Solar Terrestrial Activity Report

Activity chart

Last major update issued on August 3, 2022 at 06:20 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 (August 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (August 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 (August 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (August 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 August 2, weakly under the influence of a high speed coronal hole stream from CH1091. Solar wind speed at SOHO ranged between 462 and 569 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 97.8 - decreasing 16.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 106.88). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.5). Three hour interval K indices: 22221222 (planetary), 22322323 (Boulder), 33232344 (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 5 active regions using 2K resolution (SN: 95) and in 4 active regions using 1K resolution (SN: 60) SDO/HMI images.

Region 13067 [N19W28] was quiet and stable.
Region 13068 [S16W13] gained spots and has polarity intermixing. A C1.3 flare was recorded at 02:47 UT on August 3.
Region 13070 [N15E33] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S7741 [S18E71] was quiet and stable.
S7742 [N17W08] was quiet and stable.

AR 13066 behind the southwest limb was the most active region. A C1.7 flare was recorded at 17:20 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.2 15:33 behind southwest limb 13066 GOES16  

Coronal mass ejections (CMEs)

July 31 - August 2: 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 (CH1091) rotated across the central meridian on July 30 - August 1. A recurrent trans equatorial hemisphere coronal hole (CH1092) will likely become Earth facing on August 5-6.

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 unsettled conditions are expected for August 3-4 due to a high speed stream from CH1091 becoming quiet on August 5-7. Quiet to minor storm conditions are possible on August 8-9 due to effects from CH1092.

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
S7728 2022.07.25       N24W53            
13067 2022.07.25
2022.07.26
  2 1 N21W28 0004   AXX location: N19W28
S7731 2022.07.27       S10W47            
13068 2022.07.27
2022.07.28
15 38 17 S15W12 0180 ESI ESI beta-gamma

location: S16W13

13069 2022.07.29
2022.07.31
      S18W64            
S7738 2022.07.30       S22W22            
S7739 2022.07.31       S14W39            
13070 2022.07.31
2022.08.01
  1   N15E36 0001   AXX location: N15E33
S7741 2022.08.01   1 1 S18E71 0120   HSX  
S7742 2022.08.01   3 1 N17W08 0006   AXX  
S7743 2022.08.01       S19E26          
Total spot count: 15 45 20  
Sunspot number: 25 95 60  (total spot count + 10 * number of spotted regions)
Weighted SN: 20 55 30  (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): 28 52 48  

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
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 31.4 (+3.8) 5.51
2021.08 77.7 79.7 22.0 35.4 (+4.0) 6.19
2021.09 87.0 88.2 51.3 40.2 (+4.8) 6.33
2021.10 88.9 88.3 37.4 45.2 (+5.0) 7.38
2021.11 86.2 84.4 34.8 50.8 (+5.6) 9.83
2021.12 103.0 99.8 67.5 55.9 (+5.1) 6.40
2022.01 103.8 100.5 55.3 60.1 (+4.2) 8.92
2022.02 109.1 106.5 60.9 (65.8 projected, +5.7) 10.46
2022.03 117.0 115.8 78.6 (70.8 projected, +5.0) 10.20
2022.04 130.8 131.7 84.1 (75.9 projected, +5.1) 11.79
2022.05 133.8 136.8 96.5 (82.4 projected, +6.5) 7.48
2022.06 116.1 119.8 70.5 (88.3 projected, +5.9) 8.20
2022.07 125.4 129.5 91.4 (95.5 projected, +7.2) 9.6
2022.08 96.6 (1)   1.8 (2A) / 28.5 (2B) / 103.7 (2C) (102.0 projected, +6.5) (7.3)
2022.09       (106.9 projected, +4.9)  
2022.10       (110.1 projected, +3.2)  
2022.11       (112.9 projected, +2.8)  
2022.12       (117.7 projected, +4.8)  
2023.01       (123.7 projected, +6.0)  
2023.11       (142.5 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.