Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 29, 2015 at 05:30 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 unsettled on January 28. Solar wind speed at SOHO ranged between 393 and 486 km/s.

Solar flux at 20h UTC on 2.8 GHz was 159.3 (increasing 22.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 146.9. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.0). Three hour interval K indices: 32321101 (planetary), 21331111 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 302) and 11 active regions using 1K resolution (SN: 227) SDO images on the visible solar disk.

Region 12268 [S10W03] has polarity intermixing in the trailing spot section. Further minor M class flares are possible.
Region 12269 [N07W50] decayed slowly and quietly.
Region 12271 [N17W30] developed slowly and has minor M class flare potential.
Region 12272 [N12E32] decayed slowly and quietly.
Region 12273 [S03W27] decayed slowly and quietly.
Region 12275 [S17W39] decayed slowly and quietly.
New region 12276 [S07E27] emerged on January 27 and was numbered by SWPC the next day.
New region 12277 [N09E79] rotated partly into view on January 27 and was numbered by SPWC the following day. It is currently uncertain if the trailing spots is a separate region. A major flare is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4174 [S08E38] gained spots and was quiet.
S4182 [N17W19] was quiet and stable.
New region S4185 [S23W05] emerged with a single spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C4.7/1F 01:28 S11E12 12268  
M1.4/2N 04:41 S09E09 12268  
C9.8 05:30   12268  
C2.7 10:43   12268  
C2.5 13:12   12277  
C2.2 18:35 S13E02 12268  
M1.0 21:37 N08E73 12277  

Coronal mass ejections (CMEs)

January 26-28: 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 corotating interaction region rotating across the central meridian on January 29.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle 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 January 29-31.

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) 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
      N18W63           plage
12269 2015.01.19
2015.01.22
1 2 1 N07W51 0010 AXX BXO

area: 0004

12268 2015.01.21
2015.01.22
29 57 45 S10W05 0410 FKC FKC beta-gamma

area: 0750

12270 2015.01.22
2015.01.23
      S18W15           plage
S4166 2015.01.22       S27W49           plage
S4167 2015.01.22       N02W58           plage
S4168 2015.01.23       S10W40           plage
12271 2015.01.23
2015.01.25
10 34 16 N18W30 0110 DAI DAC

area: 0240

S4172 2015.01.24       S24W28           plage
S4174 2015.01.25   19 7 S08E38 0045   CRI  
12272 2015.01.25
2015.01.26
1 3 1 N12E31 0030 HAX CRO  
12273 2015.01.25
2015.01.26
4 10 5 S03W26 0050 CAO CAO  
12274 2015.01.25
2015.01.26
      S03W35           plage
12275 2015.01.26 11 27 12 S17W40 0200 DAI DAO  
S4179 2015.01.26       N17W41           plage
S4180 2015.01.26       N23W19           plage
12276 2015.01.27
2015.01.28
3 14 9 S07E25 0010 BXO DRI area: 0050
S4182 2015.01.27   3 2 N17W19 0007   BXO  
12277 2015.01.27
2015.01.28
1 32 18 N07E67 0030 HAX FKC beta-gamma

area: 0600

location: N09E79

S4184 2015.01.27       N22W58         plage
S4185 2015.01.28   1 1 S23W05 0003   AXX  

 

Total spot count: 60 192 117  
Sunspot number: 140 302 227  (total spot count + 10 * number of spotted regions)
Weighted SN: 95 236 161  (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): 84 106 125 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
2015.01 139.8 (1)   84.3 (2A) / 93.3 (2B) / 74.8 (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.