Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 21, 2022 at 10:05 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 on July 20. Solar wind speed at SOHO ranged between 372 and 498 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 132.2 - increasing 10.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 106.14). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.8). Three hour interval K indices: 22112112 (planetary), 32122221 (Boulder), 34213333 (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 15 active regions using 2K resolution (SN: 285) and in 10 active regions using 1K resolution (SN: 157) SDO/HMI images.

Region 13056 [S13W73] decayed slowly producing many C flares. C1 flares: C1.1 @ 05:23, C1.5 @ 09:02, C1.8 @ 09:15, C1.2 @ 16:57, C1.3 @ 22:37 UT
Region 13057 [N17W52] decayed slowly and quietly.
Region 13058 [N14W14] decayed slowly and was mostly quiet.
Region 13059 [S08W02] was quiet and stable.
Region 13060 [N11W06] decayed slowly and quietly. An interesting C5.6 flare was recorded at 01:11 UT on July 21 at N14W01. Some coronal dimming was observed, as was a very faint (at least partial halo) CME.
Region 13061 [N25W76] decayed slowly and quietly.
Region 13062 [S25E63] was unchanged and produced a long duration C4 event near the end of the day.
New region 13063 [N10E12] emerged on July 18 and was numbered 2 days later by SWPC.
New region 13064 [N08E30] emerged on July 19 with SWPC numbered the region the following day.

Spotted regions not observed (or interpreted differently) by SWPC:
S7712 [N28E26] reemerged with tiny spots.
S7713 [N17W04] was quiet and stable.
S7717 [N21W25] decayed slowly and quietly.
New region S7718 [S17E44] was observed with tiny spots in an old plage area.
New region S7719 [N40E05] emerged with a tiny spot at a high latitude location.
New region S7720 [N25W03] emerged with tiny spots.

A C1.9 flare was recorded at 00:15 UT from a location behind the southwest limb.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.3 02:15 N13E04 13058 GOES16  
C2.0 04:07   13056 GOES16  
C2.1 10:29   13056 GOES16  
C2.0 11:38   13056 GOES16  
C2.0 12:26   13056 GOES16  
C2.0 15:04   13056 GOES16  
C2.9 19:31   13056 GOES16  
C3.9 19:51   13056 GOES16  
C4.1 00:09 (on July 21, the event began at 23:01)   13062 GOES16 LDE, CME

Coronal mass ejections (CMEs)

July 21: A faint CME was observed after a C5.6 flare near center disk in AR 13060. The CME could reach Earth either late on July 24 or on July 25.
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.

Forecast

Quiet to minor storm conditions are possible on July 21-23 due to effects from CH1089 and possibly from the July 18 CME. Quiet to active is possible on July 24-25 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
7 14 5 S14W73 0040 CRO CRI

location: S13W73

13057 2022.07.10
2022.07.11
8 18 6 N17W48 0200 HSX CHO

location: N17W52

area: 0260

13058 2022.07.13
2022.07.14
5 10 7 N13W15 0030 BXO CRO

location: N14W14

13059 2022.07.14
2022.07.15
8 22 10 S08W00 0130 CSO CSO location: S08W02

area: 0160

13060 2022.07.14
2022.07.16
6 8 2 N13W06 0030 HRX CAO location: N11W06
S7704 2022.07.15       N33W54            
S7705 2022.07.15       N18W05            
S7706 2022.07.15       S06W34            
S7707 2022.07.16       S15W25            
13061 2022.07.16
2022.07.17
  1 1 N24W78 0003   AXX location: N24W76
13063 2022.07.18
2022.07.20
8 22 12 N10E09 0030 BXO DRI area: 0060

location: N10E12

S7710 2022.07.18       S15E43            
S7711 2022.07.18       N25W10            
S7712 2022.07.18   2   N28E26 0002   AXX    
S7713 2022.07.19   8 4 N17W04 0025   CRO  
13062 2022.07.19
2022.07.19
1 1 1 S26E60 0070 HSX HSX

location: S25E63

area: 0090

13064 2022.07.19
2022.07.20
6 20 9 N08E29 0030 BXO DRO  
S7717 2022.07.19   4   N21W25 0004   BXO  
S7718 2022.07.20   2   S17E44 0005   AXX    
S7719 2022.07.20   1   N40E05 0001   AXX    
S7720 2022.07.20   2   N25W03 0003   AXX    
Total spot count: 49 135 57  
Sunspot number: 129 285 157  (total spot count + 10 * number of spotted regions)
Weighted SN: 70 175 97  (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): 142 157 126  

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
2022.07 138.2 (1)   67.5 (2A) / 104.6 (2B) / 107.2 (2C) (95.3 projected, +7.2) (9.6)
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.