Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 18, 2023 at 07:20 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 17. A weak soilar wind shock was observed at 21:07 UT at SOHO with a sudden increase in solar wind speed from 375 to 421 km/sec, likely the arrival of the January 14 CME. Solar wind speed at SOHO ranged between 347 and 465 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 221.7 - increasing 83.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 128.32). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 02211003 (planetary), 02212223 (Boulder), 01211105 (Andenes).

The background x-ray flux is at the class C1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 395) and in 12 active regions using 1K resolution (SN: 272) SDO/HMI images.

Region 13184 [S13W38] was mostly quiet and stable.
Region 13186 [N23W30] decayed slowly and quietly.
Region 13188 [S23W04] decayed slowly and quietly.
Region 13190 [S14E20] has a huge leader spot and major flare potential. A minor magnetic delta is at the southern edge of the leading penumbra.
Region 13191 [N11E12] decayed slowly and quietly.
Region 13192 [N18E23] was mostly unchanged and still has major flare potential.
Region 13193 [S22W56] decayed slowly and quietly.
Region 13194 [S23E11] decayed slowly and quietly.
New region 13195 [N20E05] emerged on January 13 and was numbered by SWPC 4 days later as the region developed slowly.

Spotted regions not observed (or interpreted differently) by SWPC:
S8178 [N12E26] developed slowly and quietly.
New region S8186 [S27E24] emerged with tiny spots.
New region S8187 [N12E59] emerged with tiny spots and is developing. C flares are possible.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C9.4/1F 00:13 N20E36 13192 GOES16  
C4.3 01:23 S14E35 13190 GOES16  
C3.6 01:58   13190 GOES16  
C2.2 02:57   S8178 GOES16  
C2.9 04:23   13184 GOES16  
C3.3 05:25 behind NW limb 13189 GOES16  
C2.0 07:36   13192 GOES16  
C2.3 08:01   13182 GOES16  
C2.7 09:23   13186 GOES16  
C2.6 12:06   13182 GOES16  
C2.8 12:21   13190 GOES16  
C2.7 13:17   13192 GOES16  
C2.1 14:11   13186 GOES16  
C3.6 15:18   13182 GOES16  
C2.2 20:36   S8178 GOES16  
C3.2 22:35   13188 GOES16 attributed to AR 13192 by SWPC
M1.8 23:29   13190 GOES16  

Coronal mass ejections (CMEs)

January 15-17: 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. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet to active geomagnetic conditions are expected on January 18 due to CME effects (from January 14 CME). Quiet to unsettled is likely on January 19-20 with a chance of active intervals 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
13182 2023.01.04
2023.01.05
1     S17W89 0000 AXX     rotated out of view
13184 2023.01.08
2023.01.08
5 16 9 S13W38 0190 HSX CSO

 

13187 2023.01.09
2023.01.10
      N16W80           location: N14W74
13186 2023.01.09
2023.01.10
11 29 12 N25W29 0430 EHO EHO

location N23W16

area: 0520

13188 2023.01.10
2023.01.12
7 12 6 S24W05 0010 BXO BXO location: S23W04

area: 0025

13189 2023.01.11
2023.01.13
      N23W87           location: N19W83
S8170 2023.01.12       N19W03           reversed polarities
13191 2023.01.12
2023.01.13
13 27 15 N11E08 0320 DSI DSO

location: N11E12

13192 2023.01.12
2023.01.13
13 49 32 N19E26 0380 FKI FAI beta-gamma

location: N18E23

13190 2023.01.12
2023.01.13
20 58 39 S14E20 0900 EKI EKI beta-gamma

area: 1100

13195 2023.01.13
2023.01.17
8 16 9 N11E04 0030 DRO DRI location: N20E05
S8178 2023.01.13   25 13 N12E26 0050   BXI  
13194 2023.01.13
2023.01.15
4 14 7 S23E10 0000 BXO BXO

location: S23E11

area: 0030

S8180 2023.01.13       S18W32            
S8181 2023.01.13       S22E04            
13193 2023.01.14
2023.01.15
3 10 5 S21W59 0030 CRO DRO

location: S22W56

S8184 2023.01.14       S27W28            
S8185 2023.01.16       S13E58          
S8186 2023.01.17   4 2 S27E24 0010   BXO    
S8187 2023.01.17   5 3 N12E59 0010   BXO    
Total spot count: 85 275 152  
Sunspot number: 185 395 272  (total spot count + 10 * number of spotted regions)
Weighted SN: 133 316 193  (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): 204 217 218  

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
2023.01 188.2 (1)   76.3 (2A) / 139.1 (2B) / 153.7 (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.