Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 26, 2022 at 08:00 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 unsettled on July 25. Solar wind speed at SOHO ranged between 372 and 495 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels. A disturbance was observed arriving at DSCOVR with fairly sudden increases in solar wind speed, density and temperature around 02:38 UT on July 26.

Solar flux density measured at 20h UT on 2.8 GHz was 102.3 - increasing 6.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 106.48). 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: 32011112 (planetary), 32112312 (Boulder), 43011223 (Andenes).

The background x-ray flux is at the class B2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 189) and in 10 active regions using 1K resolution (SN: 132) SDO/HMI images.

Region 13059 [S08W68] was quiet and stable.
Region 13060 [N11W76] decayed slowly and quietly.
Region 13062 [S25W01] gained a few spots and was mostly quiet.
Region 13063 [N11W58] decayed slowly and quietly.
Region 13064 [N09W43] decayed slowly and quietly.
Region 13065 [S19W39] was quiet and stable.
New region 13066 [S15E16] emerged on July 24 with SWPC numbering the group the next day.

Spotted regions not observed (or interpreted differently) by SWPC:
S7712 [N28W31] reemerged with a tiny spot.
S7722 [S23W20] was quiet and stable.
New region S7728 [N24E51] emerged with tiny spots.
New region S7729 [N20E78] rotated into view. C1 flare: C1.4 @ 08:33 UT
New region S7730 [N28E42] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
           

Coronal mass ejections (CMEs)

July 22-24: 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 small northern hemisphere coronal hole (CH1090) could become Earth facing on July 26-27.

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 active conditions are possible on July 26-27. A high speed stream from CH1090 could cause quiet to active conditions on July 28-29.

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
13058 2022.07.13
2022.07.14
      N14W83          

location: N14W77

13059 2022.07.14
2022.07.15
1 2 1 S08W70 0080 HSX CSO

location: S08W68

13060 2022.07.14
2022.07.16
5 4 2 N12W75 0020 CRO AXX

area: 0012

location: N11W76

S7705 2022.07.15       N18W57            
13063 2022.07.18
2022.07.20
1 2 2 N11W59 0000 AXX BXO area: 0008
S7710 2022.07.18       S15W22            
S7712 2022.07.18   1   N28W31 0001   AXX    
13062 2022.07.19
2022.07.19
4 9 4 S25W03 0100 CSO CSO

area: 0130

13064 2022.07.19
2022.07.20
4 6 3 N09W44 0020 HRX CRO

area: 0050

location: N09W43

S7718 2022.07.20       S15W22            
13065 2022.07.21
2022.07.21
10 22 10 S19W40 0030 CRO DRI area: 0050
S7722 2022.07.22   3 1 S23W20 0005   BXO  
S7723 2022.07.23       S10W08            
S7724 2022.07.23       N18E03            
13066 2022.07.24
2022.07.25
5 14 7 S16E15 0030 CRO CRI location: S15E16

area: 0060

S7727 2022.07.24       S17W10          
S7728 2022.07.25   3 1 N24E51 0006   BXO    
S7729 2022.07.25   1 1 N20E78 0060   HAX    
S7730 2022.07.25   2   N28E42 0002   BXO    
Total spot count: 30 69 32  
Sunspot number: 100 189 132  (total spot count + 10 * number of spotted regions)
Weighted SN: 52 93 56  (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): 110 104 106  

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
2022.07 132.8 (1)   83.7 (2A) / 103.8 (2B) / 110.0 (2C) (95.3 projected, +7.2) (10.2)
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.