Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 21, 2022 at 10:15 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 (October 6, 2022)
Solar cycle Solar cycles 23-25 (October 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (October 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 (October 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (October 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 quiet to unsettled on October 20. Solar wind speed at SOHO ranged between 382 and 483 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 115.8 - decreasing 30.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 117.07). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.3). Three hour interval K indices: 12111011 (planetary), 11211101 (Boulder), 21210003 (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 10 active regions using 2K resolution (SN: 156) and in 6 active regions using 1K resolution (SN: 85) SDO/HMI images.

Region 13122 [N27W85] rotated mostly out of view and became very active producing many C flares. C1 flares: C1.0 @ 06:20, C1.0 @ 12:39, C1.7 @ 15:46, C1.6 @ 20:28, C1.5 @ 23:07 UT
Region 13125 [S23W37] developed slowly and quietly after noon.
Region 13126 [S10E02] decayed significantly, particularly in the trailing spot section, and lost many spots.
New region 13127 [S23E24] emerged on October 17 and was numbered by SWPC 3 days later as slow development continued.

Spotted regions not observed (or interpreted differently) by SWPC:
S7918 [S23W48] was quiet and stable.
New region S7939 [S12E16] emerged with tiny spots.
New region S7940 [N11E23] emerged with a tiny spot.
New region S7941 [N30E14] emerged with tiny spots.
New region S7942 [S21E35] was observed with a tiny spot in an old plage area.
New region S7943 [S18E25] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 00:38 N25W78 13122 GOES16  
C5.3/1F 03:26 N25W78 13122 GOES16  
C2.0/1F 06:32 N26W84 13122 GOES16  
C2.9 06:46   13122 GOES16  
C2.0 13:28   13122 GOES16  
C2.2 15:13   13122 GOES16  
C2.7 15:24 N27W90 13122 GOES16  
C3.3 16:36   13122 GOES16  
C5.9 16:53   13122 GOES16  
C3.9 17:18   13122 GOES16  
C4.0 17:46   13122 GOES16  
C2.0 19:11   13122 GOES16  
C2.0 19:51   13122 GOES16  
C2.5 20:48   13122 GOES16  
C2.7 22:20   13122 GOES16  

Coronal mass ejections (CMEs)

October 18-20: 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 and poorly defined trans equatorial coronal hole (CH1106) closed on October 16 as it was rotating across the central meridian. A southern hemisphere coronal hole (CH1107) will likely become Earth facing on October 20-22. A recurrent northern hemisphere coronal hole (CH1108) will likely rotate into an Earth facing position on October 24.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is good. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are likely on October 21-23 with a chance of unsettled intervals on October 21 if CH1106 becomes the dominant solar wind source. October 24-25 could see quiet to active conditions due to effects from CH1107.

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
S7918 2022.10.10   5 2 S23W48 0008   AXX  
13121 2022.10.11
2022.10.13
      N24W38          

location: N23W37

S7922 2022.10.11       S16W48            
13122 2022.10.13
2022.10.15
  1   N27W85 0040   HRX  
13125 2022.10.13
2022.10.17
  7 3 S25W41 0015   BXO location: S23W37
13126 2022.10.16
2022.10.19
10 23 14 S11E02 0080 DSI DRI location: S10E02
13127 2022.10.17
2022.10.20
3 10 4 S23E23 0020 HAX CRO area: 0030
S7936 2022.10.19       S19W13          
S7937 2022.10.19       N26E25          
S7938 2022.10.20       N21W17          
S7939 2022.10.20   2 1 S12E16 0005   BXO    
S7940 2022.10.20   1 1 N11E23 0004   AXX    
S7941 2022.10.20   2   N30E14 0004   BXO    
S7942 2022.10.20   1   S21E35 0002   AXX    
S7943 2022.10.20   4   S18E25 0010   BXO    
Total spot count: 13 56 25  
Sunspot number: 33 156 85  (total spot count + 10 * number of spotted regions)
Weighted SN: 23 45 34  (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): 36 86 68  

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
2021.03 76.0 75.2 17.2 21.7 (+2.7) 10.17
2021.04 75.9 76.4 24.5 24.8 (+3.1) 8.40
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 (74.2 projected, +5.3) 11.79
2022.05 133.8 136.8 96.5 (80.6 projected, +6.4) 7.48
2022.06 116.1 119.8 70.3 (86.5 projected, +5.9) 8.20
2022.07 125.4 129.5 91.4 (93.7 projected, +7.2) 9.51
2022.08 114.2 117.1 75.4 (100.2 projected, +6.5) 10.92
2022.09 135.1 136.5 96.3 (105.2 projected, +5.0) 12.18
2022.10 140.5 (1)   60.9 (2A) / 94.4 (2B) / 112.4 (2C) (108.3 projected, +3.1) (11.3)
2022.11       (111.2 projected, +2.9)  
2022.12       (115.9 projected, +4.7)  
2023.01       (122.0 projected, +6.1)  
2023.02       (127.0 projected, +5.0)  
2023.03       (130.0 projected, +3.0)  
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.