Solar Terrestrial Activity Report

Activity chart

Last major update issued on October 19, 2022 at 08:35 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 (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 on October 18. Solar wind speed at SOHO ranged between 473 and 602 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 113.9 - decreasing 23.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 116.86). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 10111222 (planetary), 11012311 (Boulder), 00010245 (Andenes).

The background x-ray flux is at the class B5 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 7 active regions using 2K resolution (SN: 107) and in 7 active regions using 1K resolution (SN: 86) SDO/HMI images.

Region 13121 [N23W11] reemerged with tiny spots.
Region 13122 [N26W63] decayed slowly and quietly.
Region 13124 [S34W66] decayed slowly producing several low level C flares. C1 flares: C1.6/1N @ 07:40, C1.9 @ 14:13, C1.0 @ 16:39, C1.2 @ 21:46 UT
Region 13125 [S25W12] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S7918 [S25W22] was quiet and stable.
S7934 [S10E29] decayed slowly and quietly.
S7935 [S23E47] was quiet and stable.

AR 13123 at the northwest limb was the likely source of a C1.0 flare at 03:29 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
           

Coronal mass ejections (CMEs)

October 16-18: 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 21-22.

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 geomagnetic conditions are likely on October 19-21 with a chance of unsettled intervals on October 20-21 if CH1106 becomes the dominant solar wind source.

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   8 1 S25W22 0010   BXO  
13121 2022.10.11
2022.10.13
  3 2 N24W11 0008   BXO  

location: N23W11

S7921 2022.10.11       S23W19           merged with AR S7918
S7922 2022.10.11       S16W22          
S7923 2022.10.12       N15W46            
13123 2022.10.13
2022.10.15
1     N28W93 0040 HSX DRO   rotated out of view
13122 2022.10.13
2022.10.15
1 1 1 N26W64 0010 AXX AXX area: 0002

location: N26W63

13125 2022.10.13
2022.10.17
3 8 4 S25W13 0010 BXO CRO area: 0020
13124 2022.10.14
2022.10.16
5 11 6 S34W68 0180 DSO DAO  
S7933 2022.10.14       S13W47            
S7934 2022.10.16   3 1 S10E29 0010   BXO  
S7935 2022.10.17   3 1 S23E49 0010   CRO  
Total spot count: 10 37 16  
Sunspot number: 50 107 86  (total spot count + 10 * number of spotted regions)
Weighted SN: 20 51 30  (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): 55 59 69  

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
2022.10 143.4 (1)   58.2 (2A) / 100.3 (2B) / 113.4 (2C) (108.3 projected, +3.1) (12.0)
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.