Solar Terrestrial Activity Report

Activity chart

Last major update issued on May 10, 2022 at 10:10 UT. Minor update posted at 19:10 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 (May 1, 2022)
Solar cycle Solar cycles 23-25 (May 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (May 1, 2022) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (June 1, 2020) POES auroral activity level October 2009 - December 2012]
  Comparison of cycles 21-25 (May 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (May 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 May 9. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.

Solar flux density measured at 20h UT on 2.8 GHz was 117.0 - increasing 21.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 95.79). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 23211110 (planetary), 34222311 (Boulder), 33222222 (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 7 active regions using 2K resolution (SN: 166) and in 5 active regions using 1K resolution (SN: 92) SDO/HMI images.

Region 13004 [S13W83] was mostly quiet and stable. C1 flares: C1.2 @ 20:57 UT (this flare was incorrectly attributed to AR 13007 by SWPC).
Region 13006 [S30E04] developed slowly with many small spots appearing. The magnetic delta, which has been present since the region rotated into view, strengthened. The region could produce a major flare. C1 flares: C1.5 @ 18:03, C1.0 @ 19:54, C1.2 @ 21:26 UT
Region 13007 [S23E58] was somewhat active and could produce a minor M class flare. C1 flares: C1.0 @ 17:41 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S7542 [S16W73] reemerged with a tiny spot.
S7551
[N27W13] reemerged with tiny spots.
New region S755
6 [N23E09] was observed with tiny spots in an old plage area.
New region S7557 [S18E49] emerged with tiny spots.

Minor update added at 19:10 UT on May 10: AR 13007 was the source of a C4.7 long duration event at 13:36 UT. Development occurred in the central spot section with opposite polarity spots not well separated. Then AR 13006 generated a major impulsive X1.5 flare at 13:55 UT, this event was associated with a fast EIT wave, however, no Earth directed CME were observed in initial LASCO imagery. The center of this flare was in the spot containing the magnetic delta. The X1 flare appeared to trigger a long duration M1.0 further southeast in the region, this event peaked at 14:33 UT.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.5 01:05   13004 GOES16  
C2.1 14:31 S22E67 13007 GOES16  

Coronal mass ejections (CMEs)

May 7-9: 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 (CH1077) rotated across the central meridian on May 7.

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 occasionally unsettled conditions are likely on May 9. On May 10-11 there is a chance of unsettled intervals due to weak effects from CH1077.

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
13001 2022.04.25
2022.04.26
1     S32W92 0060 HSX    

rotated out of view

13004 2022.04.27
2022.05.02
1 5 2 S13W85 0180 HSX CKO

area: 0320

13003 2022.04.28
2022.04.29
      S24W81          

 

13005 2022.05.01
2022.05.02
1     N20W90 0000 AXX       this is AR S7553. NOAA location is incorrect

rotated out of view

S7538 2022.05.02       S19W50            
13006 2022.05.02
2022.05.04
10 55 26 S31E04 0050 CSO DAC beta-gamma-delta

location: S30E04

area: 0130

S7540 2022.05.02       S13W09            
S7542 2022.05.04   1   S16W73 0001   AXX    
S7546 2022.05.05       S25W34            
S7548 2022.05.05       S18W19            
S7549 2022.05.05       N25W51            
S7550 2022.05.06       S18W55            
S7551 2022.05.06   6   N28W27 0010   BXO    
13007 2022.05.07
2022.05.08
8 23 12 S24E58 0160 DSO FSI

area: 0180

S7554 2022.05.07       S29W24            
S7555 2022.05.08       N02E19         likely SC24 group
S7556 2022.05.09   3 1 N23E09 0005   AXX    
S7557 2022.05.09   3 1 S18E49 0005   BXO    
Total spot count: 21 96 42  
Sunspot number: 71 166 92  (total spot count + 10 * number of spotted regions)
Weighted SN: 41 116 62  (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): 78 91 74  

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
 

2020.10

74.6 74.2 14.6 11.9 (+1.4) 6.13
2020.11 89.9 88.0 34.5 13.6 (+1.7) 4.77
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 (50.0 projected, +5.0) 9.83
2021.12 103.0 99.8 67.5 (55.8 projected, +5.8) 6.40
2022.01 103.8 100.5 54.0 (60.3 projected, +4.5) 8.92
2022.02 109.1 106.5 59.7 (65.2 projected, +4.9) 10.46
2022.03 117.0 115.8 78.5 (70.7 projected, +5.5) 10.20
2022.04 130.8 131.7 84.1 (75.9 projected, +5.2) 12.0
2022.05 117.7 (1)   19.3 (2A) / 66.3 (2B) / 89.3 (2C) (82.3 projected, +6.4) (4.8)
2022.06       (88.2 projected, +5.9)  
2022.07       (95.4 projected, +7.2)  
2022.08       (102.1 projected, +6.7)  
2022.09       (107.1 projected, +5.0)  
2022.10       (110.3 projected, +3.2)  

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.