Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 28, 2020 at 17:25 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 (January 1, 2020)
Solar cycle Solar cycles 23-24 (January 1, 2020) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (January 1, 2020) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012]
  Comparison of cycles 21, 22, 23 and 24 (January 1, 2020) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (January 1, 2020) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (December 27, 2019) Cycle 25 spots (December 25, 2019)

Recent activity

The geomagnetic field was very quiet on January 27. Solar wind speed at SOHO ranged between 299 and 308 km/sec (partial data set only).

Solar flux at 20h UT on 2.8 GHz was 72.9 (increasing 2.4 over the previous solar rotation). The average 90 day 10.7 flux at 1 AU was 69.0 (The centered average 90 day SF at 1 AU reached a low of 67.77 on December 9, 2018. The centered 1 year average SF at 1 AU reached a minimum of 69.46 on April 27, 2019. The current 1 year average 1 AU SF is 69.71). The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.9). Three hour interval K indices: 01100000 (planetary), 11200121 (Boulder)

The background x-ray flux is at the class A1 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 3 active regions using 2K resolution (SN: 42) and in 2 active regions using 1K resolution (SN: 26) SDO/HMI images.

Region 12757 [N02W14] decayed further and was quiet.

Spotted regions not observed (or interpreted differently) by SWPC:
S6357 [S30E50] was quiet and stable.
New region S6359 [S29W47] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
           

Coronal mass ejections (CMEs)

January 25-27: 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]

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 latitudes is good. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on January 28-31.

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 numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. 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.

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 Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
S6350 2020.01.20       N04W44            
S6351 2020.01.21       N18W48            
12757 2020.01.23
2020.01.24
2 8 4 N05W14 0100 CSO CSO area: 0080

location: N02W14

S6355 2020.01.24       S31W24            
S6356 2020.01.25       N30E15            
S6357 2020.01.25   3 2 S30E50 0006   BXO  
S6358 2020.01.26       S30E39          
S6359 2020.01.27   1   S29W47 0001   AXX    
Total spot count: 2 12 6  
Sunspot number: 12 42 26  (total spot count + 10 * number of spotted regions)
Weighted SN: 7 17 11  (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): 13 23 21 k * (sunspot number)
As of May 7, 2016: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.80 for MSN 1K (MSN=Magnetic Sunspot Number)

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 (cycle 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)
2018.08 69.1 70.8 8.7 6.7 (-0.3) 8.98
2018.09 68.2 69.0 3.3 6.5 (-0.2) 8.91
2018.10 69.6 69.1 4.9 6.8 (+0.3) 6.49
2018.11 68.9 67.4 4.9 6.7 (-0.1) 5.78
2018.12 70.0 67.8 3.1 6.0 (-0.7) 6.10
2019.01 71.5 69.2 7.7 5.4 (-0.6) 5.89
2019.02 70.6 68.9 0.8 5.0 (-0.4) 6.88
2019.03 71.6 70.8 9.4 4.6 (-0.4) 6.12
2019.04 72.4 72.9 9.1 4.3 (-0.3) 6.06
2019.05 71.3 72.8 9.9 3.9 (-0.4) 6.98
2019.06 68.1 70.3 1.2 3.7 (-0.2) 4.26
2019.07 67.1 69.3 0.9 (3.5 projected, -0.2)
The months
July-November 2019 are
solar minimum candidates
5.36
2019.08 67.0 68.7 0.5 (3.6 projected, +0.1) 6.79
2019.09 67.9 68.7 1.1 (3.8 projected, +0.2) 9.81
2019.10 67.4 67.0 0.4 (3.8 projected, 0.0) 7.53
2019.11 70.2 68.7 0.5 (3.8 projected, 0.0) 4.19
2019.12 70.8 68.6 1.6 (4.3 projected, +0.5) 3.22
2020.01 (71.9)   4.5 (2A) / 5.2 (2B) / 7.9 (2C) (5.5 projected, +1.2) (4.0)
2020.02       (7.2 projected, +1.7)  
2020.03       (8.6 projected, +1.4)  
2020.04       (10.1 projected, +1.5)  
2020.05       (11.6 projected, +1.5)  
2020.06       (13.3 projected, +1.7)  

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
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.

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.