Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 2, 2013 at 05:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update November 2, 2013)] [Cycle 24 progress (last update November 2, 2013) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 2, 2013)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 2, 2013)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update October 9, 2013)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated November 2, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on November 1. Solar wind speed at SOHO ranged between 341 and 425 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 145.6 (increasing 39.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 118.3. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.4). Three hour interval K indices: 22111011 (planetary), 22112220 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time) spots were observed in 9 active regions in 2K resolution (SN: 192) and 8 active regions in 1K resolution (SN: 133) SDO images on the visible solar disk.

Region 11881 [S22W76] was quiet and stable.
Region 11882 [S10W33] decayed slowly and quietly.
Region 11884 [S14E02] decayed slowly and still has a magnetic delta structure in a central northern penumbra. Further M class flaring is possible. C5+ flares: C6.2 at 00:09, impulsive major M6.3/1B at 19:52 UTC.
Region 11887 [N19E37] was quiet and stable.
Region 11888 [S14W47] decayed slowly and quietly.

Spotted regions not numbered by SWPC:
S2789 [N02W33] was quiet and stable.
S2797 [S05W06] was quiet and stable.
New region S2798 [S23W02] emerged with several penumbra spots.
New region S2799 [S10E87] rotated partly into view and was barely visible at the southeast limb by the end of the day. The region could produce M flares.

Coronal mass ejections (CMEs)

October 30: An asymmetric full halo CME was observed after the X2 flare in AR 11875 at the west limb late on Oct.29 and early on Oct.30. The CME could reach Earth on November 1-2.
October 31-November 1: No obviously Earth directed CMEs were observed in LASCO or STEREO 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 coronal hole (CH592) will rotate into an Earth facing positon on October 31-November 3.

Coronal hole map

Propagation

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

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 2-3 due to CME effects. Quiet to unsettled is likely on November 4-6 due to effects from CH592.

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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% 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 STAR SDO SWPC STAR Current Previous
2K 1K
11881 2013.10.22
2013.10.24
  1 1 S20W74 0005   AXX location: S22W76
11882 2013.10.23
2013.10.24
12 11 4 S10W31 0150 DAO DSO

 

S2780 2013.10.24       S10W58           plage
S2781 2013.10.25       N26W43           plage
11883 2013.10.26       N04W12           plage

location: N02W07

11884 2013.10.26 19 55 33 S13W01 0370 EKI EAC beta-gamma-delta

area: 0520

location: S14E02

11885 2013.10.26 6     S19W02 0160 CSO       part of AR 11884
11888 2013.10.27
2013.10.31
5 13 5 S15W46 0030 CRO CRO  
11886 2013.10.28
2013.10.29
      N14W50         plage
S2789 2013.10.29   3 1 N02W33 0008   BXO  
11887 2013.10.29
2013.10.30
3 9 4 N21E37 0020 CRO DRO

location: N19E37

area: 0040

S2791 2013.10.29       N13W18           plage
S2792 2013.10.30       S10E46         plage
S2793 2013.10.30       N19W39           plage
S2794 2013.10.30       S12E29           plage
S2796 2013.10.31       N05E58         plage
S2797 2013.10.31   1 1 S05W05 0004   AXX  
S2798 2013.11.01   8 4 S23W02 0025   BXO    
S2799 2013.11.01   1   S10E87 0350   HHX    
Total spot count: 45 102 53  
Sunspot number: 95 192 133  (total spot count + 10 * number of spotted regions)
Weighted SN: 71 128 69  (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): 57 67 73 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
likely cycle 24 max
8.81
2012.07 133.9 66.5 57.8 (-1.1) 13.90
2012.08 115.4 63.0 58.2 (+0.4) 7.96
2012.09 122.9 61.4 58.1 (-0.1) 8.07
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 59.6 (-0.1) 3.44
2013.01 127.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 38.0 58.4 (-0.3) 6.11
2013.03 111.3 57.9 57.5 (-0.9) 10.56
2013.04 124.8 72.4 57.9 (+0.4) 5.40
2013.05 131.4 78.7 (59.3 projected, +1.4) 9.73
2013.06 110.1 52.5 (59.7 projected, +0.4) 12.60
2013.07 115.5 57.0 (60.0 projected, +0.3) 9.47
2013.08 114.6 66.0 (60.3 projected, +0.3) 8.27
2013.09 102.6 36.9 (60.2 projected, -0.1) 5.23
2013.10  132.1 85.6 (58.7 projected, -1.5) 7.65
2013.10  145.6 (1) 3.2 (2A) / 95.0 (2B) / 80.2 (2C) (56.6 projected, -2.1) (4.4)

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 SIDC 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 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.