Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 23, 2023 at 07:30 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 23. Solar wind speed at SOHO ranged between 371 and 547 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The January 20 CME was the likely source of a weak transient reaching SOHO at 03:09 UT. The Bz component of the interplanetary magnetic field was mostly northwards until noon resulting in only a weak disturbance.

Solar flux density measured at 20h UT on 2.8 GHz was 189.1 - increasing 30.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 130.05). 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: 12113212 (planetary), 0210322* (Boulder), 11003435 (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: 350) and in 16 active regions using 1K resolution (SN: 250) SDO/HMI images.

Region 13190 [S13W61] developed further in the new leading spot section which has emerged to the northwest of the largest penumbra. A major flare is possible.
Region 13191 [N11W71] decayed slowly and quietly.
Region 13192 [N17W58] decayed slowly and quietly.
Region 13195 [N22W80] reemerged with a few spots.
Region 13196 [N13W22] decayed slowly and quietly.
Region 13197 [N18W12] was quiet and stable.
Region 13198 [N26E04] decayed slowly and quietly.
Region 13200 [N22E48] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8178 [N10W54] decayed and could become spotless today.
S8194 [S24W67] decayed losing spots and area. The region was unstable and produced many C flares, the largest being a C6.5 event.
S8195 [N12E20] was quiet and stable.
S8196 [N18E20] was quiet and stable No spots have mature penumbra. Note that SWPC considers this and AR S8195 as one region.
S8200 [N22W08] developed in the southern section as new flux emerged.
S8205 [N15W10] was quiet and stable.
New region S8208 [N23E72] rotated into view with a mature spot.
New region S8209 [S29E54] was observed with a tiny spot in an old plage area.
New region S8210 [N25E33] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.7 00:32   13192 GOES16  
C5.2 01:06   S8194 GOES16  
C4.8 01:20   S8194 GOES16  
C2.6 04:00   13190 GOES16  
C2.3 05:15   S8196 GOES16  
C2.5 05:35   S8194 GOES16  
C2.8 05:56   S8194 GOES16  
C2.9 06:15   13191 GOES16  
C2.5 06:38   13190 GOES16  
C5.0 07:47 S13W50 13190 GOES16  
C3.9 07:56   S8194 GOES16  
C3.2 09:37 S25W61 S8194 GOES16  
C6.5 09:59   S8194 GOES16  
C4.1 10:19   S8194 GOES16  
C3.4 11:30 S13W55 13190 GOES16  
C2.1 12:41   13197 GOES16  
C2.8 14:06   S8194 GOES16  
C3.6 16:11   S8194 GOES16  
C3.2 17:12   S8194 GOES16  
C4.0 18:47   S8194 GOES16  
C4.4 19:22   S8194 GOES16  
C3.0 21:09   S8194 GOES16  
C2.3 22:39   S8194 GOES16  
C3.5 22:59   13190 GOES16  

Coronal mass ejections (CMEs)

January 21-23: 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 trans equatorial coronal hole (CH1126) rotated across the central meridian on January 21-22. A northern hemisphere coronal hole (CH1127) will be Earth facing on January 24.

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 expected on January 24-25 due to effects from CH1126. Quiet to unsettled is likely on January 26.

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
13188 2023.01.10
2023.01.12
      S23W79           location: S23W81
13191 2023.01.12
2023.01.13
2 6 3 N10W71 0040 CAO BXO

location: N11W71

area: 0015

13192 2023.01.12
2023.01.13
5 23 11 N15W56 0130 CAO CAO

location: N17W58

13190 2023.01.12
2023.01.13
14 24 15 S14W57 0720 EKC EKC beta-gamma-delta

area: 1240

location: S13W61

13195 2023.01.13
2023.01.17
  2 2 N21W78 0030   HRX   location: N22W80
S8178 2023.01.13   3 1 N10W54 0005   BXO  
13194 2023.01.13
2023.01.15
8     S25W70 0140 DAO      

location: S22W66

spotless, see AR S8194

S8185 2023.01.16       S13W20            
S8186 2023.01.17       S27W54            
13196 2023.01.17
2023.01.18
4 12 3 N13W22 0020 CSO BXO

 

13198 2023.01.18
2023.01.19
3 9 4 N27E03 0030 CSO CAO area: 0070

location: N26E04

13197 2023.01.18
2023.01.19
4 18 7 N24W10 0010 AXX DRO location: N18W12

SWPC position is way off

area: 0040

S8193 2023.01.18       N27W25          
S8194 2023.01.19   14 10 S24W67 0110   DAI  
S8195 2023.01.19   3 1 N12E20 0015   HRX  
S8196 2023.01.19   34 16 N18E20 0110   DRI beta-delta
S8198 2023.01.19       S14W22            
S8199 2023.01.19       S49W26            
S8200 2023.01.19   7 6 N22W08 0080   DRO  
13199 2023.01.20 12     N16E20 0080 DAI       SWPC considers ARs S8195 and S8196 to be one group
13200 2023.01.21
2023.01.22
2 11 4 N21E47 0070 CAO CAO

location: N22E48

S8203 2023.01.21       S24W08            
S8204 2023.01.21       N13E55          
S8205 2023.01.21   9 4 N15W10 0020   BXO reversed polarities
S8206 2023.01.21       S30W14            
S8207 2023.01.22       N01W15          
S8208 2023.01.23   1 1 N23E72 0090   HSX    
S8209 2023.01.23   1   S29E54 0001   AXX    
S8210 2023.01.23   3 2 N25E33 0010   BXO    
Total spot count: 54 180 90  
Sunspot number: 144 350 250  (total spot count + 10 * number of spotted regions)
Weighted SN: 99 230 140  (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): 158 193 200  

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
2023.01 193.9 (1)   109.5 (2A) / 147.6 (2B) / 172.2 (2C) (113.1 projected, +6.0) (9.4)
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.