Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 28, 2022 at 20:45 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 27 under the influence of a high speed stream from CH1070. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 130 - increasing 31.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 89.28). The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.3). Three hour interval K indices: 22233443 (planetary), 22234443 (Boulder), 33132545 (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 12 active regions using 2K resolution (SN: 290) and in 10 active regions using 1K resolution (SN: 171) SDO/HMI images.

Region 12974 [S19E00] was quiet and stable.
Region 12975 [N13E04] merged with AR S7451 and more flux emerged creating strong polarity intermixing and magnetic deltas. The region could produce a major flare. On March 28 the region produced an M4.0 proton flare at 11:28 and an M1.0 flare at 17:40 UT. The M4 flare was associated with an EIT wave and a fast full halo CME. C1 flares: C1.0 at 18:30, C1.1 at 22:40, C1.1 @ 23:20 UT.
Region 12976 [N15E20] was quiet and stable. The region has a magnetic delta at the northern edge of the main penumbra. An M class flare is possible.
New region 12977 [N22W10] emerged on March 26 and was numbered the next day by SWPC.
New region 12978 [S17E78] rotated into view and has M class flare potential. C1 flares: C1.2 @ 15:18, C1.2 @ 16:18 UT

Spotted regions not observed (or interpreted differently) by SWPC:
S7449 [S20E24] developed as new flux emerged in the southern part of the region.
New region S7453 [S27W09] emerged with a tiny spot.
New region S7455 [S24W45] emerged with tiny spots.
New region S7456 [N08W12] emerged with tiny spots.
New region S7457 [N25E42] emerged with a tiny spot.
New region S7458 [S24E80] rotated into view just south of AR 12978. C1 flares: C1.0 @ 08:36, C1.1 @ 10:15 UT
New region S7459 [N40E36] emerged with a faint spot at a high latitude.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.4 11:09   12978 GOES16  
C4.1 00:10 (on March 28, flare began at 23:56)   12978 GOES16  

Coronal mass ejections (CMEs)

March 26-27: No obviously Earth directed CMEs were observed in available LASCO imagery.
March 28: A full halo CME was observed after the M4 event in AR 12975. The CME could reach Earth on March 30 and cause unsettled to severe storm conditions.

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. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet to active conditions are likely on March 28 as a high speed stream from CH1070 is the dominant solar wind source. Quiet to unsettled conditions are likely on March 29. Quiet to major storm conditions are possible on March 30-31 if the March 28 CME impacts Earth, isolated severe storm intervals are not unlikely.

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
12972 2022.03.19
2022.03.19
      S29W88           location: S27W84
12973 2022.03.19
2022.03.20
      N19W48            
S7438 2022.03.19       N17W21          
12974 2022.03.21
2022.03.22
1 18 5 S19W02 0010 AXX CRO

location: S19E00

area: 0030

S7442 2022.03.21       N19W51            
S7443 2022.03.21       S24W07            
12975 2022.03.22
2022.03.23
22 55 27 N12E05 0050 CSI DAC

beta-gamma-delta

location: N13E04

area: 0300

12976 2022.03.22
2022.03.24
15 44 20 N16E22 0500 EHO EKC beta-delta

location: N15E20

S7448 2022.03.25       N18W08          
S7449 2022.03.25   11 3 S20E24 0020   BXO  
S7450 2022.03.25       S18W49            
S7451 2022.03.26                 merged with AR 12975
12977 2022.03.26
2022.03.27
8 16 8 N21W11 0040 DRO DRI  
S7453 2022.03.27   1 1 S27W09 0003   AXX    
12978 2022.03.27
2022.03.27
1 8 3 S15E75 0180 HSX EHO   was AR S7454

area: 0580

S7455 2022.03.27   4 1 S24W45 0010   CRO    
S7456 2022.03.27   4 2 N08W12 0010   CRO    
S7457 2022.03.27   4   N25E42 0005   BXO    
S7458 2022.03.27   4 1 S24E80 0010   BXO    
S7459 2022.03.27   1   N40E36 0001   AXX    
Total spot count: 47 170 71  
Sunspot number: 97 290 171  (total spot count + 10 * number of spotted regions)
Weighted SN: 70 207 108  (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): 107 160 137  

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
2022.03 112.0 (1)   56.0 (2A) / 64.3 (2B) / 82.6 (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.