Solar Terrestrial Activity Report

Last major update issued on November 12, 2012 at 05:30 UTC.

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[Solar cycles 23-24 (last update November 1, 2012)] [Cycle 24 progress (last update November 1, 2012) ]
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[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 1, 2012)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 1, 2012)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 4, 2012)]

[POES auroral activity level since October 2009 - updated October 7, 2012]
[Solar polar fields vs solar cycles - updated June 27, 2011]

Recent activity

The geomagnetic field was very quiet on November 11. Solar wind speed at SOHO ranged between 270 and 342 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 133.3 (decreasing 3.5 over the last solar rotation). The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.5). Three hour interval K indices: 11001100 (planetary), 11012211 (Boulder).

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

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

Region 11609 [S16E05] was quiet and stable.
Region 11610 [S23E06] developed slowly and was mostly quiet.
Region 11611 [N12E27] was quiet and stable.
Region 11612 [N07E37] was quiet and stable.
New region 11613 [S23E59] rotated into view on November 9 and got its NOAA number 2 days later.
New region 11614 [N14E72] rotated into view on November 10 and was numbered by SWPC the next day.
New region 11615 [N09E62] emerged near the northeast limb.

Spotted regions not numbered by NOAA/SWPC:
S2040 [N14W08] was quiet and stable.
New region S2045 [S15E20] emerged with several tiny spots.
New region S2046 [N15W63] emerged with several spots.

Coronal mass ejections (CMEs)

November 9: A partial halo CME was observed after a filament eruption in the southern hemisphere, the CME could reach Earth late on November 12 or on November 13.
November 10: A small CME, possibly with a weak Earth directed component, was observed following a filament eruption near AR 11608 starting at approx. 05h UTC.
November 11: No obviously Earth directed CMEs were observed in LASCO and 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 trans equatorial coronal hole (CH545) was in an Earth facing position on November 10.

The above coronal hole map is based on a method where coronal holes are detected automatically. While the method may need some fine tuning, 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 this method, the extent and intensity of both CHs 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 good. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on November 12. From late on Nov.12 and on Nov.13 there is a chance the CME observed on Nov.9 will arrive and cause unsettled to minor storm conditions. The CME could arrive just before a high speed stream from CH545. The CME observed on Nov.10 could arrive on Nov.13 but may not be noticable as it was small and there will likely be more significant disturbances in progress.

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. 0.5k 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 magnetic polarity overlay		Comment
		SWPC	STAR SDO				SWPC	STAR	Current	Previous
			2K	1K
11605	2012.11.01 2012.11.04				N18W74						plage
11604	2012.11.02 2012.11.03				N07W69						plage
11606	2012.11.04				S15W52						plage
11608	2012.11.04 2012.11.05				S20W17						plage
S2033	2012.11.05				S18W34						plage
11609	2012.11.05 2012.11.06	1	11	1	S15E01	0010	HRX	BXO
11610	2012.11.06 2012.11.07	18	47	20	S25E02	0150	DAI	DAI			beta-gamma area: 0270
S2038	2012.11.07				S06W09						plage
11611	2012.11.07 2012.11.08	9	17	6	N12E27	0210	DSO	ESO			area: 0380
S2040	2012.11.07		4	2	N14W08	0000		AXX
11612	2012.11.08	1	2	1	N05E36	0060	HSX	HSX			area: 0140 location: N07E37
S2041	2012.11.08				N04W12						plage
11613	2012.11.09 2012.11.11	1	4	2	S21E57	0070	HSX	CSO			area: 0160 location: S23E59
11614	2012.11.10 2012.11.11	3	14	6	N15E72	0110	DSO	DSO
S2044	2012.11.10				S09W56						plage
11615	2012.11.11	3	6	2	N09E61	0010	BXO	CRO
S2045	2012.11.11		2	1	S15E20	0000		BXO
S2046	2012.11.11		5	2	N15W63	0010		BXO
Total spot count:		36	112	43
Sunspot number:		106	212	143	(total spot count + 10 * number of spotted regions)
Weighted SN:		64	140	71	(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):		64	74	79	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

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 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.