Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 8, 2023 at 07:55 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 (February 4, 2023)
Solar cycle Solar cycles 23-25 (February 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (February 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 (February 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (February 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 unsettled to active on February 7 due to effects from CH1129. Solar wind speed at SOHO ranged between 456 and 655 km/sec. The high latitude magnetometer at Andenes recorded unsettled to major storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 184.7 - decreasing 10.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 131.20). The Potsdam WDC planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 18.9). Three hour interval K indices: 44343333 (planetary), 33243322 (Boulder), 65333454 (Andenes).

The background x-ray flux was at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 16 active regions using 2K resolution (SN: 349) and in 13 active regions using 1K resolution (SN: 215) SDO/HMI images.

Region 13207 [S13W29] was quiet and stable.
Region 13209 [N19E02] decayed slowly and quietly.
Region 13210 [S15W58] was quiet and stable.
Region 13211 [S18W67] decayed slowly and was mostly quiet.
Region 13212 [S17W82] decayed quickly and was quiet.
Region 13213 [N30E02] developed further and gained a magnetic delta in the trailing spot section. The region was unstable and produced several C and M flares. Early on February 8 the region is maturing and appears to become less active. C1 flares: C1.6 @ 00:58, C1.7 @ 01:39, C1.6 @ 03:03, C1.6 @ 04:36 UT
Region 13214 [N10E19] developed slowly and was mostly quiet.
Region 13215 [N22E43] was quiet and stable.
Region 13216 [N25E57] was mostly quiet and stable.

Spotted regions not observed (or interpreted differently) by SWPC:
S8238 [S15W08] was quiet and stable.
S8243 [N28W15] was quiet and stable.
S8250 [S26E30] was quiet and stable.
New region S8253 [N13W48] emerged with a tiny spot.
New region S8254 [N23E13] emerged with tiny spots.
New region S8255 [N11E78] emerged near the east limb with tiny spots.
New region S8256 [S10E84] rotated partly into view and could produce a major flare.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 01:27   13213 GOES16 incorrectly attributed to AR 13214 by SWPC
C3.0 02:42   13216 GOES16  
C2.1 03:45   13213 GOES16  
C3.5 06:07   13213 GOES16  
C2.2 07:15 N12E36 13214 GOES16  
C3.2 08:32 N28E10 13213 GOES16  
C2.5 09:16   13213 GOES16  
C3.0 09:51 N29E10 13213 GOES16  
C2.5 12:13   S8256 GOES16  
C3.6 12:23   13213 GOES16  
C5.8 12:32   13213 GOES16  
C5.5 13:23   13213 GOES16  
M1.0 13:53   S8256 GOES16  
C5.0 15:44   13213 GOES16  
C4.4 16:10   S8256 GOES16  
C6.7 17:17   13213 GOES16  
C5.4 18:23 S16W64 13211 GOES16  
C3.8 19:14   13213 GOES16  
C4.5 19:33   S8256 GOES16 simultaneous flare in AR 13213
M1.6 20:07   13213 GOES16  
C4.5 20:58   13213 GOES16 simultaneous flare in AR 13211
C5.3 21:30   13211 GOES16  
C6.2 21:41   13211 GOES16  
M3.9 22:58   13213 GOES16  
M6.3 23:07   13213 GOES16  

Coronal mass ejections (CMEs)

February 5-7: No obviously Earth directed CMEs were observed in available LASCO imagery.

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 poorly defined trans equatorial coronal hole (CH1129) was Earth facing on February 3-4.

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 geomagnetic conditions are likely on February 8 due to effects from CH1129. Quiet to unsettled is likely on February 9-10.

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
13206 2023.01.29
2023.01.29
      S21W64        

location: S26W49

13207 2023.01.29
2023.01.30
  11 4 S14W33 0020   BXO

 

S8227 2023.01.30       N29W43            
13212 2023.01.30
2023.02.04
3 3   S16W84 0010 BXO BXO  
13208 2023.02.01
2023.02.01
      N15W29          

location: N15W24

13209 2023.02.01
2023.02.03
3 14 6 N20W01 0010 BXO CRO location: N19E02

area: 0020

S8234 2023.02.01       S29W13            
13210 2023.02.02
2023.02.03
1 7 4 S14W56 0005 AXX DRO location: S15W58

area: 0020

13211 2023.02.03
2023.02.04
3 12 5 S16W71 0050 CAO CAO location: S18W67

area: 0080

S8238 2023.02.03   17 4 S15W08 0030   BXO  
S8240 2023.02.04       S10W43            
S8241 2023.02.04       S17W45          
13213 2023.02.04
2023.02.06
9 46 27 N31W01 0080 DAI EAC beta-gamma-delta

area: 0440

location: N30E02

S8243 2023.02.05   5 3 N28W15 0010   BXO  
13214 2023.02.05
2023.02.06
8 41 19 N13E19 0120 DAO DHI beta-gamma

area: 0560

location: N10E19

13215 2023.02.05
2023.02.06
2 11 4 N23E43 0010 AXX CRO area: 0030

location: N22E43

13216 2023.02.05
2023.02.06
1 8 3 N27E53 0140 HSX DAO area: 0230

location: N25E57

S8247 2023.02.05       S27E09            
S8248 2023.02.05       S23W12            
S8249 2023.02.05       S34W26            
S8250 2023.02.06   4 3 S26E30 0010   AXX  
S8251 2023.02.06       N09W07          
S8253 2023.02.07   1   N13W48 0001   AXX    
S8254 2023.02.07   3 1 N23E13 0006   BXO    
S8255 2023.02.07   3   N11E78 0004   BXO    
S8256 2023.02.07   3 2 S10E84 0200   HAX   possibly 2 groups
Total spot count: 30 189 85  
Sunspot number: 110 349 215  (total spot count + 10 * number of spotted regions)
Weighted SN: 50 228 123  (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): 121 192 172  

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
2021.07 81.0 83.6 34.3 31.4 (+3.8) 5.51
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 (92.4 projected, +5.9) 10.92
2022.09 135.1 136.5 96.0 (97.4 projected, +5.0) 12.18
2022.10 133.5 132.7 95.4 (100.5 projected, +3.1) 11.16
2022.11 123.4 120.7 77.6 (103.4 projected, +2.9) 9.33
2022.12 147.9 143.4 113.1 (108.2 projected, +4.8) 10.99
2023.01 182.4 176.6 143.6 (114.2 projected, +6.0) 8.7
2023.02 146.8 (1)   21.9 (2A)/ 87.6 (2B) / 167.8 (2C) (119.2 projected, +5.0) (9.1)
2023.03       (122.3 projected, +3.1)  
2023.04       (127.7 projected, +5.4)  
2023.05       (133.5 projected, +5.8)  
2023.06       (136.8 projected, +3.3)  
2023.07       (136.3 projected, -0.5)  
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.