Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 12, 2023 at 04:50 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 11 under the influence of weak coronal hole effects. Solar wind speed at SOHO ranged between 375 and 451 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 195.1 - increasing 29.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 126.55). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.2). Three hour interval K indices: 23221222 (planetary), 23222332 (Boulder), 32211335 (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 10 active regions using 2K resolution (SN: 350) and in 9 active regions using 1K resolution (SN: 224) SDO/HMI images.

Region 13181 [S16W60] decayed slowly. There is still some polarity intermixing. C and M class flares are possible.
Region 13182 [S17W09] decayed losing spots and area.
Region 13184 [S13E39] still has a magnetic delta in the trailing part of the leading spot section. M class flaring is still likely.
Region 13185 [N19W27] developed further and currently has no polarity intermixing.
Region 13186 [N23E49] developed gaining area and spots. The magnetic delta in the penumbra disappeared and there was a significant reduction in flare frequency after noon.
Region 13187 [N13E07] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S8155 [S22W52] decayed slowly with the main penumbra fragmenting into smaller penumbrae.
S8167 [S17W69] decayed slowly and quietly.
S8168 [S23E75] was quiet and stable.
New region S8169 [N19W03] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
M2.4/1F 00:59 N23E66 13186 GOES16 moderate type IV radio sweep
M1.0 01:21   13182 GOES16  
M5.6/1B 01:56   13184 GOES16 weak type II radio sweep
C6.8 03:38 S16E21 13182 GOES16 weak type IV radio sweep
C3.6 04:25   13185 GOES16  
C3.8 05:18   13186 GOES16  
M1.3 06:09 S16W26 13181 GOES16  
C4.3 07:11   13186 GOES16  
C4.2 07:46   13186 GOES16  
C2.2 10:02   13181 GOES16  
M3.1 10:40 N23E66 13186 GOES16 partial halo CME
C2.2 13:12   13186 GOES16  
C2.8 14:05   13186 GOES16  
C4.6 15:31   13181 GOES16  
C3.6 17:57   13184 GOES16  
C8.0/1N 21:00 S14E38 13184 GOES16 partial halo CME, weak type II radio sweep

Coronal mass ejections (CMEs)

January 9-10: No obviously Earth directed CMEs were observed in available LASCO imagery.
January 11: AR 13184 was the source a C8 flare at 21:00 UT. A partial halo CME was observed after this event with the main ejecta off the southeast limb. Effects from this CME could reach Earth on January 14 or 15. Another partial halo CME was observed after an M3 flare in AR 13186 at 08:33 UT. There's minor chance that this CME could reach Earth on January 14.

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]

No obvious coronal holes are currently in or near Earth facing positions.

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 12-13. Should one or both of the CMEs observed on January 11 reach Earth, unsettled to major storm conditions will be possible on January 14-15.

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
13181 2022.12.31
2023.01.01
38 20 11 S18W61 0450 EKC DAI area: 0200

beta-gamma

location: S16W60

SWPC considers this, ARs S8155 and S8167 as one region

13182 2023.01.04
2023.01.05
49 79 46 S17W08 0650 EHI EKI beta-gamma

location: S17W09

13183 2023.01.03
2023.01.05
2     S16W91 0050 HSX     rotated out of view
S8155 2023.01.05   28 17 S22W53 0370   DAI beta-gamma
S8157 2023.01.05       S02W38            
13185 2023.01.06
2023.01.09
12 35 16 N20W27 0030 DRO DAI

area: 0150

location: N19W27

13184 2023.01.08
2023.01.08
13 34 15 S13E40 0730 EKC EHC beta-gamma-delta

area: 0550

S8161 2023.01.08       S17W28            
S8162 2023.01.08       S31W22            
13187 2023.01.09
2023.01.10
  3   N13E03 0003   AXX location: N13E07
13186 2023.01.09
2023.01.10
9 28 22 N24E51 0150 DAI EKI beta-gamma

location: N23E49

area: 0490

S8165 2023.01.09       S07W13          
S8167 2023.01.10   4 2 S17W69 0010   BXO  
S8168 2023.01.10   4 2 S23E75 0060   DSO  
S8169 2023.01.11   5 3 N19W03 0020   CRO    
Total spot count: 123 240 134  
Sunspot number: 183 350 224  (total spot count + 10 * number of spotted regions)
Weighted SN: 166 293 186  (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): 201 193 179  

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
2023.01 169.7 (1)   42.4 (2A) / 119.5 (2B) / 140.2 (2C) (113.1 projected, +6.0) (7.8)
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.