Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 20, 2022 at 10:10 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 (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 19 due to CME effects. Solar wind speed at SOHO ranged between 407 and 541 km/sec. The high latitude magnetometer at Andenes recorded unsettled to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 144.1 - increasing 15.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 106.01). The Potsdam WDC planetary A index was 26 (STAR Ap - based on the mean of three hour interval ap indices: 25.6). Three hour interval K indices: 24445444 (planetary), 34434323 (Boulder), 33445565 (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 11 active regions using 2K resolution (SN: 255) and in 11 active regions using 1K resolution (SN: 185) SDO/HMI images.

Region 13056 [S14W58] decayed further and produced several low level C flares. C1 flares: C1.4 @ 07:35, C1.3 @ 08:12, C1.5 @ 09:37, C1.3 @ 11:12, C1.5 @ 13:30, C1.4 @ 16:16, C1.3 @ 21:20, C1.3 @ 22:17, C1.8 @ 22:54 UT
Region 13057 [N17W38] decayed slowly as many tiny spots disappeared. C1 flares: C1.6 @ 17:23 UT
Region 13058 [N14E00] decayed slowly and was mostly quiet. Small opposite polarity umbrae are narrowly separated in the trailing spot section. C1 flares: C1.3 @ 01:09, C1.4 @ 12:34 UT
Region 13059 [S08E12] was quiet and mostly stable. C1 flares: C1.3 @ 19:39 UT
Region 13060 [N11E08] gained spots and was quiet.
Region 13061 [N24W62] lost the leader spots and was mostly quiet.
New region 13062 [S25E76] rotated into view with a mature spot.

Spotted regions not observed (or interpreted differently) by SWPC:
S7709 [N10E25] developed further and has many small spots.
New region S7713 [N18E09] emerged with a few spots.
New region S7716 [N08E45] emerged with several spots.
New region S7717 [N20W13] emerged with tiny spots.

A C1.6 flare was recorded at 02:16 UT from a location behind the southwest limb, as was a C1.3 flare at 08:54 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.2 02:52   13057 GOES16  
C2.3 04:29   13058 GOES16 incorrectly attributed to AR 13061 by SWPC

Coronal mass ejections (CMEs)

July 17, 19: 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 likely on July 20 due to CME effects. Quiet to minor storm conditions are possible on July 21-23 due to effects from CH1089 and possibly from the July 18 CME.

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
11 22 11 S16W57 0080 DRI DRI

location: S14W58

13057 2022.07.10
2022.07.11
11 23 12 N15W37 0190 ESO EKO

location: N17W38

area: 0280

13058 2022.07.13
2022.07.14
7 16 10 N13W00 0070 DRO DRI

location: N14E00

S7701 2022.07.13       N20W55            
13059 2022.07.14
2022.07.15
6 17 9 S07E15 0130 CSO DAO location: S08E12

area: 0180

13060 2022.07.14
2022.07.16
6 13 8 N14E07 0030 HSX CAO location: N11E08
S7704 2022.07.15       N33W41            
S7705 2022.07.15       N18E08            
S7706 2022.07.15       S06W21            
S7707 2022.07.16       S15W12          
13061 2022.07.16
2022.07.17
2 5 4 N22W65 0010 AXX HRX location: N24W62

area: 0020

S7709 2022.07.18   20 9 N10E25 0070   DRI  
S7710 2022.07.18       S15E56            
S7711 2022.07.18       N25E03          
S7712 2022.07.18       N29E35          
S7713 2022.07.19   8 3 N18E09 0020   BXO    
13062 2022.07.19
2022.07.19
1 1 1 S23E72 0060 HSX HSX   was AR S7714

location: S25E75

area: 0090

S7716 2022.07.19   14 7 N08E45 0070   DRI    
S7717 2022.07.19   6 1 N20W13 0010   BXO    
Total spot count: 44 145 75  
Sunspot number: 114 255 185  (total spot count + 10 * number of spotted regions)
Weighted SN: 70 185 115  (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): 125 140 148  

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
2022.07 138.5 (1)   63.3 (2A) / 103.3 (2B) / 107.1 (2C) (95.3 projected, +7.2) (9.8)
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.