Solar Terrestrial Activity Report

Activity chart

Last major update issued on May 23, 2022 at 08:10 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 (May 1, 2022)
Solar cycle Solar cycles 23-25 (May 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (May 1, 2022) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (June 1, 2020) POES auroral activity level October 2009 - December 2012]
  Comparison of cycles 21-25 (May 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (May 1, 2022) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (April 10, 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 active on May 22 under the influence of a high speed stream associated with CH1079. The high latitude magnetometer at Andenes recorded quiet to severe storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 164.7 - increasing 8.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 98.72). The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.1). Three hour interval K indices: 43322221 (planetary), 33433331 (Boulder), 67335332 (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 13 active regions using 2K resolution (SN: 342) and in 10 active regions using 1K resolution (SN: 194) SDO/HMI images.

Region 13010 [S16W57] decayed slowly and quietly.
Region 13011 [N19W58] was mostly quiet and stable. C1 flares: C1.7 @ 19:13 UT
Region 13014 [N22W33] decayed slowly and produced a few small C flares. The region is still a large and complex spot group with multiple magnetic deltas. An X class flare is possible. C1 flares: C1.8 @ 01:26, C1.6 @ 22:11, C1.9 @ 22:30 UT
Region 13015 [N15W40] decayed slowly and quietly.
Region 13016 [S18W07] decayed slowly and quietly.
Region 13017 [N12W15] developed significantly in the leading spot section and has polarity intermixing. M class flaring is possible. C1 flares: C1.8 @ 10:12 UT
Region 13019 [N14E33] was mostly quiet and stable. C1 flares: C1.9 @ 13:54 UT
New region 13020 [S21E58] rotated into view on May 20 and was numbered by SWPC 2 days later.
New region 13021 [N12E70] rotated into view on May 21 and got its NOAA number the next day. Slow development was observed on May 22.

Spotted regions not observed (or interpreted differently) by SWPC:
S7580 [S16E36] was quiet and stable.
S7583 [N16W56] decayed slowly and quietly.
New region S7586 [S27W56] emerged with a tiny spot.
New region S7587 [N30E21] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.2 06:15   13014 GOES16  
C2.2 08:12   13021 GOES16  
C3.7 14:31 N11W12 13017 GOES16  
C2.4 15:43   13014 GOES16  
C4.6 23:40   13017 GOES16  

Coronal mass ejections (CMEs)

May 20-22: 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 southern hemisphere coronal hole (CH1080) will likely rotate across the central meridian on May 24-25.

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 to fair.

Forecast

Quiet geomagnetic conditions are likely on May 23-25.

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
13013 2022.05.11
2022.05.14
      S27W81           location: S26W75
13010 2022.05.11
2022.05.12
2 14 4 S18W58 0010 BXO CRO

location: S16W57

area: 0030

13011 2022.05.12
2022.05.13
1 8 4 N15W61 0010 AXX DRO

location: N19W58

area: 0040

13015 2022.05.13
2022.05.15
1 5   N14W39 0010 HSX AXX area: 0005
13014 2022.05.13
2022.05.15
18 60 29 N22W38 0890 EKC EKC beta-gamma-delta

location: N22W33

13016 2022.05.15
2022.05.16
4 14 8 S19W07 0020 CAO DRO area: 0040
13017 2022.05.15
2022.05.16
13 59 30 N14W14 0040 CRO EAI

beta-gamma

area: 0200

13018 2022.05.16
2022.05.17
      S11W16          
13019 2022.05.18
2022.05.19
4 25 10 N11E27 0020 CRO CRI area: 0050

location: N14E33

S7579 2022.05.19       N16E02          
S7580 2022.05.20   3   S16E36 0003   AXX  
13020 2022.05.20
2022.05.22
1 1 1 S20E58 0020 HSX HSX location: S21E58
S7582 2022.05.20       S30W37            
S7583 2022.05.21   5 3 N16W56 0015   BXO  
13021 2022.05.21
2022.05.22
4 5 4 N14E67 0020 CRO DRO area: 0040

location: N12E70

S7585 2022.05.21       N13E48          
S7586 2022.05.22   1 1 S27W56 0002   AXX    
S7587 2022.05.22   2   N30E21 0002   AXX    
Total spot count: 48 202 94  
Sunspot number: 138 332 194  (total spot count + 10 * number of spotted regions)
Weighted SN: 82 237 129  (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): 152 183 155  

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
 

2020.10

74.6 74.2 14.6 11.9 (+1.4) 6.13
2020.11 89.9 88.0 34.5 13.6 (+1.7) 4.77
2020.12 86.9 84.2 23.1 15.3 (+1.7) 4.72
2021.01 76.0 73.6 10.4 17.3 (+2.0) 4.39
2021.02 74.3 72.4 8.2 19.0 (+1.7) 9.50
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 31.3 (+3.7) 5.51
2021.08 77.7 79.7 22.0 35.3 (+4.0) 6.19
2021.09 87.0 88.2 51.3 40.0 (+4.7) 6.33
2021.10 88.9 88.3 37.4 45.0 (+5.0) 7.38
2021.11 86.2 84.4 34.8 (50.0 projected, +5.0) 9.83
2021.12 103.0 99.8 67.5 (55.8 projected, +5.8) 6.40
2022.01 103.8 100.5 54.0 (60.3 projected, +4.5) 8.92
2022.02 109.1 106.5 59.7 (65.2 projected, +4.9) 10.46
2022.03 117.0 115.8 78.5 (70.7 projected, +5.5) 10.20
2022.04 130.8 131.7 84.1 (75.9 projected, +5.2) 11.79
2022.05 139.7 (1)   70.7 (2A) / 99.7 (2B) / 114.0 (2C) (82.3 projected, +6.4) (6.7)
2022.06       (88.2 projected, +5.9)  
2022.07       (95.4 projected, +7.2)  
2022.08       (102.1 projected, +6.7)  
2022.09       (107.1 projected, +5.0)  
2022.10       (110.3 projected, +3.2)  

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.