Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 21, 2022 at 07:35 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 20. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 95 - decreasing 2.8 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 88.63). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.5). Three hour interval K indices: 34211103 (planetary), 33311212 (Boulder), 44111005 (Andenes).

The background x-ray flux is at the class B3 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 124) and in 5 active regions using 1K resolution (SN: 71) SDO/HMI images.

Region 12967 [N17W45] was quiet and stable.
Region 12971 [N18E03] reemerged with tiny spots and produced a C4 flare. No obvious CME was observed following this event, however, there were other CMEs later on from sources behind the east limb.
Region 12972 [S28E05] gained a few spots and was quiet.
New region 12973 [N19E47] emerged on March 19 and was numbered by SWPC the next day.

Spotted regions not observed (or interpreted differently) by SWPC:
S7433 [S22W19] was quiet and stable.
S7437 [N22W01] was quiet and stable.
S7438 [N15E66] was quiet and stable.
New region S7439 [N17W05] emerged before noon with tiny spots.

AR S7441 [S18E90] rotated partly into view at the southeast limb early on March 21. C1 flares: C1.2 @ 18:11 UT

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.6/1F 07:45 N16E14 12971 GOES16 fast EIT wave, weak type II radio sweep

Coronal mass ejections (CMEs)

March 18, 20: No obviously Earth directed CMEs were observed in available LASCO imagery.
March 19: A filament eruption began near AR 12972 at approximately 09:26 UT and appears to have been associated with a faint partial halo CME. Effects from this CME could reach Earth on March 22.

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 (CH1069) rotated across the central meridian on March 19-20.

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

The geomagnetic field is expected to be mostly quiet on March 21-22. If the March 19 CME reaches Earth, quiet to active conditions could occur during the latter half of March 22 and on March 23. A high speed stream associated with CH1069 could cause quiet to active conditions on March 23.

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
12965 2022.03.08 2     N26W82 0040 CAO     rotated out of view before noon

location: N22W91

S7418 2022.03.10       S16W37            
12968 2022.03.10
2022.03.13
      S23W62           location: S21W48

SWPC location is actually AR 12970

12967 2022.03.11
2022.03.12
  3 1 N17W49 0006   AXX

location: N17W45

12970 2022.03.12
2022.03.14
      S23W66          

location: S22W61

S7427 2022.03.15       S14W46            
S7429 2022.03.15       N12W48            
12971 2022.03.15
2022.03.17
  3   N16E03 0004   BXO   location: N18E03
S7433 2022.03.18   2 1 S22W19 0006   HRX  
S7434 2022.03.18       S09W38            
12972 2022.03.19
2022.03.19
4 21 13 S28E05 0040 BXO DRI area: 0070
12973 2022.03.19
2022.03.20
4 10 5 N19E45 0040 BXO CRO location: N19E47

area: 0020

S7437 2022.03.19   1 1 N22W01 0003   AXX  
S7438 2022.03.19   2   N15E66 0003   AXX  
S7439 2022.03.20   2   N17W05 0003   AXX  
S7440 2022.03.20       S12W22          
S7441 2022.03.21       S18E90          
Total spot count: 10 44 21  
Sunspot number: 40 124 71  (total spot count + 10 * number of spotted regions)
Weighted SN: 15 53 30  (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): 44 68 57  

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)   45.5 (2A) / 70.6 (2B) / 76.1 (2C) (67.9 projected, +5.5) (10.5)
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.