Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 14, 2023 at 07:10 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 on February 13. Solar wind speed at SOHO ranged between 327 and 400 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. SOHO MTOF data indicates the arrival of a weak CME early on February 14, probably the February 10 CME.

Solar flux density measured at 20h UT on 2.8 GHz was 189.2 - decreasing 33.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 132.59). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.5). Three hour interval K indices: 10112111 (planetary), 011121** (Boulder), 20001032 (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 19 active regions using 2K resolution (SN: 394) and in 15 active regions using 1K resolution (SN: 237) SDO/HMI images.

Region 13213 [N31W74] produced several C flares while rotating to the northwest limb.
Region 13214 [N12W58] was mostly quiet and stable.
Region 13215 [N24W34] was quiet and stable.
Region 13216 [N24W19] was quiet and stable.
Region 13217 [S12E08] decayed further and was mostly quiet.
Region 13218 [N10W08] decayed slowly and quietly.
Region 13219 [S07E00] decayed slowly and quietly.
Region 13220 [S13E25] was mostly quiet and stable.
Region 13221 [N16E21] was quiet and stable.
Region 13223 [N13E03] was quiet and stable.
Region 13224 [N21E22] was quiet and stable.
Region 13225 [S20W07] developed slowly and quietly.
New region 13226 [N10E34] emerged on February 12 and developed quickly the next day when it was numbered by SWPC. The region is compact and has multiple small magnetic deltas. Further M class flares are likely.
New region 13227 [S03E45] emerged on February 12 and was numbered by SWPC the following day.
New region 13228 [S25E13] emerged on February 11 and was slowly decaying on February 13 when it was noticed by SWPC.

Spotted regions not observed (or interpreted differently) by SWPC:
S8260 [S14W39] was quiet and stable.
S8264 [S10E18] was quiet and stable.
S8271 [S22W47] reemerged with a tiny spot.
New region S8279 [N22E43] was observed with tiny spots in an old plage area.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.3 00:04   13213 GOES16  
C3.1 00:16 S21E38 13220 GOES16  
C2.7 00:58   13226 GOES16  
C2.7 03:29   13226 GOES16  
C3.4 04:00   13213 GOES16  
C5.3 04:56   13213 GOES16  
M1.0 05:18   13226 GOES16  
C6.2 07:05   13226 GOES16  
C4.8 08:07 S25E25 13228 GOES16 simultaneous flares in ARs 13226 and 13213
C3.8 08:40   13226 GOES16  
C3.2 09:32   13226 GOES16  
C3.7 10:36   13213 GOES16 attributed to AR 13226 by SWPC
C4.5 10:47   13226 GOES16  
C4.7 11:42   13226 GOES16  
C3.7 12:11   13226 GOES16  
C3.7 13:05   13213 GOES16 incorrectly attributed to smaller, simultaneous flares in AR 13226 and 13217 by SWPC
C4.2 13:23   13213 GOES16  
C3.9 13:40   13226 GOES16  
C6.5 14:35 N11E41 13226 GOES16 simultaneous flare in AR 13213
C4.5 14:48   13226 GOES16  
C7.7 15:40   13213 GOES16 incorrectly attributed to smaller, simultaneous flare in AR 13226 by SWPC
M1.4 15:56   13226 GOES16  
C3.3 18:17   13213 GOES16  
C3.4 18:33   13226 GOES16  
C7.3 19:16   13213 GOES16  
C3.1 21:01   13226 GOES16  
C3.3 21:35   13213 GOES16  
C2.9 23:51   13226 GOES16  

Coronal mass ejections (CMEs)

February 11: An impressive filament eruption began at approximately 10:50 UT to the east of AR 13216. The main part of the CME produced was fast and not Earth directed, however, slower moving components of the CME developed into a full halo CME. Effects could reach Earth on February 14.
February 12-13: 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 northern hemisphere coronal hole (CH1130) will be Earth facing on February 14.

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 14-15 due to CME effects, isloated minor storm intervals are possible. Quiet to unsettled is expected for February 16.

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
13209 2023.02.01
2023.02.03
      N20W80           location: N20W76
13213 2023.02.04
2023.02.06
9 18 10 N28W78 0140 FAO FAI beta-gamma

location: N31W74

13214 2023.02.05
2023.02.06
6 11 7 N11W60 0360 EKO EHO

area: 0420

location: N12W58

13215 2023.02.05
2023.02.06
  1   N22W38 0001   AXX

location: N23W34

13216 2023.02.05
2023.02.06
1 9 3 N24W22 0090 HSX CSO location: N24W19

area: 0150

S8250 2023.02.06       S25W34            
S8254 2023.02.07       N22W54            
13218 2023.02.07
2023.02.08
1 8 2 N09W09 0005 AXX BXO

location: N10W08

area: 0010

13217 2023.02.07
2023.02.08
7 27 10 S10E08 0250 DHO CHO

location: S12E08

area: 0320

13219 2023.02.08
2023.02.09
2 4 2 S07W01 0010 AXX HRX location: S07E00
S8259 2023.02.08       N18E08            
S8260 2023.02.08   1   S14W39 0003   AXX  
S8261 2023.02.08       S09W48            
13220 2023.02.09
2023.02.09
1 14 3 S14E23 0150 HHX CHO area: 0270

location: S13E25

13221 2023.02.09
2023.02.09
4 20 7 N14E21 0050 CHO CRO area: 0030

location: N16E21

SWPC classification is incorrect by a large margin

S8264 2023.02.09   3   S10E18 0007   BXO  
13223 2023.02.10
2023.02.11
  5 2 N17E02 0008   AXX location: N13E03
13224 2023.02.11
2023.02.11
3 8 3 N51E21 0010 AXX HRX area: 0020

location: N21E22

SWPC location probably a typo

13225 2023.02.11
2023.02.12
6 23 11 S21W08 0030 CRO CRI area: 0050

location: S20W07

S8269 2023.02.11       S23W40            
S8271 2023.02.11   1 1 S22W47 0003   AXX    
13228 2023.02.11
2023.02.13
3 3 1 S25E14 0010 BXO BXO area: 0005
S8273 2023.02.11       N27E33            
S8274 2023.02.11       N22E41            
S8275 2023.02.11       S04W12            
13226 2023.02.12
2023.02.13
9 36 21 N11E33 0060 DAI DKC beta-gamma-delta

location: N10E34

area: 0480

13227 2023.02.12
2023.02.13
3 8 4 S03E42 0000 BXO CRO location: S03E45

area: 0035

S8278 2023.02.12       S00W14          
S8279 2023.02.13   4   N22E43 0010   BXO    
Total spot count: 55 204 87  
Sunspot number: 185 394 237  (total spot count + 10 * number of spotted regions)
Weighted SN: 113 269 152  (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): 204 217 190  

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) 8.73
2023.02 172.8 (1)   60.2 (2A) / 129.7 (2B) / 167.5 (2C) (119.2 projected, +5.0) (10.4)
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.