Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 31, 2022 at 08:55 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 active on March 30. The high latitude magnetometer at Andenes recorded quiet to active levels. A solar wind shock was observed at 01:41 UT on March 31 at DSCOVR, the arrival of one or both CMEs observed on March 28. The geomagnetic field has since been at minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 151 - increasing 39.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 89.91). 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: 01110224 (planetary), 01032323 (Boulder), 10110246 (Andenes).

The background x-ray flux was at the class C1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 16 active regions using 2K resolution (SN: 344) and in 11 active regions using 1K resolution (SN: 197) SDO/HMI images.

Region 12974 [S20W38] decayed slowly and quietly.
Region 12975 [N13W37] saw consolidation in the central and eastern parts and less polarity intermixing. The region could produce another major flare as it still has a magnetic delta. C1 flares: C1.2 @ 01:40, C1.3 @ 08:10, C1.1 @ 10:17 UT.
Region 12976 [N15W20] was mostly quiet and stable. Numerous tiny spots emerged in the trailing spot section and there is some polarity intermixing in that area. An M class flare is possible. C1 flares: C1.8 @ 01:12, C1.2 @ 08:42 UT.
Region 12978 [S17E38] was mostly quiet and stable and has M class flare potential.
Region 12979 [S19W14] decayed slowly and quietly.
Region 12980 [N08W53] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S7455 [S24W82] developed late in the day as new flux emerged.
S7458 [S25E46] developed late in the day with many new spots forming. There is polarity intermixing and an M class flare is possible.
S7462 [S14E09] decayed slowly and quietly.
S7465 [S04W50] was quiet and stable. This is an SC24 group.
S7466 [N21W45] was quiet and stable.
S7467 [S19W01] was quiet and stable.
S7468 [S19E74] was quiet and stable.
New region S7469 [S17E59] emerged with tiny spots.
New region S7470 [N23E82] rotated into view.
New region S7471 [N12E28] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.0 02:24 N12W12 12975 GOES16  
C2.2 04:31   12975 GOES16  
C2.0 05:01   12975 GOES16  
C2.6 05:46   12975 GOES16  
C2.3 06:46   12975 GOES16 attributed to AR 12978 by SWPC
C2.1 10:48   12975 GOES16  
C6.7 11:04   12975 GOES16  
C2.2 11:22   12975 GOES16  
C4.5 12:35   12975 GOES16  
C3.6 12:54   12976 GOES16  
C2.6 13:59   12975 GOES16  
C2.0 14:46   S7458 GOES16  
C2.2 15:52   12975 GOES16  
X1.3 17:37   12975 GOES16 halo CME, strong type II radio sweep
C2.6 21:28   12975 GOES16  
C2.7 21:52   S7458 GOES16  

Coronal mass ejections (CMEs)

March 30: A full halo CME was observed after the X1 event in AR 12975. The CME could impact Earth on April 1 or early on April 2 and cause active to major storm conditions. Another and more impressive full halo CME was observed early in the day in LASCO imagery. The source of this event was likely backsided, about 6 days behind the northeast limb given the distribution of the ejecta.
March 29
: No obviously Earth directed CMEs were observed in available LASCO imagery.
March 28: A full halo CME was observed at noon after the M4 event in AR 12975. The CME could reach Earth on March 30 or early on March 31 and cause unsettled to major storm conditions. Another full halo CME was observed after a C8.6 flare in AR 12975 peaking at 20:04 UT. This CME could reach Earth early on March 31.

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 southern hemisphere coronal hole (CH1071) will likely rotate across the central meridian on March 30-31.

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.

Forecast

Unsettled to major storm is likely on March 31 becoming quiet to active on April 1. Quiet to major storm conditions are possible from late on April 1 until April 3 due to the March 30 CME.

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
12974 2022.03.21
2022.03.22
  3   S19W41 0003   AXX

location: S20W38

S7443 2022.03.21       S24W46            
12975 2022.03.22
2022.03.23
20 53 33 N13W38 0330 DKC EKC

beta-gamma-delta

area: 0400

12976 2022.03.22
2022.03.24
4 42 17 N15W18 0550 EKO EKO

beta-gamma

location: N15W20

S7448 2022.03.25       N18W47            
12979 2022.03.25
2022.03.28
  8 2 S22W20 0012   BXO location: S19W14
12977 2022.03.26
2022.03.27
      N18W50         location: N21W51
S7453 2022.03.27       S27W48            
12978 2022.03.27
2022.03.27
8 22 9 S19E39 0670 DHO EHO

location: S17E39

S7455 2022.03.27   3 1 S24W82 0005   BXO  
12980 2022.03.27
2022.03.28
1 2   N04W53 0010 BXO BXO area: 0003

location: N08W53

S7457 2022.03.27       N25E03            
S7458 2022.03.27   32 17 S25E46 0100   DRI beta-gamma
S7459 2022.03.27       N40W05            
S7460 2022.03.28       S33W53            
S7461 2022.03.28       N20E12            
S7462 2022.03.28   4   S14E09 0005   BXO  
S7463 2022.03.28       S42E23            
S7464 2022.03.28       S28E20            
S7465 2022.03.29   6 3 S04W50 0020   CRO SC24 group
S7466 2022.03.29       N21W43          
S7467 2022.03.29   2 1 S19W01 0004   BXO  
S7468 2022.03.29   2 1 S18E74 0040   HAX  
S7469 2022.03.30   4 2 S17E59 0013   BXO    
S7470 2022.03.30   1 1 N23E82 0050   HAX    
S7471 2022.03.30   2   N12E28 0003   BXO    
Total spot count: 33 186 87  
Sunspot number: 73 346 197  (total spot count + 10 * number of spotted regions)
Weighted SN: 63 232 133  (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): 80 190 158  

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
2022.03 116.0 (1)   66.4 (2A) / 68.6 (2B) / 91.4 (2C) (67.9 projected, +5.5) (9.6)
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.