Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 29, 2023 at 10:00 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 28 under the influence of effects from CH1127. Solar wind speed at SOHO ranged between 453 and 566 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 137.6 - decreasing 15.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 130.76). The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.5). Three hour interval K indices: 33213231 (planetary), 22223322 (Boulder), 54312254 (Andenes).

The background x-ray flux is at the class B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 15 active regions using 2K resolution (SN: 250) and in 11 active regions using 1K resolution (SN: 135) SDO/HMI images.

Region 13198 [N27W62] decayed slowly and quietly.
Region 13200 [N21W15] was mostly quiet and stable.
Region 13201 [N23E05] was quiet and stable.
Region 13203 [N17W07] was quiet and stable.
New region 13204 [N24W32] emerged on January 23, then decayed. New development was observed on January 27 and SWPC numbered the region the following day. C1 flares: C1.3 @ 01:04 UT
New region 13205 [S23W34] emerged with several spots and could produce C flares.

Spotted regions not observed (or interpreted differently) by SWPC:
S8195 [N09W44] decayed slowly and quietly.
S8196 [N19W51] was quiet and stable.
S8209 [S28W10] was quiet and stable.
S8214 [S19E58] was quiet and stable.
S8215 [S12E12] was quiet and stable.
S8216 [S23E29] was quiet and stable.
S8218 [N18E54] was quiet and stable.
New region S8221 [N29W00] emerged with a tiny spot.
New region S8222 [S32E35] was observed with tiny spots in an old plage area.

A C1.5 long duration event peaked at 14:11 UT and had its origin behind the southeast limb. A C1.3 flare at 04:16 was produced by AR 13196 at the northwest limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.9 08:31   13196 GOES16 LDE
C2.8 09:00   13196 GOES16  
C3.3 12:01   13200 GOES16  

Coronal mass ejections (CMEs)

January 26-28: 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 geomagnetic conditions are likely on January 29-30. Effects from CH1128 could cause quiet to active conditions on January 31 and February 1.

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
13196 2023.01.17
2023.01.18
      N17W84        

location: N12W94

rotated out of view

SWPC data has created confusion. They have moved AR 13196 to near the location of AR 13197, and created new AR 13202 in the location of AR 13196.

13198 2023.01.18
2023.01.19
1 3 1 N26W63 0020 HRX HRX

location: N27W6

13197 2023.01.18
2023.01.19
      N20W73         location: N18W84

AR 13197 is another victim in the confusion SWPC has created with their January 25 interpretation. The region has been moved to near the location of AR S8200 as the original AR 13196 has been moved to the location of AR 13197.

S8195 2023.01.19   1   N09W44 0002   AXX  
S8196 2023.01.19   5 3 N19W51 0010   BXO  
13199 2023.01.20       N16W50           SWPC considers ARs S8195 and S8196 to be one group
13200 2023.01.21
2023.01.22
1 22 6 N21W15 0010 BXO BXO

area: 0040

S8204 2023.01.21       N13W10            
13201 2023.01.23
2023.01.24
1 5 2 N23E04 0060 HSX CSO

location: N23E05

S8209 2023.01.23   2   S28W10 0003   AXX  
13204 2023.01.23
2023.01.28
3 24 10 N24W33 0010 BXO DRI area: 0080
13203 2023.01.24
2023.01.25
6 9 5 N17W10 0010 BXO BXO area: 0020

location: N17W07

S8213 2023.01.25       S27W39            
S8214 2023.01.26   3 1 S19E58 0005   BXO  
S8215 2023.01.26   4 1 S12E12 0008   AXX  
S8216 2023.01.26   8 2 S23E29 0012   BXO  
S8217 2023.01.26       S41W34            
S8218 2023.01.27   2   N18E54 0002   BXO  
S8219 2023.01.27       N10W12          
13205 2023.01.28
2023.01.28
4 8 4 S23W34 0010 BXO DRO   was AR S8220

area: 0050

S8221 2023.01.28   1   N29W00 0001   AXX    
S8222 2023.01.28   3   S32E35 0005   BXO    
Total spot count: 16 100 35  
Sunspot number: 76 250 135  (total spot count + 10 * number of spotted regions)
Weighted SN: 24 114 49  (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): 84 138 108  

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
2023.01 187.3 (1)   126.6 (2A) / 140.2 (2B) / 171.6 (2C) (113.1 projected, +6.0) (9.0)
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.