Solar Terrestrial Activity Report

Last major update issued on November 11, 2011 at 05:40 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 7, 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 on November 10. Solar wind speed ranged between 334 and 402 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 178.6 (increasing 42.5 over the last solar rotation). The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.9). Three hour interval K indices: 00001211 (planetary), 10012222 (Boulder).

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

At midnight UTC the visible solar disk had 11 spotted regions (in 2K resolution SDO images).

Region 11338 [S13W51] decayed slowly and quietly.
Region 11339 [N20W35] lost penumbral area and still has many spots. There's two minor magnetic delta structures in the largest penumbra. Flare: C6.0/1F long duration event peaking at 18:31 UTC.
Region 11340 [S08W03] was quiet and stable.
Region 11341 [N10E15] developed slowly and has polarity intermixing. C flares are possible.
Region 11342 [N17E06] was quiet and stable.
Region 11343 [N28E26] was quiet and stable.
Region 11344 [S22W33] was quiet and stable.
Region 11345 [S25W15] developed further and has polarity intermixing. C flares are possible.

Spotted regions not reported by NOAA/SWPC:
[S1315] emerged in the southeast quadrant on November 8. Location at midnight: S20E15
[S1317] emerged in the southern hemisphere near the central meridian on November 8 and developed slowly on Nov.9-10. SWPC apparantly considers this to be part of region 11344. Location at midnight: S17W31

Coronal mass ejections (CMEs)

November 8, 10: No obviously Earth directed CMEs observed.
November 9: A full halo CME was observed after a filament eruption in the northeast quadrant near region 11342.

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

No obvious coronal holes are near Earth facing positions.

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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on November 11. The CME observed on Nov.9 could arrive late on Nov.11 or most likely on Nov.12 and cause unsettled to minor storm conditions. On Nov.13 quiet to unsettled conditions are likely.

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
    N14W83           plage
11337 2011.10.30
2011.10.31
    N17W71           plage
11338 2011.10.31
2011.11.01
4 11 S13W51 0190 CSO CSO

 

11339 2011.11.01 45 69 N19W33 1020 FKC EKC beta-gamma-delta
11344 2011.11.03
2011.11.07
7 4 S19W31 0060 CRO BXO area: 0000

SWPC is including S1317 in this region

11340 2011.11.04
2011.11.05
1 2 S09W04 0080 HSX CSO area: 0140
S1311 2011.11.04     N16W53           plage
11341 2011.11.05 3 17 N08E14 0110 CSO DAI beta-gamma

location: N10E15

area: 0220

11342 2011.11.05 5 13 N15E15 0180 CSO CHO location: N17E06
11343 2011.11.05
2011.11.06
1 4 N27E23 0180 HSX HSX location: N28E26
S1314 2011.11.07     N20W16           plage
S1315 2011.11.08   3 S20E15 0000   BXO  
S1316 2011.11.08     N03W18           plage
S1317 2011.11.08   17 S17W31 0130   DSI  
11345 2011.11.09 6 16 S25W16 0090 DRO DAI beta-gamma

area: 0120

S1318 2011.11.10   1 N15E37 0000   AXX  

 

Total spot count: 72 157  
Sunspot number: 152 267  (total spot count + 10 * number of spotted regions)
Classification adjusted SN: 113 207  (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): 91 120  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  169.7 (1) 47.2 (2A) / 141.7 (2B) (74.9 predicted, +4.4) (6.13)

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.