Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 27, 2022 at 09:00 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 (March 1, 2022)
Solar cycle Solar cycles 23-25 (March 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (March 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 (March 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (March 1, 2022) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (August 22, 2021) 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 March 26. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. Effects from CH1070 became noticeable after 15h UT. The interplanetary magnetic field has been mostly northwards afterwards causing only a minor disturbance so far.

Solar flux density measured at 20h UT on 2.8 GHz was 119 - increasing 22.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 89.14). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.0). Three hour interval K indices: 21110232 (planetary), 10131322 (Boulder), 40011352 (Andenes).

The background x-ray flux is at the class B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 173) and in 6 active regions using 1K resolution (SN: 100) SDO/HMI images.

Region 12974 [S19E13] decayed slowly and quietly.
Region 12975 [N12E17] decayed slowly and was mostly quiet.
Region 12976 [N15E33] was quiet and stable. The region has weak polarity intermixing and could produce M class flares.

Spotted regions not observed (or interpreted differently) by SWPC:
S7438 [N17W08] was quiet and stable.
S7448 [N18E06] was quiet and stable.
S7449 [S13E40] was quiet and stable
New region S7451 [N14E12] emerged near AR 12975 with several spots.
New region S7452 [N21E02] emerged with tiny spots.

An active region is rotating into view at the southeast limb early on March 27. The region produced a C2 flare and may have M class flare potential.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.3 15:38 behind SE limb   GOES16  

Coronal mass ejections (CMEs)

March 24, 26: No obviously Earth directed CMEs were observed in available LASCO imagery.
March 25: A CME was observed after the M1.4 event in AR 12974. The CME could reach Earth sometime between noon on March 27 and the early hours of March 28.

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 trans equatorial coronal hole (CH1070) was in an Earth facing position on March 23-25. A southern hemisphere coronal hole (CH1071) will likely rotate across the central meridian on March 30.

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

Quiet to minor storm conditions are likely on March 27-28 as a high speed stream from CH1070 becomes the dominant solar wind source. The March 25 CME could further increase the disturbance level on March 27 and 28, maybe reaching major storm levels. Quiet to unsettled conditions are likely on March 29.

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
12971 2022.03.15
2022.03.17
      N16W81           location: N18W73
12972 2022.03.19
2022.03.19
      S29W74           location: S27W71
12973 2022.03.19
2022.03.20
      N19W34            
S7438 2022.03.19   4   N17W08 0004   AXX  
12974 2022.03.21
2022.03.22
2 15 4 S19E11 0020 HRX CRO

location: S19E13

S7442 2022.03.21       N19W38            
S7443 2022.03.21       S24E06            
12975 2022.03.22
2022.03.23
3 18 5 N12E20 0040 HSX CAO

location: N12E17

area: 0070

12976 2022.03.22
2022.03.24
13 35 21 N20E27 0530 EHO EKO beta-gamma

location: N15E33

S7448 2022.03.25   4 3 N18E06 0012   BXO  
S7449 2022.03.25   3   S13E40 0003   AXX  
S7450 2022.03.25       S18W36          
S7451 2022.03.26   10 5 N14E12 0040   CRI    
S7452 2022.03.26   4 2 N21E02 0010   BXO    
Total spot count: 18 93 40  
Sunspot number: 48 173 100  (total spot count + 10 * number of spotted regions)
Weighted SN: 36 114 61  (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): 53 95 80  

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
2020.08 71.6 73.4 7.5 9.5 (+0.5) 5.68
2020.09 70.7 71.4 0.7 10.5 (+1.0) 8.59
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 27.7 (+1.9) 5.52
2021.07 81.0 83.6 34.3 31.4 (+3.7) 5.51
2021.08 77.7 79.7 22.0 35.3 (+3.9) 6.19
2021.09 87.0 88.2 51.3 (39.9 projected, +4.6) 6.33
2021.10 88.9 88.3 38.1 (43.6 projected, +3.7) 7.38
2021.11 86.2 84.4 35.0 (48.2 projected, +4.6) 9.83
2021.12 103.0 99.8 67.6 (54.0 projected, +5.8) 6.40
2022.01 103.8 100.5 54.0 (57.7 projected, +3.7) 8.92
2022.02 109.1 106.5 59.7 (62.4 projected, +4.7) 10.46
2022.03 111.3 (1)   52.9 (2A) / 63.0 (2B) / 79.3 (2C) (67.9 projected, +5.5) (9.7)
2022.04       (73.0 projected, +5.1)  
2022.05       (79.4 projected, +6.4)  
2022.06       (85.3 projected, +5.9)  
2022.07       (92.6 projected, +7.3)  
2022.08       (99.2 projected, +6.6)  

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.