Solar Terrestrial Activity Report

Last major update issued on November 8, 2011 at 05:35 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update November 1, 2011)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 1, 2011)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 1, 2011)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 2, 2011)]

[POES auroral activity level since October 2009 - updated November 4, 2011]
Annotated geomagnetic activity charts - Carrington rotation 2114 [August-September 2011] - 2115 [September-October 2011]
[Solar polar fields vs solar cycles - updated June 27, 2011]

Recent activity

The geomagnetic field was quiet to unsettled on November 7. Solar wind speed ranged between 315 and 388 km/s. Solar wind speed increased slowly as a low speed stream from CH484 gradually became the dominant solar wind factor.

Solar flux measured at 20h UTC on 2.8 GHz was 182.1 (increasing 52.0 over the last solar rotation, and a new high (not counting flare enhanced measurements) for cycle 24). The planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.4). Three hour interval K indices: 03001121 (planetary), 03212321 (Boulder).

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

At midnight UTC the visible solar disk had 10 spotted regions (in 2K resolution SDO images).

Region 11334 [N13W87] was quiet and stable
Region 11336 [N17W33] was quiet and stable.
Region 11338 [S14W12] became less complex and was quiet.
Region 11339 [N19E05] decayed losing quite a bit of penumbral area. There is still a chance of a major flare. Flares: C3.5 at 03:10, C1.4 at 09:34, C3.2 at 23:28 UTC.
Region 11340 [S09E37] was quiet and stable.
Region 11341 [N10E56] was quiet and stable.
Region 11342 [N17E47] developed many new spots. C class flaring is possible.
Region 11343 [N27E77] was quiet and stable.
New region 11344 [S23E06] emerged in the southeast quadrant with spots on November 3, became spotless and reemerged with several spots on November 6. SWPC numbered the region on Nov.7 when slow decay was observed.

Spotted regions not reported by NOAA/SWPC:
[S1314] emerged in the northeast quadrant on November 7. Location at midnight: N20E23

A large filament eruption in the northwest quadrant was observed beginning at 22:32 UTC in SDO images. A CME was observed both in STEREO and LASCO images, but does not appear to be Earth directed.

Coronal mass ejections (CMEs)

November 5-7: No obviously Earth directed CMEs observed.

Coronal holes

Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

A small coronal hole (CH484) in the northern hemisphere was in an Earth facing position on November 3.

The above coronal hole map is based on a new method where coronal holes are detected automatically. The method may need some fine tuning, however, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using the new method, the extent and intensity of both holes are consistent with other data sources.

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 8 due to weak effects from CH484 and quiet on November 9-10.

Coronal holes (1) Coronal mass ejections (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 higher resolution image) Compare to the previous day's image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue (blue-green) 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 polarity overlay
Comment
SWPC STAR SDO SWPC STAR Current Previous
11336 2011.10.29
2011.10.31
  6 N11W43 0000   BXO location: N17W33
11334 2011.10.29
2011.10.30
2 1 N12W87 0040 CSO HSX  
11337 2011.10.30
2011.10.31
    N18W28         location: N25W23

plage

11338 2011.10.31
2011.11.01
16 24 S12W11 0240 ESI DSI

area: 0400

location: S14W12

11339 2011.11.01 45 76 N19E05 1240 FKC FKC beta-gamma-delta
11344 2011.11.03
2011.11.07
1 5 S22E06 0000 AXX BXO  
S1309 2011.11.03     S22W40           plage
11340 2011.11.04
2011.11.05
1 1 S09E36 0090 HSX HSX area: 0150
S1311 2011.11.04     N16W14           plage
11341 2011.11.05 3 9 N10E55 0180 CAO CAO area: 0240
11342 2011.11.05 5 28 N17E47 0170 EAO EHI area: 0300
11343 2011.11.05
2011.11.06
1 1 N27E62 0140 HSX HSX location: N27E64
S1313 2011.11.05     N25W54           plage
S1314 2011.11.07   1 N20E23 0000   AXX  

 

Total spot count: 74 152  
Sunspot number: 154 252  (total spot count + 10 * number of spotted regions)
Classification adjusted SN: 114 197  (Sum of total spot count + classification adjustment for each AR. Classification adjustment: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 92 113  k * (sunspot number). k = 0.6 for SWPC. k = 0.45 (changed from 0.33 on Nov.1) for STAR SDO

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2008.07 65.7 (SF minimum) 0.5 2.8 (-0.4)  
2008.12 69.2 0.8 1.7 (-)
sunspot minimum
3.25
2010.07 79.8 16.1 16.7 (+0.3) 6.31 / 5.15
2010.08 79.2 19.6 17.4 (+0.7) 8.49 / 7.77
2010.09 81.1 25.2 19.6 (+2.2) 5.33 / 5.45
2010.10 81.6 23.5 23.2 (+3.6) 6.07 / 6.27
2010.11 82.5 21.5 26.5 (+3.3) 4.80 / 5.50
2010.12 84.2 14.4 28.8 (+2.3) 3.41 / 4.35
2011.01 83.6 19.1 31.0 (+2.2) 4.32 / 5.51
2011.02 94.6 29.4 33.4 (+2.4) 5.41 / 6.44
2011.03 115.0 56.2 36.9 (+3.5) 7.79 / 8.18
2011.04 112.6 54.4 41.8 (+4.9) 9.71 / 8.83
2011.05 95.8 41.6 (47.4 predicted, +5.6) 9.18 / 8.94
2011.06 95.8 37.0 (52.5 predicted, +5.1) 8.96 / 8.06
2011.07 94.2 43.9 (58.2 predicted, +5.7) 9.14 / 8.16
2011.08 101.7 50.6 (63.7 predicted, +5.5) 8.16 / 7.26
2011.09 133.8 78.0 (67.0 predicted, +3.3) 12.80 / 12.27
2011.10 137.3 88.0 (70.5 predicted, +3.5) 7.52
2011.11  165.3 (1) 30.0 (2A) / 128.4 (2B) (74.9 predicted, +4.4) (7.23)

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) Month average to date.
3) Running average based on the preliminary daily SWPC ap indices. Values in red are based on the official NGDC ap indices.

This report has been prepared by Jan Alvestad. It is based on 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.