Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 11, 2023 at 12:30 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 quiet to active on February 10. Solar wind speed at SOHO ranged between 425 and 537 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.

Solar flux density measured at 20h UT on 2.8 GHz was 207.8 - decreasing 20.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 131.87). The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 14.9). Three hour interval K indices: 43233234 (planetary), 32323333 (Boulder), 54333255(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 17 active regions using 2K resolution (SN: 396) and in 15 active regions using 1K resolution (SN: 268) SDO/HMI images.

Region 13209 [N20W37] developed slowly and quietly.
Region 13213 [N31W37] gained some spots, however, the main penumbra decreased in area and only a small magnetic delta remained in the intermediate spot section. There is still a chance of a major flare.
Region 13214 [N12W20] developed slowly and was mostly quiet. Positive polarity flux began to emerge in the western parts of the trailing spots. An M class flare is possible.
Region 13215 [N22E03] decayed slowly and quietly.
Region 13216 [N25E18] was mostly quiet and stable.
Region 13217 [S11E48] is still compact and has a magnetic delta structure. A major flare is possible.
Region 13218 [N11E33] was quiet and stable.
Region 13219 [S06E42] developed slowly and was mostly quiet.
Region 13220 [S14E64] was mostly quiet and stable.
Region 13221 [N15E61] was quiet and stable.
New region 13222 [N30W68] emerged with several spots and could produce C flares as there is some polarity intermixing.

Spotted regions not observed (or interpreted differently) by SWPC:
S8238 [S23W28] decayed slowly and quietly.
S8250 [S26W08] was quiet and stable.
S8258 [N08W66] developed and has C class flare potential. SWPC has repositioned old AR 13208 (originally 7 degrees further north and spotless plage) to this region.
S8260 [S13E04] decayed slowly and quietly.
S8264 [S10E57] was quiet and stable.
New region S8266  [N18E45] was observed with a tiny spot in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.4 00:26 N31W23 13213 GOES16  
C2.6 01:55   13217 GOES16  
C2.6 02:13   13213 GOES16  
C2.7 02:28   13217 GOES16  
M3.7/2N 03:03 N29W25 13213 GOES16 moderate type II and weak type IV radio sweeps. CME
C9.3/1F 05:46 S10E62 13217 GOES16  
M1.4 08:05 N31W27 13213 GOES16  
C5.7 08:52 S10E55 13217 GOES16  
C5.5 09:06 S12E54 13217 GOES16 incorrectly attributed to AR 13219 by SWPC
C4.1 10:29   13217 GOES16 incorrectly attributed to AR 13208 by SWPC
C9.6 10:50 S11E54 13217 GOES16  
C3.5 14:22   13214 GOES16  
M1.1 14:55   13213 GOES16  
M1.6 16:00   13213 GOES16  
C4.7 17:50   13220 GOES16  
C3.8 18:44   13222 GOES16  
C3.4 20:07   13213 GOES16  
C5.3 22:25 N28W38 13213 GOES16  
M1.2/1N 22:41 S18E63 13220 GOES16  
C6.0 23:10   13217 GOES16  
C5.8 00:03   13214 GOES16 incorrectly attributed to AR 13213 by SWPC

Coronal mass ejections (CMEs)

February 8-9: No obviously Earth directed CMEs were observed in available LASCO imagery.
February 10: A large filament eruption in the southwest quadrant peaked near 09h UT and produced a partial halo CME. Components of this CME could reach Earth on February 13-15.

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]

No obvious coronal holes are currently in or near Earth facing positions.

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 to fair.

Forecast

Quiet to active geomagnetic conditions are likely on February 11-12. The February 10 CME could reach Earth on February 13 or 14 and cause unsettled to minor storm conditions.

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
13207 2023.01.29
2023.01.30
      S13W75        

 

13208 2023.02.01
2023.02.01
5     N09W66 0020 CRO      

real location: N15W63

SWPC repositioned spotless plage AR 13208 on February 9 to an emerging further further south, see AR S8258

13209 2023.02.01
2023.02.03
2 6 3 N22W38 0010 BXO CRO location: N20W22

area: 0018

location: N20W37

S8234 2023.02.01       S29W52            
S8238 2023.02.03   10   S23W28 0014   BXO  
13213 2023.02.04
2023.02.06
22 67 34 N30W39 0450 FKI FAI beta-gamma-delta

location: N31W37

S8243 2023.02.05       N28W54            
13214 2023.02.05
2023.02.06
11 31 17 N11W20 0300 DHO DKI

beta-gamma

area: 0620

13215 2023.02.05
2023.02.06
1 6 2 N22E03 0010 AXX BXO

 

13216 2023.02.05
2023.02.06
3 12 6 N24E19 0140 HSX CAO area: 0180
S8247 2023.02.05       S27W30            
S8248 2023.02.05       S23W51            
S8250 2023.02.06   11 3 S25E05 0020   BXO  
S8251 2023.02.06       N09W46            
S8254 2023.02.07       N22W28          
13218 2023.02.07
2023.02.08
2 8 3 N11E35 0010 BXO CRO

location: N11E33

13217 2023.02.07
2023.02.08
11 22 19 S11E49 0380 DKI DKC beta-gamma-delta

area: 0690

13219 2023.02.08
2023.02.09
6 12 8 S07E42 0030 CRO DRI location: S06E42

area: 0060

S8258 2023.02.08   13 9 N08W66 0080   DAI see AR 13208
S8259 2023.02.08       N18E47            
S8260 2023.02.08   4   S13E04 0007   BXO  
S8261 2023.02.08       S09W09            
13220 2023.02.09
2023.02.09
3 5 2 S15E64 0130 CSO CHO area: 0310

location: S14E64

13221 2023.02.09
2023.02.09
2 3 3 N16E62 0100 HAX HAX area: 0180

location: N15E61

S8264 2023.02.09   6 3 S10E57 0012   BXO  
13222 2023.02.10
2023.02.10
2 9 5 N35W64 0030 CRO DRI   beta-gamma

area: 0060

location: N30W68

S8266 2023.02.09   1 1 N18E45 0002   AXX    
Total spot count: 70 226 118  
Sunspot number: 190 396 268  (total spot count + 10 * number of spotted regions)
Weighted SN: 124 288 176  (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): 209 218 214  

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
2023.02 164.8 (1)   39.1 (2A) / 109.5 (2B) / 168.6 (2C) (119.2 projected, +5.0) (11.6)
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.