Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 30, 2015 at 04:20 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update January 1, 2015)] [Cycle 24 progress (last update January 1, 2015) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2015)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2015)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 3, 2015)]

[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated January 25, 2015]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to active on January 29. Solar wind speed at SOHO ranged between 352 and 412 km/s.

Solar flux at 20h UTC on 2.8 GHz was 171.8 (increasing 26.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 147.4. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.8). Three hour interval K indices: 21112242 (planetary), 20122233 (Boulder).

The background x-ray flux is at the class B9 level.

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 280) and 8 active regions using 1K resolution (SN: 193) SDO images on the visible solar disk.

Region 12268 [S10W17] has a weak magnetic delta in a central penumbra. The leader spot decayed. Further minor M class flares are possible.
Region 12271 [N18W43] lost a few spots and was mostly quiet.
Region 12272 [N12E19] was quiet and stable.
Region 12273 [S03W41] decayed slowly and quietly.
Region 12275 [S17W52] decayed slowly and quietly.
Region 12276 [S07E13] decayed slowly and quietly.
Region 12277 [N09E65] displayed no major changes and remains capable of producing M class flares, maybe even a major flare.
New region 12278 [S08E25] rotated into view on January 25 and was numbered by SWPC 4 days later.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C3.2 02:52 N07E72 12277  
C4.1 03:13 N07E72 12277  
C2.6 03:52 N07E71 12277  
C3.1 04:33 N07E71 12277  
C8.2/1N 05:23 S13W06 12268  
C2.9 09:57 N07E62 12277  
C2.1 10:43 N10E68 12277  
M2.1/1B 11:42 S12W06 12268  
C7.6 12:26   12277  
C2.4 13:33   12277  
C2.2 14:16   12268  
C5.0 18:15   12277  
C6.4 (LDE) 19:53   12268  
C8.4/1N 23:47 N07E61 12277  

Coronal mass ejections (CMEs)

January 27-29: No obviously Earth directed CMEs were observed in 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]

An extension of the southern polar coronal hole could be associated with a co-rotating interaction region transiting the central meridian on January 29-30.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on January 30 - February 1 with a chance of active to minor storm conditions on January 31 and February should a disturbance associated with a co-rotating interaction region arrive.

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) 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 Date numbered
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12267 2015.01.18
2015.01.19
      N18W77           plage
12269 2015.01.19
2015.01.22
      N07W66        

plage

12268 2015.01.21
2015.01.22
35 61 32 S10W17 0510 FHC FKC beta-gamma-delta

area: 0650

12270 2015.01.22
2015.01.23
      S18W29           plage
S4168 2015.01.23       S10W53           plage
12271 2015.01.23
2015.01.25
20 24 14 N17W44 0170 DAC EAI

beta-gamma

area: 0310

S4172 2015.01.24       S24W41           plage
12278 2015.01.25
2015.01.29
6 19 13 S09E24 0010 BXO CRI area: 0030
12272 2015.01.25
2015.01.26
2 5 3 N12E18 0020 HAX CAO  
12273 2015.01.25
2015.01.26
5 11 5 S04W41 0040 CAO CAO  
12274 2015.01.25
2015.01.26
      S03W50           plage
12275 2015.01.26 10 15 10 S17W53 0140 DAO DAO  
S4179 2015.01.26       N17W54           plage
S4180 2015.01.26       N23W32           plage
12276 2015.01.27
2015.01.28
6 10 5 S07E12 0010 BXO BXO area: 0015
S4182 2015.01.27       N17W32         plage
12277 2015.01.27
2015.01.28
17 55 31 N07E61 0260 FHC FKC beta-gamma

area: 0650

location: N09E65

S4185 2015.01.28       S23W18         plage
Total spot count: 101 200 113  
Sunspot number: 181 280 193  (total spot count + 10 * number of spotted regions)
Weighted SN: 141 243 156  (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): 109 98 106 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1)
(likely solar max)
7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 79.7 (-0.8) 6.72
2014.07 137.4 141.8 72.5 (78.6 projected, -1.1) 4.50
2014.08 124.7 127.9 74.7 (76.2 projected, -2.4) 7.71
2014.09 146.6 148.1 87.6 (73.0 projected, -3.2) 9.78
2014.10 153.4 152.9 60.6 (70.5 projected, -2.5) 8.96
2014.11 154.8 151.4 70.1 (68.8 projected, -1.7) 9.33
2014.12 158.7 153.8 78.0 (67.7 projected, -1.1) 11.24
2015.01 140.9 (1)   90.1 (2A) / 96.3 (2B) / 75.6 (2C) (66.5 projected, -1.2) (9.1)

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). The official WDC-SILSO international sunspot number is typically 30-50% lower. 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.

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 the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.