Solar Terrestrial Activity Report

Last major update issued on January 31, 2014 at 04:35 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update January 1, 2014)] [Cycle 24 progress (last update January 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 1, 2014)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated January 11, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on January 30. Solar wind speed at SOHO ranged between 326 and 374 km/s.

Solar flux at 20h UTC on 2.8 GHz was 160.5 (decreasing 21.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 146.8. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.1). Three hour interval K indices: 22100000 (planetary), 22101311 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time) spots were observed in 12 active regions in 2K resolution (SN: 256) and 11 active regions in 1K resolution (SN: 183) SDO images on the visible solar disk.

Region 11959 [S23W87] was quiet and stable.
Region 11960 [S15W83] was quiet and stable.
Region 11963 [S04W58] decayed slowly and quietly.
Region 11967 [S12E46] has multiple magnetic delta structures within the largest spot complex. An X class flare is possible. C5+ flares: M2.1 at 06:39, M1.1 at 08:11 (associated with a simultaneous filament eruption and a halo CME), major M6.6/2N at 16:11 UTC. The latter event was associated with an extensive full halo CME.
Region 11968 [N10E42] developed slowly and could produce C and minor M class flares.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3064 [N23W24] reemerged with a penumbra spot.
S3071 [S10W04] was quiet and stable.
S3072 [S15W56] decayed slowly and quietly.
S3073 [N20E47] reemerged with penumbra spots.
S3075 [S12E69] was quiet and stable.
S3076 [N13W11] was quiet and stable.
New region S3078 [S23E17] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

January 28: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 29: A halo CME was observed after a filament eruption in the southwest quadrant. While the core of the CME will not reach Earth, there's a chance a weak solar wind shock will be observed on February 1.
January 30: A halo CME was observed after an M1 event in AR 11967 at 08:11 UTC. The CME was faint over the west limbs and the north pole. A much larger CME was observed after the M6 flare in AR 11967 at 16:11 UTC. This CME could reach Earth on February 2.

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

No obvious coronal holes are currently in or near Earth facing positions.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet on January 31. On February 1 there's a chance of a few unsettled intervals due to weak CME effects. On February 2 quiet to minor storm conditions are possible due to CME effects.

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
11959	2014.01.17 2014.01.18	1	1	1	S23W88	0060	HAX	HAX			area: 0150
11960	2014.01.17 2014.01.18	2	1	1	S15W82	0050	HSX	HSX			area: 0140
11963	2014.01.19 2014.01.21		1		S18W68	0002		AXX			SWPC location on Jan.27: S06W25 location: S04W56
11964	2014.01.20 2014.01.21				S09W63						SWPC location on Jan.27: S14W28 location: S19W61 plage
11965	2014.01.20 2014.01.22	5			S15W56	0010	BXO				SWPC location on Jan.28: S14W24 location: S14W40 spotless
S3055	2014.01.21				N15W46						plage
S3057	2014.01.22				N05W29						plage
S3060	2014.01.24				S01W46						plage
S3061	2014.01.24				N08W53						plage
S3062	2014.01.24				S28W53						plage
11966	2014.01.25				S12W43						merged with AR 11965
S3064	2014.01.26		1	1	N23W24	0005		AXX
11967	2014.01.26 2014.01.27	42	80	45	S14E41	1190	FKC	FKC			beta-gamma-delta area: 1870 location: S12E46
11968	2014.01.27	12	39	17	N09E41	0160	EAO	EAI			location: N10E42 area: 0290
S3070	2014.01.28				N13E02						plage
S3071	2014.01.28		4	3	S10W04	0015		BXO
S3072	2014.01.28		2	1	S15W56	0007		BXO			SWPC has moved AR 11965 to this location
S3073	2014.01.28		2	1	N20E47	0010		AXX
S3074	2014.01.29				S17W20						plage
S3075	2014.01.29		2	1	S12E69	0012		HRX
S3076	2014.01.29		2	1	N13W11	0015		BXO
S3078	2014.01.30		1	1	S23E17	0005		AXX
Total spot count:		62	136	73
Sunspot number:		112	256	183	(total spot count + 10 * number of spotted regions)
Weighted SN:		87	164	101	(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):		67	91	101	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 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.