Solar Terrestrial Activity Report

Activity chart

Last major update issued on May 17, 2022 at 09:40 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 16 under the influence of a high speed stream associated with CH1078. The high latitude magnetometer at Andenes recorded quiet to active levels. A high speed stream associated with CH1079 was observed beginning at 01:38 UT on May 17 at DSCOVR.

Solar flux density measured at 20h UT on 2.8 GHz was 161.7 - increasing 1.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 97.11). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 8.9). Three hour interval K indices: 13332221 (planetary), 24332322 (Boulder), 23333342 (Andenes).

The background x-ray flux is at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 328) and in 9 active regions using 1K resolution (SN: 175) SDO/HMI images.

Region 13006 [S34W80] rotated partly out of view while slowly decaying.
Region 13007 [S22W34] decayed slowly and quietly.
Region 13008 [N16W35] was quiet and stable.
Region 13010 [S17E22] decayed slowly losing spots and area.
Region 13011 [N17E24] decayed slowly and quietly.
Region 13013 [S27E03] decayed slowly and quietly.
Region 13014 [N21E42] developed quickly during the latter half of the day and gained a magnetic delta in the main penumbra. M class flaring is likely if the current development continues. C1 flares: C1.9 @ 07:50 UT
Region 13015 [N13E39] was mostly quiet and stable. C1 flares: C1.7 @ 09:40, C1.8 @ 19:41 UT
New region 13016 [S18E73] rotated into view on May 15 with SWPC numbering the region the following day. C1 flares: C1.5 @ 00:50, C1.6 @ 04:02, C1.8 @ 04:42 UT
New region 13017 [N13E66]  rotated into view on May 15 and received its NOAA number the next day. The group is unimpressive, yet managed to produce an M class flare.

Spotted regions not observed (or interpreted differently) by SWPC:
S7568 [N13W12] decayed slowly and quietly.
New region S7575 [S11E68] emerged with tiny spots.
New region S7576 [N31W01] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.6 10:14   13017 GOES16  
M2.4 13:27 N14E73 13017 GOES16  
C5.5 14:27   13017 GOES16  
C2.4 17:13   13010 GOES16  
C2.6 18:21   13014 GOES16  
C2.5 20:47 N22E44 13014 GOES16  
C2.7 21:32   13014 GOES16  
C2.4 23:14 N14E36 13015 GOES16  
C2.3 23:30   13014 GOES16  

Coronal mass ejections (CMEs)

May 14-16: 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 northern hemisphere coronal hole (CH1078) rotated across the central meridian on May 12-14. A trans equatorial coronal hole (CH1079) will be Earth facing on May 15-17.

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 May 17-19 due to effects from CH1079.

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
13006 2022.05.02
2022.05.04
  2   S31W86 0002   AXX location: S34W80
13007 2022.05.07
2022.05.08
36 51 25 S23W35 0320 EKC EAI

location: S22W34

area: 0200

13012 2022.05.09
2022.05.13
      S19W39           location: S17W43
13008 2022.05.10
2022.05.11
  2   N16W33 0002   BXO  
13013 2022.05.11
2022.05.14
2 2 1 S27E03 0000 AXX AXX area: 0005
13009 2022.05.11
2022.05.11
      N14W88          

 

S7561 2022.05.11       N21W58            
13010 2022.05.11
2022.05.12
23 43 21 S16E24 0100 CSO ERI

location: S17E22

S7564 2022.05.12       S13W53            
13011 2022.05.12
2022.05.13
3 10 5 N16E25 0010 BXO BXO

location: N17E24

S7567 2022.05.12       N19W40            
S7568 2022.05.13   3   N13W12 0004   BXO  
13015 2022.05.13
2022.05.15
7 26 8 N13E39 0110 HSX CAI  
13014 2022.05.13
2022.05.15
13 37 13 N22E44 0140 DAC DAC beta-delta

area: 0260

location: N21E42

S7571 2022.05.14       N01W54           SC24 group
13016 2022.05.15
2022.05.16
3 5 3 S18E73 0100 HSX DSO  
S7573 2022.05.15       N05E11         likely SC24 group
13017 2022.05.15
2022.05.16
6 12 7 N13E66 0020 CRO CRI area: 0040
S7575 2022.05.16   4 2 S11E68 0010   BXO    
S7576 2022.05.16   1   N31W01 0001   AXX    
Total spot count: 93 198 85  
Sunspot number: 173 328 175  (total spot count + 10 * number of spotted regions)
Weighted SN: 126 224 121  (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): 190 180 140  

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) 11.79
2022.05 128.2 (1)   44.6 (2A) / 86.4 (2B) / 103.1 (2C) (82.3 projected, +6.4) (5.7)
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.