GOES16 incorrectly attributed to AR 13192 by SWPC

Coronal mass ejections (CMEs)

January 17-19: 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 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 unsettled geomagnetic conditions are likely on January 20-22 with a chance of active intervals on January 20 if a high speed stream from CH1125 arrives.

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 S12W65 0190 CSO CSO

location: S13W64

13186 2023.01.09
2023.01.10
4 12 5 N23W57 0320 EHO EHO

location N23W43

area: 0380

13188 2023.01.10
2023.01.12
  6   S23W18 0010 BXO BXO location: S24W27

SWPC lost track of this group and moved the position to near that of AR S8194

13191 2023.01.12
2023.01.13
8 28 11 N11W15 0220 DAO DAO

location: N11W14

13192 2023.01.12
2023.01.13
21 64 32 N16W01 0350 FKI FAI beta-gamma

location: N18W04

13190 2023.01.12
2023.01.13
13 71 33 S15W04 0860 EKI EKI beta-gamma

area: 1150

location: S14W07

13195 2023.01.13
2023.01.17
3 22 8 N21W24 0010 BXO DRI location: N21W21
S8178 2023.01.13   36 17 N13W01 0120   DRI  
13194 2023.01.13
2023.01.15
2 6 4 S23W18 0010 BXO BXO

location: S22W14

area: 0015

S8180 2023.01.13       S18W58            
S8181 2023.01.13       S22W22            
13193 2023.01.14
2023.01.15
      S22W84        

location: S22W81

S8184 2023.01.14       S27W54            
S8185 2023.01.16       S13E32            
S8186 2023.01.17       S27W02            
13196 2023.01.17
2023.01.18
3 18 8 N12E30 0020 DRO DRI beta-gamma

area: 0040

13198 2023.01.18
2023.01.19
6 12 8 N27E58 0030 CAO DRO area: 0050
13197 2023.01.18
2023.01.19
4 13 5 N24E46 0010 BXO BXO location: N18E42

area: 0025

S8193 2023.01.18   4   N22E27 0008   BXO  
S8194 2023.01.19   13 9 S25W20 0100   DAI    
S8195 2023.01.19   2 1 N12E75 0020   HRX    
S8196 2023.01.19   3 2 N18E75 0025   CRO    
S8197 2023.01.19   4 2 S11W12 0015   CRO    
S8198 2023.01.19   2   S14E30 0003   AXX    
S8199 2023.01.19   1   S49E26 0001   AXX    
S8200 2023.01.19   3   N26E47 0005   BXO    
S8201 2023.01.19   2   S16W38 0003   AXX    
Total spot count: 66 329 150  
Sunspot number: 166 539 300  (total spot count + 10 * number of spotted regions)
Weighted SN: 114 390 211  (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): 183 296 240  

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
2023.01 191.9 (1)   86.9 (2A) / 141.8 (2B) / 159.7 (2C) (113.1 projected, +6.0) (9.5)
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.