Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 5, 2013 at 04:10 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 November 3, 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 4. Solar wind speed at SOHO ranged between 307 and 488 km/s under the influence of weak effects from CH592.

Solar flux measured at 20h UTC on 2.8 GHz was 147.3 (increasing 35.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 119.5. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.9). Three hour interval K indices: 01221221 (planetary), 01121221 (Boulder).

The background x-ray flux is at the class B7 level.

At the time of counting spots (see image time) spots were observed in 7 active regions in 2K resolution (SN: 230) and 6 active regions in 1K resolution (SN: 132) SDO images on the visible solar disk.

Region 11882 [S10W73] was quiet and stable.
Region 11884 [S15W39] decayed further and was mostly quiet.
Region 11887 [N20W04] matured and was mostly quiet.
Region 11889 [S19W03] developed slowly and quietly.
Region 11890 [S12E52] is one of the largest regions observed during solar cycle 24 and has at least 2 magnetic delta structures. The most significant delta is in the eastern part of the largest trailing penumbra where it is difficult to observe a separation between oppposite polarity spots. The region is capable of producing X class flares.

Spotted regions not numbered by SWPC:
S2802 [S10W15] was quiet and stable.
S2803 [N04E48] lost the trailing spots while penumbra spots emerged in the leading polarity field.

An impressive full halo CME was observed from 05:09 UTC in STEREO-A and LASCO imagery, its source was a flare in a backsided northern hemisphere region (near the equator).

Coronal mass ejections (CMEs)

November 3-4: No obviously Earth directed CMEs were observed in LASCO or STEREO imagery.
November 2: A full halo CME was observed after 05h UTC, its source was backsided in a northern hemisphere active region (near the equator). Another impressive CME was observed later in the day after another backsided flare.

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) was in an Earth facing positon on October 31-November 3. A recurrent trans equatorial coronal hole (CH593) will likely rotate into an Earth facing position on November 7-8.

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 5-6 due to weak coronal hole effects and quiet on November 7. On November 10-11 effects from CH593 could cause some unsettled and active intervals.

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
11882 2013.10.23
2013.10.24
2 5 2 S10W74 0050 CAO HAX

 

11883 2013.10.26       N04W55        

plage

location: N04W42

11884 2013.10.26 10 20 10 S12W38 0110 DAC DSO

location: S15W39

area: 0230

11885 2013.10.26 2     S18W42 0160 HAX       part of AR 11884
11888 2013.10.27
2013.10.31
2     S13W82 0010 BXO     rotated out of view
11887 2013.10.29
2013.10.30
23 39 19 N21W05 0110 DSI DAI

area: 0200

S2791 2013.10.29       N13W57           plage
S2792 2013.10.30       S10E07           plage
S2796 2013.10.31       N05E19           plage
S2797 2013.10.31       S05W44           plage
S2798 2013.11.01       S22W40         plage
11890 2013.11.01
2013.11.02
31 63 27 S09E49 0830 EHC EKC beta-gamma-delta

area: 1400

location: S12E52

11889 2013.11.02 10 28 13 S18W05 0080 DAO DAI  

area: 0150

location: S19W03

S2800 2013.11.02       S08E34           plage
S2802 2013.11.02   3 1 S10W15 0008   BXO  
S2803 2013.11.03   2   N04E48 0004   AXX  
S2804 2013.11.03       N13W23         plage
S2805 2013.11.03       S25W29         plage
S2806 2013.11.03       S09W14         plage
Total spot count: 80 160 72  
Sunspot number: 150 230 132  (total spot count + 10 * number of spotted regions)
Weighted SN: 115 190 102  (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): 90 81 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
2013.11  144.5 (1) 17.0 (2A) / 127.8 (2B) / 83.5 (2C) (56.6 projected, -2.1) (4.3)

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.