Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 25, 2022 at 12:00 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 (December 4, 2022)
Solar cycle Solar cycles 23-25 (December 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (December 1, 2022) 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 (December 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (December 1, 2022) 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 unsettled to minor storm on December 24 under the influence of effects related to CH1121. Solar wind speed at SOHO ranged between 492 and 703 km/sec. The high latitude magnetometer at Andenes recorded unsettled to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 133.3. The Potsdam WDC planetary A index was 23 (STAR Ap - based on the mean of three hour interval ap indices: 23.3). Three hour interval K indices: 35443433 (planetary), 34543432 (Boulder), 46433545 (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 11 active regions using 2K resolution (SN: 280) and in 9 active regions using 1K resolution (SN: 176) SDO/HMI images.

Region 13168 [S15W62] was quiet and stable.
Region 13169 [N21W18] gained spots and area. A minor M class flare is possible.
Region 13170 [S20W11] decayed slowly and quietly.
Region 13171 [N24E01] was quiet and stable.
Region 13172 [S34E29] was quiet and stable.
Region 13173 [N26E37] developed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S8113 [N21W31] was quiet and stable.
New region S8118 [N30W48] emerged with a tiny spot.
New region S8119 [S20E68] rotated into view with a few spots.
New region S8120 [N20E31] emerged with tiny spots.
New region S8121 [S07E41] emerged with tiny spots.

Coronal mass ejections (CMEs)

December 22-23: No obviously Earth directed CMEs were observed in available LASCO imagery.
December 24: A filament eruption was observed near AR 13171 starting at approximately 00:38 UT. LASCO imagery displayed a partial halo CME that could reach Earth on December 27.

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 northern hemisphere coronal hole (CH1122) will rotate across the central meridian on December 25-27.

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 unsettled geomagnetic conditions are expected for December 25-26. On December 27-28 unsettled to minor storm conditions are possible due to CME effects. Effects from CH1122 could reach Earth on December 28 and cause quiet to minor storm conditions until December 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
13168 2022.12.13
2022.12.14
1 1 1 S15W65 0060 HSX HSX area: 0090

location: S15W62

13169 2022.12.16
2022.12.17
25 95 50 N20W21 0260 FSI FAC

beta-gamma

area: 0620

location: N21W18

13170 2022.12.17
2022.12.17
  11 3 S19W16 0020   BXO

location: S20W11

S8102 2022.12.17       N06W44           reversed polarities
13171 2022.12.18
2022.12.19
6 17 10 N23W01 0140 CKO CAO location: N24E01
S8107 2022.12.18       S15W26            
13174 2022.12.19
2022.12.22
      N23E11           region should be deleted, spots were within the trailing polarity of AR 13171
S8109 2022.12.19       N09W24            
13172 2022.12.20
2022.12.21
2 20 9 S34E24 0030 HSX DRI location: S34E29
S8113 2022.12.20   6 3 N21W31 0010   AXX  
13173 2022.12.22
2022.12.22
1 9 5 N25E50 0080 HSX CAO

 

S8115 2022.12.22       S03E04            
S8116 2022.12.23       S17W09          
S8117 2022.12.23       S22W08          
S8119 2022.12.24   6 4 S20E68 0020   DRO    
S8120 2022.12.24   2 1 N20E31 0004   AXX    
S8121 2022.12.24   2   S07E31 0004   BXO    
Total spot count: 35 170 86  
Sunspot number: 85 280 176  (total spot count + 10 * number of spotted regions)
Weighted SN: 65 196 112  (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): 94 154 141  

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
2021.05 75.3 77.1 21.2 25.8 (+1.0) 6.50
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 64.8 (+4.7) 10.46
2022.03 117.0 115.8 78.6 68.9 (+4.1) 10.20
2022.04 130.8 131.7 84.0 73.1 (+4.2) 11.79
2022.05 133.8 136.8 96.5 77.3 (+4.2) 7.48
2022.06 116.1 119.8 70.3 (80.7 projected, +3.6) 8.20
2022.07 125.4 129.5 91.4 (85.7 projected, +5.0) 9.51
2022.08 114.2 117.1 75.4 (91.4 projected, +5.7) 10.92
2022.09 135.1 136.5 96.3 (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
2022.12 145.1 (1)   90.5 (2A) / 113.1 (2B) / 123.4 (2C) (107.1 projected, +4.8) (9.5)
2023.01       (113.1 projected, +6.0)  
2023.02       (118.1 projected, +5.0)  
2023.03       (121.2 projected, +3.1)  
2023.04       (126.6 projected, +5.4)  
2023.05       (132.4 projected, +5.8)  
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.