Solar Terrestrial Activity Report

Activity chart

Last major update issued on May 15, 2022 at 08:40 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 14. The high latitude magnetometer at Andenes recorded quiet to active levels. A high speed stream, likely associated with CH1078, arrived during the latter half of May 14 and a geomagnetic disturbance began early on May 15.

Solar flux density measured at 20h UT on 2.8 GHz was 152.7 - increasing 17.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 96.64). 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: 21111322 (planetary), 21222322 (Boulder), 32122244 (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 10 active regions using 2K resolution (SN: 275) and in 9 active regions using 1K resolution (SN: 174) SDO/HMI images.

Region 13006 [S29W62] decayed further and could become spotless before rotating out of view. C1 flares: C1.8 @ 12:19 UT
Region 13007 [S22W08] lost area in the trailing spot section while area increased in the leading spot section. The region gained spots and remained mostly quiet. Despite the high number of spots there is only weak polarity intermixing near the center of the region. C1 flares: C1.6 @ 05:15 UT
Region 13008 [N16W06] decayed slowly and quietly.
Region 13010 [S14E49] decayed as all but one of the larger spots lost mature penumbra and fragmented into smaller spots.
Region 13011 [N17E50] was quiet and stable. There seems to be some confusion internally at SWPC about this region as the one responsible for flare analysis assigns flares in AR S7569 to AR 13011.
New region 13013 [S28E29] was first observed with spots on May 11 with SWPC numbering the region 3 days later as slow development occurred.

Spotted regions not observed (or interpreted differently) by SWPC:
S7568 [N13E13] was quiet and stable.
S7569 [N13E67] produced several C flares and appeared to be decaying slowly. C1 flares: C1.5 @ 03:59, C1.8 @ 14:27 UT
S7570 [N22E68] was mostly quiet and stable.
New region S7571 [N01W28] emerged with tiny spots. This is an SC24 group.

A region behind the northeast limb produced a C1.6 at 04:27 and a C1.9 flare at 07:38 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.0 09:25 behind NE limb   GOES16  
C2.0 10:58   13007 GOES16  
C2.1 15:16 N13E72 S7569 GOES16 SWPC (San Vito) reports incorrect location N14E82
C2.3 16:25 behind NE limb   GOES16  
C3.6 19:30   13006 GOES16  
C4.2 20:16 S12E55 13010 GOES16  
C3.1 21:37 behind NE limb   GOES16  
C5.7 22:07 S13E51 13010 GOES16  
C4.5 22:38 S13E52 13010 GOES16  
M2.2 00:08 (on May 15) behind NE limb (N13E90)   GOES16  

Coronal mass ejections (CMEs)

May 12-14: 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 likely 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

Unsettled to minor storm conditions are possible on May 15-16 due to effects from CH1078 becoming quiet to unsettled on May 17.

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
8 12 6 S31W59 0010 BXO BXI

location: S29W62

area: 0025

13007 2022.05.07
2022.05.08
30 75 42 S24W08 0340 EKC EKI

area: 0550

location: S22W08

S7555 2022.05.08       N02W46           likely SC24 group
13012 2022.05.09
2022.05.13
      S19W12         location: S17W17
13008 2022.05.10
2022.05.11
  6 1 N16W06 0010   BXO  
13013 2022.05.11
2022.05.14
3 12 4 S28E29 0010 BXO CRI area: 0025
13009 2022.05.11
2022.05.11
      N14W61        

location: N16W63

S7561 2022.05.11       N21W32            
13010 2022.05.11
2022.05.12
12 38 18 S15E48 0190 DSO EAI

location: S14E49

S7564 2022.05.12       S13W27            
13011 2022.05.12
2022.05.13
2 7 3 N16E53 0030 CRO DRO

location: N17E50

S7566 2022.05.12       N35W34            
S7567 2022.05.12       N19W14            
S7568 2022.05.13   5   N15E15 0010   BXO  
S7569 2022.05.13   12 6 N13E67 0250   CSO  
S7570 2022.05.13   6 3 N22E68 0040   CAO  
S7571 2022.05.14   2 1 N01W28 0005   BXO   SC24 group
Total spot count: 55 175 84  
Sunspot number: 105 275 174  (total spot count + 10 * number of spotted regions)
Weighted SN: 73 206 115  (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): 116 151 139  

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
2022.05 124.0 (1)   34.8 (2A) / 77.1 (2B) / 98.2 (2C) (82.3 projected, +6.4) (5.0)
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.