Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 30, 2022 at 08:05 UT. Minor update posted at 17:50 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 on March 29. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 149 - increasing 39.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 89.70). 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: 12211222 (planetary), 12323422 (Boulder), 10122344 (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 14 active regions using 2K resolution (SN: 298) and in 11 active regions using 1K resolution (SN: 190) SDO/HMI images.

Region 12974 [S19W25] was quiet and stable.
Region 12975 [N13W24] is a complex region with multiple magnetic deltas. The region could produce a major flare. C1 flares: C1.8 @ 14:09, C1.4 @ 16:50, C1.5 @ 17:26, C1.8 @ 22:19 UT.
Region 12976 [N15W07] lost the magnetic delta and decayed slightly. An M class flare is possible.
Region 12977 [N21W38] decayed slowly and quietly.
Region 12978 [S17E52] was mostly quiet and stable and has M class flare potential.
Region 12979 [S19W03] decayed slowly and quietly.
Region 12980 [N08W40] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC:
S7455 [S23W73] was quiet and stable.
S7458 [S24E58] gained a few spots and was somewhat unstable and produced several C flares. C1 flares: C1.3 @ 18:26 UT.
S7462 [S16E24] was quiet and stable.
New region S7465 [S04W38] emerged near the equator and is an SC24 group.
New region S7466 [N21W30] emerged with a tiny spot.
New region S7467 [S19E11] emerged with tiny spots.
New region S7468 [S19E87] rotated partly into view at the southeast limb.

Minor updated added at 17:50 UT: AR 12975 was the source of an impulsive X1.3 flare at 17:37 UT. It is too early too tell if the event will increase proton levels at Earth and if there was a CME.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C5.8 00:21   12975 GOES16  
M2.2 01:11   12975 GOES16  
M1.1 01:58   12975 GOES16 SWPC wrongly attributed this flare to AR 12974. While there was a simultaneous event in AR 12974, the event in AR 12975 was far larger
C5.5 03:39   12975 GOES16  
C5.2 03:49   12975 GOES16  
C8.6 03:59   12975 GOES16  
C2.7 05:47   12975 GOES16  
C2.4 06:28   12975 GOES16  
C3.5 07:05   12975 GOES16  
C3.3 07:47   12975 GOES16  
C3.4 08:10   12975 GOES16  
C3.1 09:01   12975 GOES16  
M1.0 09:38   12975 GOES16  
C4.7 10:17   12975 GOES16  
C2.0 11:34   12975 GOES16  
C2.2 12:33   S7458 GOES16  
C4.3 14:47 N14W21 12975 GOES16  
C3.9 15:18 S24E65 S7458 GOES16  
C2.3 15:56   S7458 GOES16  
C2.1 17:12   S7458 GOES16 Simultaneous event in AR 12975
C4.7 17:45   12975 GOES16  
C3.3 19:46   S7458 GOES16 Wrongly attributed to AR 12975 by SWPC
C2.1 20:02   12975 GOES16  
C3.5 20:32   12975 GOES16  
M1.6 21:52   12975 GOES16  
C6.7 22:58   S7458 GOES16  

Coronal mass ejections (CMEs)

March 27, 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

Quiet to major storm conditions are possible on March 30-31 if the March 28 CMEs impact Earth, quiet to active is likely on April 1.

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
12973 2022.03.19
2022.03.20
      N19W76            
S7438 2022.03.19       N17W47            
12974 2022.03.21
2022.03.22
1 6 1 S19W27 0000 AXX CRO

location: S19W25

area: 0015

S7443 2022.03.21       S24W33            
12975 2022.03.22
2022.03.23
30 55 34 N13W24 0300 DHC EAC

beta-gamma-delta

area: 0480

12976 2022.03.22
2022.03.24
9 25 12 N14W03 0500 EKO EKO

location: N15W07

S7448 2022.03.25       N18W34            
12979 2022.03.25
2022.03.28
2 9 6 S19W03 0030 AXX CRO area: 0020
12977 2022.03.26
2022.03.27
1 2   N18W36 0010 AXX BXO area: 0002
S7453 2022.03.27       S27W35            
12978 2022.03.27
2022.03.27
8 14 7 S20E56 0310 DHO EHO

beta-gamma

location: S17E52

area: 0590

S7455 2022.03.27   2 1 S23W73 0005   HRX  
12980 2022.03.27
2022.03.28
3 9 4 N08W42 0010 BXO BXO area: 0020
S7457 2022.03.27       N25E16            
S7458 2022.03.27   23 11 S24E58 0050   DRI beta-gamma
S7459 2022.03.27       N40E08          
S7460 2022.03.28       S33W40            
S7461 2022.03.28       N20E25          
S7462 2022.03.28   4 1 S16E24 0008   BXO  
S7463 2022.03.28       S42E36          
S7464 2022.03.28       S28E33          
S7465 2022.03.29   3 1 S04W38 0025   CRO   SC24 group
S7466 2022.03.29   1   N21W30 0001   AXX    
S7467 2022.03.29   4 2 S19E11 0007   BXO    
S7468 2022.03.29   1   S19E87 0070   HSX    
Total spot count: 54 158 80  
Sunspot number: 124 298 190  (total spot count + 10 * number of spotted regions)
Weighted SN: 84 203 120  (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): 136 164 152  

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
2022.03 114.7 (1)   60.0 (2A) / 68.4 (2B) / 88.8 (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.