Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 26, 2022 at 11:20 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 25 under the lingering influence of a high speed stream from CH1069. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 112 - increasing 15.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 89.02). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.4). Three hour interval K indices: 33122111 (planetary), 33332321 (Boulder), 44133332 (Andenes).

The background x-ray flux is at the class B4 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 7 active regions using 2K resolution (SN: 136) and in 4 active regions using 1K resolution (SN: 65) SDO/HMI images.

Region 12974 [S18E27] displayed no significant change, yet managed to produce an M1.4 flare.
Region 12975 [N12E31] decayed slowly and quietly. The easternmost spots are now quite close to the leading spots of AR 12976 and some interaction is possible.
Region 12976 [N15E47] was mostly quiet and could produce M class flares.

Spotted regions not observed (or interpreted differently) by SWPC:
S7438 [N14E02] was quiet and stable.
New region S7448 [N17E19] emerged with tiny spots.
New region S7449 [S15E52] was observed with tiny spots in an old plage area.
New region S7450 [S18W23] emerged near CH1070 with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 02:45   12976 GOES16  
M1.4/1F 05:26 S21E36 12974 GOES16 LDE, CME, weak type II and IV radio sweeps

Coronal mass ejections (CMEs)

March 23-24: 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.

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 26-28 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.

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
      N16W67           location: N18W60
12972 2022.03.19
2022.03.19
      S29W60         location: S27W58
12973 2022.03.19
2022.03.20
      N19W20            
S7438 2022.03.19   4   N14E02 0004   AXX  
12974 2022.03.21
2022.03.22
2 13 6 S19E25 0030 CRO CRO

area: 0050

S7442 2022.03.21       N19W25            
S7443 2022.03.21       S24E19            
S7444 2022.03.21       S29W54            
12975 2022.03.22
2022.03.23
5 13 5 N12E39 0160 ESO EAO

location: N12E31

area: 0080

SWPC location is way off

12976 2022.03.22
2022.03.24
13 27 11 N16E47 0450 EHO EHO location: N15E47
S7448 2022.03.25   5 3 N17E19 0015   BXO    
S7449 2022.03.25   2   S15E52 0002   AXX    
S7450 2022.03.25   2   S18W23 0002   BXO    
Total spot count: 20 66 25  
Sunspot number: 50 136 65  (total spot count + 10 * number of spotted regions)
Weighted SN: 38 84 43  (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): 55 75 52  

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
2022.03 110.9 (1)   51.3 (2A) / 63.6 (2B) / 77.5 (2C) (67.9 projected, +5.5) (9.9)
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.