Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 1, 2022 at 09:55 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 January 31. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 129.5 - increasing 44.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 84.06). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 8.9). Three hour interval K indices: 33232212 (planetary), 23242222 (Boulder), 43322333 (Andenes).

The background x-ray flux is at the class C1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 197) and in 7 active regions using 1K resolution (SN: 128) SDO/HMI images.

Region 12934 [S24W75] was quiet and stable.
Region 12936 [N17W21] decayed slowly in the central section, however, both the leading and trailing penumbra are large. Although the region was mostly quiet, there is some polarity intermixing and the potential to produce major flares remains.
Region 12937 [S21W62] was quiet and stable.
Region 12938 [N19E04] was quiet and stable.
Region 12939 [S15E61] was mostly quiet. The region has minor polarity intermixing and M class flaring potential.
New region 12940 [N17E61] rotated into view on January 30 and was observed by SWPC the next day. The region is by far the most active on the visible disk and could produce M class flares. The region is developing and gained spots and area. C1 flares: C1.6 @ 00:23, C1.4 @ 02:16 (wrongly attributed to AR 12936 by SWPC), C1.0 @ 04:42, C1.1 @ 10:55, C1.9 @ 20:09, C1.0 @ 21:59, C1.8 @ 22:07, C1.2 @ 23:34 UT

Spotted regions not observed (or interpreted differently) by SWPC:
New region S7331 [N27E32] emerged with a tiny spot.
New region S7332 [N16W02] was observed with several spots as new flux emerged to the west of AR 12938.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.7 03:50   12940 GOES16  

Coronal mass ejections (CMEs)

January 30-31: No obviously Earth directed CMEs were observed in available LASCO imagery.
January 29: The long duration M1.1 event in AR 12936 late in the day was associated with an asymmetrical halo CME. The fastest parts of the CME was observed off the northeast limb. The CME could reach Earth during the latter half of February 1 or on February 2.

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 unsettled on February 1. Sometime during the latter half of February 1 or early on February 2 the CME observed late on January 29 is expected to reach Earth causing unsettled to major 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
12934 2022.01.19
2022.01.20
1 1 1 S25W77 0110 HSX HSX

location: S24W75

12937 2022.01.20
2022.01.25
  3   S20W67 0003   AXX location: S21W62
12936 2022.01.23
2022.01.25
22 42 24 N16W22 0750 EHI EKI beta-gamma

location: N17W21

12935 2022.01.24
2022.01.24
3     N27W86 0010 BXO    

spotless

12938 2022.01.25
2022.01.26
2 12 4 N18W01 0010 AXX BXO location: N19E04

area: 0020

S7320 2022.01.28       N24W22            
S7321 2022.01.29       N35W37            
S7322 2022.01.29       S32W29            
S7323 2022.01.29       S26E14          
12939 2022.01.29
2022.01.30
7 17 6 S15E62 0280 DHO EKO

beta-gamma

area: 0400

12940 2022.01.30
2022.01.30
5 29 14 N17E61 0160 CSO DAC beta-gamma

area: 0280

S7326 2022.01.30       N29W41          
S7327 2022.01.30       N17E50          
S7328 2022.01.30       S26E59          
S7329 2022.01.30       S17E11          
S7330 2022.01.30       S06E12          
S7331 2022.01.31   1 1 N27E32 0003   AXX    
S7332 2022.01.31   12 8 N16W02 0030   CRO  

 

Total spot count: 40 117 58  
Sunspot number: 100 197 128  (total spot count + 10 * number of spotted regions)
Weighted SN: 80 150 91  (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): 110 108 102  

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 (1)   (2A/2B) / 66.2 (2C) (65.5 projected, +4.7)  
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.