Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 22, 2022 at 09:50 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 (July 6, 2022)
Solar cycle Solar cycles 23-25 (July 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (July 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 (July 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (July 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 minor storm on July 21. Solar wind speed at SOHO ranged between 358 and 483 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. A high speed stream from CH1089 gradually became the dominant solar wind source after 04 UT and was the source of the geomagnetic disturbance during the latter half of the day.

Solar flux density measured at 20h UT on 2.8 GHz was 121.7 - increasing 6.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 106.22). The Potsdam WDC planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 19.4). Three hour interval K indices: 21133553 (planetary), 21243544 (Boulder), 31133455 (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 11 active regions using 2K resolution (SN: 206) and in 10 active regions using 1K resolution (SN: 147) SDO/HMI images.

Region 13057 [N17W64] decayed slowly producing a few C flares. C1 flare: C1.3 @ 19:58 UT
Region 13058 [N14W26] decayed slowly and quietly.
Region 13059 [S08W14] decayed slowly and quietly.
Region 13060 [N11W20] gained negative polarity spots ahead of the positive polarity leader spot.
Region 13062 [S25E50] was quiet and stable.
Region 13063 [N11W02] decayed slowly and quietly.
Region 13064 [N08E17] developed slowly and was mostly quiet. C1 flare: C1.5 @ 15:22, C1.6 @ 22:23 UT
New region 13065 [S19E15] emerged with a few spots.

Spotted regions not observed (or interpreted differently) by SWPC:
S7712 [N28E13] was quiet and stable.
S7713 [N17W19] decayed slowly and quietly.
S7718 [S16E30] was quiet and stable.

AR 13056 was the source of the following C1 flares: C1.6 @ 05:06, C1.3 @ 06:15, C1.5 @ 08:51 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.2 00:43   13057 GOES16  
C5.6 01:11 N14W01 13060 GOES16 halo CME, moderate type II and weak IV radio sweeps
C2.2 03:18   13057 GOES16  
C3.1 11:49 southwest limb 13056 GOES16 SWPC incorrectly attributed this to AR 13064. There was a simultaneous, smaller event in that AR.
C2.6 12:56   13056 GOES16  
C6.1 23:46 southwest limb 13056 GOES16  

Coronal mass ejections (CMEs)

July 21: A faint halo CME was observed after a C5.6 flare near center disk in AR 13060. The CME could reach Earth on July 23.
July 19-20
: No obviously Earth directed CMEs were observed in available LASCO imagery.
July 18: A partial halo CME was observed after a filament eruption in the southern hemisphere after 20h UT. The filament eruption triggered activity in AR 13056 and a partial halo CME was observed late in the day. While the bulk of the CME is not headed towards Earth, there is a chance of weak effects on July 22.

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 large trans equatorial coronal hole (CH1089) was Earth facing on July 18-20.

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 to active conditions are possible on July 22 due to effects from CH1089 and possibly from the July 18 CME. Quiet to major storm conditions are possible on July 23-24 if the July 21 CME reaches Earth.

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 midnigh4t Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlays
Comment
SWPC/
USAF
Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
13056 2022.07.09
2022.07.10
1     S14W87 0020 HRX    

rotated out of view

13057 2022.07.10
2022.07.11
5 7 6 N17W62 0160 CSO CSO

location: N17W64

area: 0250

13058 2022.07.13
2022.07.14
2 9 2 N14W29 0020 AXX BXO

location: N14W26

13059 2022.07.14
2022.07.15
3 12 8 S08W14 0100 HSX CSO

area: 0150

13060 2022.07.14
2022.07.16
4 15 7 N14W20 0030 HRX DRI location: N11W20

area: 0050

S7705 2022.07.15       N18W18            
S7706 2022.07.15       S06W47            
S7707 2022.07.16       S15W38            
13063 2022.07.18
2022.07.20
7 14 7 N11W03 0030 BXO DRO

 

S7710 2022.07.18       S15E30            
S7711 2022.07.18       N25W23            
S7712 2022.07.18   2 1 N28E13 0004   AXX  
S7713 2022.07.19   2 1 N17W19 0005   AXX  
13062 2022.07.19
2022.07.19
1 3 1 S25E48 0120 HSX CSO

location: S25E50

13064 2022.07.19
2022.07.20
8 25 11 N08E16 0040 CSO DAI beta-gamma
S7717 2022.07.19       N21W38          
S7718 2022.07.20   3   S16E30 0003   AXX  
S7719 2022.07.20       N40W08          
S7720 2022.07.20       N25W16          
13065 2022.07.21
2022.07.21
3 4 3 S19E15 0010 BXO CRO   was AR S7721
Total spot count: 34 96 47  
Sunspot number: 124 206 147  (total spot count + 10 * number of spotted regions)
Weighted SN: 60 125 76  (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): 136 113 118  

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
2020.12 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 50.6 (+5.6) 9.83
2021.12 103.0 99.8 67.5 55.7 (+5.1) 6.40
2022.01 103.8 100.5 54.0 (59.5 projected, +3.8) 8.92
2022.02 109.1 106.5 59.7 (65.1 projected, +5.6) 10.46
2022.03 117.0 115.8 78.5 (70.5 projected, +5.4) 10.20
2022.04 130.8 131.7 84.1 (75.7 projected, +5.2) 11.79
2022.05 133.8 136.8 96.5 (82.2 projected, +6.5) 7.48
2022.06 116.1 119.8 70.6 (88.1 projected, +5.9) 8.20
2022.07 137.4 (1)   71.5 (2A) / 105.5 (2B) / 107.0 (2C) (95.3 projected, +7.2) (10.1)
2022.08       (101.9 projected, +6.6)  
2022.09       (106.9 projected, +5.0)  
2022.10       (110.1 projected, +3.2)  
2022.11       (112.9 projected, +2.8)  
2022.12       (117.7 projected, +4.8)  
2023.11       (141.4 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.