Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 28, 2023 at 12:35 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 27 under the influence of effects from CH1126. Solar wind speed at SOHO ranged between 454 and 630 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 144.9 - decreasing 20.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 130.70). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.5). Three hour interval K indices: 10223322 (planetary), 01333322 (Boulder), 11023315 (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 15 active regions using 2K resolution (SN: 221) and in 9 active regions using 1K resolution (SN: 115) SDO/HMI images.

Region 13196 [N12W81] developed slowly and produced several flares. C1 flares: C1.5 @ 05:13, C1.8 @ 14:22, C1.4 @ 21:39 UT
Region 13197 [N18W71] decayed slowly and quietly.
Region 13198 [N26W48] was quiet and stable.
Region 13200 [N20W05] decayed slowly and quietly.
Region 13201 [N23E18] was quiet and stable.
Region 13203 [N17E06] was quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8195 [N10W31] developed slowly and quietly.
S8196 [N20W29] decayed further and could become spotless today.
S8209 [S29E05] was quiet and stable.
S8210 [N24W18] developed slowly and quietly.
S8214 [S18E68] was quiet and stable.
S8215 [S12E25] decayed slowly and quietly.
S8216 [S19E40] was quiet and stable.
New region S8218 [N19E66] rotated into view with tiny spots.
New region S8219 [N10E01] emerged with tiny spots.

AR 13192 behind the northwest limb was the likely source of a C1.7 flare at 00:58 and a C1.7 flare at 06:36 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.8 01:36 behind SE limb   GOES16  
C2.1 02:07 behind NW limb 13192? GOES16  
C5.2 07:48 SE limb   GOES16 LDE
C2.2 10:31   13196 GOES16  
C2.0 14:39   13196 GOES16 simultaneous flare in AR S8218
C2.0 16:27 SE limb   GOES16  

Coronal mass ejections (CMEs)

January 25-27: 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 northern hemisphere coronal hole (CH1127) was Earth facing on January 24. A recurrent southern hemisphere coronal hole (CH1128) will be Earth facing on January 28.

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 expected on January 28 due to effects from CH1127. Quiet conditions are likely on January 29-30.

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
3 5 2 N17W71 0020 CSO CRO

location: N12W81

area: 0040

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 2 1 N26W50 0020 HSX HSX

location: N26W48

area: 0040

13197 2023.01.18
2023.01.19
  2 1 N20W59 0008   AXX location: N18W71

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   4 2 N10W31 0010   CRO  
S8196 2023.01.19   2   N20W29 0005   AXX  
S8200 2023.01.19       N21W60          
13199 2023.01.20 1     N16W36 0010 AXX       SWPC considers ARs S8195 and S8196 to be one group
13200 2023.01.21
2023.01.22
2 11 6 N21W01 0010 BXO CRO

location: N20W05

area: 0030

S8204 2023.01.21       N13E03            
S8206 2023.01.21       S30W56            
13201 2023.01.23
2023.01.24
1 4 1 N25E17 0060 HSX CSO

location: N23E18

S8209 2023.01.23   4   S29E05 0004   BXO  
S8210 2023.01.23   4 3 N24W18 0020   CRO  
S8211 2023.01.24       S04W46            
13203 2023.01.24
2023.01.25
3 17 8 N16E03 0010 BXO CRI area: 0040

location: N17E06

13202 2023.01.25 3     N11W78 0040| CAO       SWPC has created a new region in the position of AR 13196
S8213 2023.01.25       S27W26            
S8214 2023.01.26   3 1 S18E68 0005   AXX  
S8215 2023.01.26   2   S12E25 0004   AXX  
S8216 2023.01.26   6   S19E40 0007   BXO  
S8217 2023.01.26       S41W21          
S8218 2023.01.27   2   N19E66 0002   AXX    
S8219 2023.01.27   3   N10E01 0005   AXX    
Total spot count: 14 71 25  
Sunspot number: 84 221 115  (total spot count + 10 * number of spotted regions)
Weighted SN: 34 96 50  (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): 92 122 92  

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
2023.01 189.1 (1)   124.2 (2A) / 142.6 (2B) / 172.3 (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.