Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 6, 2023 at 07:00 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, 2023)
Solar cycle Solar cycles 23-25 (July 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (July 1, 2023) 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, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (July 1, 2023) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (May 29, 2023) 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 5. Solar wind speed at SOHO ranged between 337 and 426 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. A weak solar wind transient was observed beginning at DSCOVR at 13:21 UT.

Solar flux density measured at 20h UT on 2.8 GHz was 154.6 - decreasing 13.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 146.41. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.5). Three hour interval K indices: 11001223 (planetary), 21023323 (Boulder), 32001323 (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: 320) and in 11 active regions using 1K resolution (SN: 187) SDO/HMI images.

Region 13355 [S15W40] developed slowly and quietly.
Region 13357 [S07W20] decayed slowly and quietly.
Region 13358 [S13E05] decayed slowly and quietly.
Region 13359 [S21E01] still has a couple of magnetic delta configurations and could produce an M class flare.
Region 13360 [N23E08] decayed slowly and was mostly quiet. C1 flares: C1.9 @ 21:40 UT
Region 13361 [N23E29] developed slowly and has M class flare potential, mostly due to polarity intermixing.
New region 13362 [S09E62] rotated into view on July 4 and was numbered by SWPC the next day.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S8717 [S10E15] was quiet and stable.
S8725 [S19E18] was quiet and stable.
S8733 [N31E30] was quiet and stable.
New region S8734 [S20E84] rotated into view with a huge spot. While the region was mostly quiet, there is a chance of a major flare.
New region S8735 [N18W22] emerged with a tiny spot.
New region S8736 [N25E73] rotated into view with a tiny spot.
New region S8737 [N16W39] emerged with tiny spots.
New region S8738 [S37E07] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.5 00:30   13354 GOES16  
C2.5/1F 01:46   13358 GOES16 simultaneous flare in AR 13354. Incorrectly attributed to AR 13359 by SWPC
C2.4 02:04   13354 GOES16  
C2.6 02:24   13354 GOES16  
C2.3 03:16   13361 GOES16  
C3.9 03:28   13354 GOES16  
C3.1 04:08   13354 GOES16  
C3.4 04:12 N16W80 13354 GOES16  
C2.3 05:01   13354 GOES16  
C2.3 06:56   13354 GOES16 simultaneous flare in AR 13359
C2.7 08:43   13354 GOES16  
C2.3 09:15   13359 GOES16  
C4.0 09:31   13354 GOES16  
C5.1 10:39   13354 GOES16  
C7.5 10:43 N15W87 13354 GOES16  
C8.2 11:00   13354 GOES16  
C2.0 11:49   13354 GOES16  
C2.5 13:50   13354 GOES16  
C6.2 15:50 S21E07 13359 GOES16  
C5.4 16:11   13354 GOES16  
C2.2 18:00   13354 GOES16  
C4.3 18:17   S8734 GOES16  
M1.0 18:58   13354 GOES16 incorrectly attributed to AR 13361 by SWPC
C3.5 19:50   13361 GOES16  
C2.0 22:04   13354 GOES16  
C2.2 22:46   13361 GOES16 incorrectly attributed to AR 13360 by SWPC
C2.3 23:29   13361 GOES16  
C2.3 23:47   13359 GOES16  

Coronal mass ejections (CMEs)

July 3, 5: No obviously Earth directed CMEs were observed.
July 4: A filament eruption in the southeast quadrant was observed beginning near 02:30 UT and was associated with a partial halo CME. This CME could reach Earth on July 7.

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 recurrent northern hemisphere coronal hole (CH1158) was Earth facing on July 4-5. A recurrent trans equatorial coronal hole (CH1159) will likely rotate across the central meridian on July 9-11.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet to unsettled geomagnetic conditions are likely on July 6. On July 7 effects from the July 4 CME could cause unsettled to major storm conditions. A high speed stream associated with CH1158 could cause unsettled to minor storm conditions on July 7-8.

