Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 3, 2022 at 08:50 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 active on February 2 under the influence of weak CME effects. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. Another solar wind disturbance was observed arriving at DSCOVR near 23:20 UT, apparently a magnetic cloud with slow intensification of the total field of the interplanetary magnetic field. The Bz component of the IMF is strongly southwards as I write this, minor to major storm intervals are possible.

Solar flux density measured at 20h UT on 2.8 GHz was 128.2 - increasing 34.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 84.35). The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.6). Three hour interval K indices: 43112421 (planetary), 32003421 (Boulder), 54001512 (Andenes).

The background x-ray flux is at the class B7 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 201) and in 6 active regions using 1K resolution (SN: 115) SDO/HMI images.

Region 12936 [N17W48] appeared to be in slow decay. Some growth was observed in the intermediate spots with weak polarity intermixing.
Region 12939 [S15E35] was mostly quiet and stable.
Region 12940 [N17E33] lost some area and could be slowly decaying. There is less polarity intermixing as well, and flare activity was reduced during the latter half of the day. C1 flares: C1.3 @ 03:38, C1.0 @ 07:58, C1.2 @ 08:53, C1.4 @ 15:16, C1.1 @ 17:47, C1.2 @ 20:02, C1.3 @ 21:49 UT.

Spotted regions not observed (or interpreted differently) by SWPC:
S7323 [S26W15] was quiet and stable.
S7328 [S27E32] was quiet and stable.
S7332 [N15W31] decayed slowly and quietly.
New region S7334 [N23E88] rotated partly into view. C1 flares: C1.1 @ 12:22, C1.2 @ 21:22 UT.
New region S7335 [S12W05] emerged late in the day with tiny spots.
New region S7336 [S22E35] began to emerge late in the day. This is a reversed polarities region and the region is slowly adding spots early on February 3.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.3 02:07 N16W28 12936 GOES16  
C2.7 04:43   12940 GOES16  
C3.3 05:33 N18E52 12940 GOES16 wrongly attributed to AR 12936 by SWPC
C5.5 10:04 N19E46 12940 GOES16  
C7.8 10:26 S15E27 12939 GOES16 unreported by SWPC
C2.1 15:50   12940 GOES16  
C2.0 16:38 N23E90 S7334 GOES16  

Coronal mass ejections (CMEs)

January 31 - February 2: 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. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to minor storm on February 3 due to CME effects and quiet to unsettled on February 4. On February 5-8 quiet to active conditions are likely due to effects from CH1058 and CH1059.

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
12936 2022.01.23
2022.01.25
12 36 19 N17W49 0760 DKI EKI beta-gamma
12938 2022.01.25
2022.01.26
4     N16W29 0020 CRO     location: N18W24

spotless

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

S7320 2022.01.28       N24W48            
S7322 2022.01.29       S32W55            
S7323 2022.01.29   1 1 S26W15 0004   AXX  
12939 2022.01.29
2022.01.30
3 13 7 S16E34 0300 DHO DSO

 

12940 2022.01.30
2022.01.30
16 42 21 N18E33 0320 DAO EAI

location: N17E33

S7327 2022.01.30       N17E24            
S7328 2022.01.30   6 2 S27E32 0015   AXX  
S7329 2022.01.30       S17W15            
S7330 2022.01.30       S06W14            
S7331 2022.01.31       N27E06            
S7332 2022.01.31   9 5 N15W31 0030   CRI  
S7333 2022.02.01       S26W16          
S7334 2022.02.02   1   N23E88 0140   HSX  
S7335 2022.02.02   2   S12W05 0003   BXO    
S7336 2022.02.02   1   S22E35 0002   AXX  

reversed polarities

Total spot count: 35 111 55  
Sunspot number: 75 201 115  (total spot count + 10 * number of spotted regions)
Weighted SN: 63 139 83  (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): 83 111 92  

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
2022.02 128.4 (1)   5.8 (2A) / 81.5 (2B) / 71.4 (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.