Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 2, 2022 at 11:55 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 1, 2022)
Solar cycle Solar cycles 23-25 (February 1, 2022) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (February 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 (February 1, 2022) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (February 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 unsettled on February 1. The high latitude magnetometer at Andenes recorded quiet to active levels. A solar wind shock was observed at DSCOVR at 21:37 UT, the arrival of the January 29 CME. The associated disturbance was much weaker than expected as the interplanetary magnetic field has been predominantly northwards since 1 hour after the initial shock.

Solar flux density measured at 20h UT on 2.8 GHz was 128.6 - increasing 44.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 84.20). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.0). Three hour interval K indices: 22111103 (planetary), 12112213 (Boulder), 31100005 (Andenes).

The background x-ray flux is at the class B8 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 211) and in 6 active regions using 1K resolution (SN: 121) SDO/HMI images.

Region 12934 [S24W88] rotated quietly to the southwest limb.
Region 12936 [N17W35] lost a few spots and was mostly quiet. C1 flares: C1.2 @ 19:16 UT
Region 12938 [N18W11] decayed slowly and quietly.
Region 12939 [S15E49] produced C flares towards the end of the day and was in slow decay.
Region 12940 [N17E48] gained spots and was unstable. An M class flare is possible. C1 flares: C1.2 @ 02:57 (wrongly attributed to AR 12936 by SWPC), C1.3 @ 05:37, C1.8 @ 07:14, C1.6 @ 08:50, C1.8 @ 11:26, C1.0 @ 17:33, C1.4 @ 21:08 UT.

Spotted regions not observed (or interpreted differently) by SWPC:
S7323 [S26W03] reemerged with tiny spots.
S7328
[S26E46] reemerged with tiny spots.
New region S7331 [N27E32] emerged with a tiny spot.
S7332 [N15W17] developed further as SWPC failed to observe that this new region is not part of AR 12938.
New region S7333 [S13E30] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C8.6 07:36   12940 GOES16  
C2.4 10:27   12940 GOES16  
C2.8 12:19   12940 GOES16  
C2.2 13:11   12940 GOES16  
C6.5 15:27   12940 GOES16  
C9.0 22:36   12939 GOES16  

Coronal mass ejections (CMEs)

January 30 - February 1: 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 recurrent trans equatorial coronal hole (CH1058) will likely rotate across the central meridian on February 1-2.

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 quiet to active on February 2 due to CME effects and quiet to unsettled on February 3-4. On February 5-6 quiet to active conditions are likely due to effects from CH1058.

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
12934 2022.01.19
2022.01.20
1 1 1 S23W91 0120 HSX HSX

location: S24W87

12937 2022.01.20
2022.01.25
      S20W81         location: S21W75
12936 2022.01.23
2022.01.25
9 38 20 N16W35 0670 EKI EKI beta-gamma
12938 2022.01.25
2022.01.26
3 4   N18W20 0020 CRO AXX location: N18W11

area: 0008

SWPC has failed to observe AR S7332 and uses data from that region

S7320 2022.01.28       N24W35            
S7321 2022.01.29       N35W50            
S7322 2022.01.29       S32W42            
S7323 2022.01.29   4 1 S26W03 0012   AXX    
12939 2022.01.29
2022.01.30
7 7 3 S15E47 0500 DHO EHO

area: 0310

location: S15E49

12940 2022.01.30
2022.01.30
18 39 27 N22E46 0410 DKI EAI

location: N17E48

S7326 2022.01.30       N29W54            
S7327 2022.01.30       N17E37            
S7328 2022.01.30   7   S26E46 0015   BXO    
S7329 2022.01.30       S17W02|            
S7330 2022.01.30       S06W01            
S7331 2022.01.31       N27E19          
S7332 2022.01.31   20 9 N15W17 0070   DRI  
S7333 2022.02.01   1   S26W03 0001   AXX  

 

Total spot count: 38 121 61  
Sunspot number: 88 211 121  (total spot count + 10 * number of spotted regions)
Weighted SN: 76 154 94  (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): 110 116 97  

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
2020.07 69.5 71.8 6.1 9.0 (+1.1) 4.28
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 (36.2 projected, +4.8) 6.19
2021.09 87.0 88.2 51.3 (42.3 projected, +6.1) 6.33
2021.10 88.9 88.3 38.1 (46.7 projected, +4.4) 7.38
2021.11 86.2 84.4 35.0 (51.3 projected, +4.6) 9.83
2021.12 103.0 99.8 67.6 (57.2 projected, +5.9) 6.40
2022.01 103.8 100.5 54.0 (60.8 projected, +3.6) 8.9
2022.02 128.6 (1)   3.1 (2A) / 88 (2B) / 68.7 (2C) (65.5 projected, +4.7) (6.0)
2022.03       (71.0 projected, +5.5)  
2022.04       (76.1 projected, +5.1)  
2022.05       (82.6 projected, +6.5)  
2022.06       (88.4 projected, +5.9)  
2022.07       (95.7 projected, +7.3)  

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.