Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 5, 2023 at 14:50 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 3, 2023)
Solar cycle Solar cycles 23-25 (March 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (March 1, 2023) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (July 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (March 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (March 1, 2023) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (January 21, 2023) 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 4 under the influence of a high speed stream from CH1133. Solar wind speed at SOHO ranged between 609 and 803 km/sec. The high latitude magnetometer at Andenes recorded quiet to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 181.6 - increasing 37.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 135.86). The Potsdam WDC planetary A index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 15.5). Three hour interval K indices: 33332234 (planetary), ******** (Boulder), 54432346 (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: 290) and in 12 active regions using 1K resolution (SN: 177) SDO/HMI images.

Region 13238 [N08W02] developed slowly and quietly.
Region 13239 [N32E18] was quiet and stable.
Region 13240 [S18E22] was quiet and stable.
Region 13241 [N28E31] was quiet and stable.
Region 13242 [N10E38] developed slowly and could produce M class flares.
Region 13243 [N18W47] developed slowly and was mostly quiet.
Region 13244 [S22W33] was quiet and stable.
Region 13245 [S23E62] was mostly quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8327 [S09E06] developed slowly and quietly.
S8331 [S30E02] was quiet and stable.
New region S8333 [N28W07] emerged with a tiny spot.-
New region S8334 [N22E81] rotated into view with a mature spot.
New region S8335 [N22E37] emerged with tiny spots.
New region S8336 [S08E46] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C4.2 00:11   13234 GOES16  
C5.3/2N 02:26   13242 GOES16  
C3.9 05:00 N10E49 13242 GOES16  
M1.0 07:10 N17W39 13243 GOES16  
C5.6/2N 07:26 N09E44 13242 GOES16  
C6.7 08:24   13234 GOES16  
C4.9 09:28   13245 GOES16  
C2.9 10:34   13242 GOES16  
C4.1 12:00   13242 GOES16  
C4.6 13:17   S8334 GOES16  
C6.0 13:26   13234 GOES16  
M1.2/1F 13:42   13242 GOES16  
C4.8/1F 14:40   13242 GOES16  
C9.0 15:12   13234 GOES16  
M5.2 15:57   13234 GOES16 moderate type II and IV radio sweeps, full halo CME
C9.6 17:15   13242 GOES16  
C4.8 19:57   13234 GOES16  
C6.5 20:31   13234 GOES16  
C4.2 22:10   13243 GOES16  
C3.3 23:40   13242 GOES16  

Coronal mass ejections (CMEs)

March 2-4: No obviously Earth directed CMEs were observed.

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 (CH1133) rotated across the central meridian on March 1-3.

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 5-6 due to effects from CH1133, isolated minor storm intervals are possible. Quiet to unsettled is possible on March 7-8.

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
13237 2023.02.23
2023.02.24
      S08W79          

real location: S12W82

S8310 2023.02.25       S26W47            
13244 2023.02.25
2023.03.03
2 11 5 S22W33 0020 HRX CRI  
S8313 2023.02.25       N18W56            
13238 2023.02.26
2023.02.27
3 15 6 N09W05 0080 HSX DAO location: N08W02
S8316 2023.02.27       N18W57            
13239 2023.02.27
2023.02.28
1 8 2 N31E14 0100 HSX CAO location: N32E18

area: 0160

S8318 2023.02.27       S29W29            
13241 2023.02.28
2023.03.01
1 5 2 N27E32 0060 HSX HSX

location: N28E31

13240 2023.02.28
2023.03.01
6 13 2 S16E14 0010 BXO BXO area: 0020

location: S18E22

S8321 2023.02.28       N41W23            
13242 2023.03.01
2023.03.02
16 40 18 N10E39 0140 CAI EAI beta-gamma

area: 0240

location: N10E38

13243 2023.03.01
2023.03.03
12 24 9 N18W51 0090 CAO DAI area: 0170

location: N18W47

S8325 2023.03.01       N17W28            
S8326 2023.03.02       S20W02            
S8327 2023.03.02   15 7 S09E06 0050   DRI  
13245 2023.03.02
2023.03.03
1 4 2 S23E60 0120 HSX HKX area: 0360
S8330 2023.03.03       S17E51          
S8331 2023.03.03   7   S30E02 0010   AXX  
S8332 2023.03.03       N27W28          
S8333 2023.03.04   1 1 N28W07 0003   AXX    
S8334 2023.03.04   1 1 N22E81 0070   HSX    
S8335 2023.03.04   3 2 N22E37 0007   BXO    
S8336 2023.03.04   3   S08E46 0007   BXO    
Total spot count: 42 150 57  
Sunspot number: 122 290 177  (total spot count + 10 * number of spotted regions)
Weighted SN: 75 196 103  (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): 134 160 142  

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 (SC24 solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(SC24 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
2021.08 77.7 79.7 22.0 35.4 (+4.0) 6.19
2021.09 87.0 88.2 51.3 40.2 (+4.8) 6.33
2021.10 88.9 88.3 37.4 45.2 (+5.0) 7.38
2021.11 86.2 84.4 34.8 50.8 (+5.6) 9.83
2021.12 103.0 99.8 67.5 55.9 (+5.1) 6.40
2022.01 103.8 100.5 55.3 60.1 (+4.2) 8.92
2022.02 109.1 106.5 60.9 64.7 (+4.6) 10.46
2022.03 117.0 115.8 78.6 68.7 (+4.0) 10.20
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.2 (+4.2) 7.48
2022.06 116.1 119.8 70.3 80.9 (+3.7) 8.20
2022.07 125.4 129.5 91.4 86.5 (+5.6) 9.51
2022.08 114.2 117.1 74.6 92.3 (+5.8) 10.92
2022.09 135.1 136.5 96.0 (97.0 projected, +4.7) 12.18
2022.10 133.5 132.7 95.4 (100.2 projected, +3.2) 11.16
2022.11 123.4 120.7 77.6 (103.0 projected, +2.8) 9.33
2022.12 147.9 143.4 113.1 (107.8 projected, +4.8) 10.99
2023.01 182.4 176.6 143.6 (113.8 projected, +6.0) 8.73
2023.02 167.2 163.2 110.9 (118.9 projected, +5.1) 14.6
2023.03 172.0 (1)   14.5 (2A) / 112.0 (2B) / 152.9 (2C) (122.0 projected, +3.1) (13.4)
2023.04       (127.4 projected, +5.4)  
2023.05       (133.2 projected, +5.8)  
2023.06       (136.4 projected, +3.2)  
2023.07       (135.9 projected, -0.5)  
2023.08       (136.9 projected, +1.0)  
2023.11       (142.5 projected max SC25)  

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.