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 midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlays
Comment
SWPC/
USAF
Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
13355 2023.06.26
2023.06.27
  10 6 S16W46 0035   CRI

location: S15W40

13356 2023.06.29
2023.06.30
      S07W35         location: S08W27
S8711 2023.06.29       N14W29            
S8712 2023.06.29       S12W56            
13357 2023.06.30
2023.07.01
9 19 10 S06W21 0010 BXO BXI location: S07W20

area: 0050

13358 2023.06.30
2023.07.01
10 32 14 S11W02 0010 BXO BXI

location: S13E05

area: 0050

13359 2023.06.30
2023.07.01
12 21 14 S21W00 0140 DSO DSI

beta-gamma-delta

location: S21E01

area: 0230

S8717 2023.06.30   12 2 S10E15 0030   BXO  
S8718 2023.06.30       N14W30            
13360 2023.06.30
2023.07.01
6 20 9 N23E07 0030 CRO CAO

location: N23E08

area: 0080

S8720 2023.06.30       N30W51            
S8721 2023.06.30       N17W14            
S8724 2023.07.02       N09W01            
S8725 2023.07.02   10 2 S20E18 0015   BXO  
S8726 2023.07.02       S37W01            
13361 2023.07.02
2023.07.04
3 34 17 N23E31 0010 CAO EAI beta-gamma

location: N23E29

area: 0230

suspect SWPC data

S8729 2023.07.02       N40W59            
S8730 2023.07.03       N18E02            
13362 2023.07.04
2023.07.05
1 1 1 S10E60 0120 HSX HSX location: S09E62
S8733 2023.07.04   3   N31E30 0003   AXX  
S8734 2023.07.05   2 1 S20E84 0770   HHX    
S8735 2023.07.05   1   N18W22 0003   AXX    
S8736 2023.07.05   1   N25E73 0002   AXX    
S8737 2023.07.05   3   N16W39 0003   BXO    
S8738 2023.07.05   1 1 S37E07 0004   AXX    
Total spot count: 41 170 77  
Sunspot number: 101 320 187  (total spot count + 10 * number of spotted regions)
Weighted SN: 59 203 110  (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): 111 176 150  

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 (SC24 solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(SC24 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
2021.12 103.0 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 64.7 (+4.6) 10.46
2022.03 117.0 115.8 78.6 68.7 (+4.0) 10.20
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.4 (+4.4) 7.48
2022.06 116.1 119.8 70.3 81.1 (+3.7) 8.20
2022.07 125.4 129.5 91.4 86.7 (+5.6) 9.51
2022.08 114.2 117.1 74.6 92.5 (+5.8) 10.92
2022.09 135.1 136.5 96.0 96.4 (+3.9) 12.18
2022.10 133.5 132.7 95.5 98.7 (+2.3) 11.16
2022.11 123.4 120.7 80.5 101.0 (+2.3) 9.33
2022.12 147.9 143.4 112.8 106.6 (+5.6) 10.99
2023.01 182.4 176.6 143.6 (113.7 projected, +6.1) 8.73
2023.02 167.2 163.2 110.9 (118.5 projected, +4.8) 14.48
(current
SC25 peak)
2023.03 157.2 155.6 122.6 (121.6 projected, +3.1) 14.42
2023.04 145.4 146.4 96.4 (127.0 projected, +5.4) 13.40
2023.05 155.6 159.2 137.9 (132.7 projected, +5.7) 10.67
2023.06 161.7 166.8 163.4 (135.9 projected, +3.2) 8.9
2023.07  166.1 (1)   18.8 (2A) / 116.8 (2B) / 172.4 (2C) (135.4 projected, -0.5) (4.3)
2023.08       (136.4 projected, +1.0)  
2023.09       (139.8 projected, +3.4)  
2023.10       (141.6 projected, +1.8)  
2023.11       (144.2 projected max SC25, +2.6)  
2023.12       (143.4 projected, -0.1)  
2024.01       (140.1 projected, -3.3)  

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: WDC-SILSO, Royal Observatory Of Belgium, Brussels

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.