Solar Terrestrial Activity Report

Last major update issued on January 6, 2014 at 05:05 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 December 16, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on January 5. Solar wind speed at SOHO ranged between 403 and 529 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 217.5 (increasing 49.4 over the last solar rotation and the highest recorded during cycle 24). The 90 day 10.7 flux at 1 AU was 144.4. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.6). Three hour interval K indices: 11211101 (planetary), 11201220 (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 13 active regions in 2K resolution (SN: 365) and 12 active regions in 1K resolution (SN: 240) SDO images on the visible solar disk.

Region 11937 [S14W68] was mostly quiet but could produce C flares.
Region 11938 [S14W58] decayed slowly and quietly.
Region 11942 [N10W04] developed slowly and was quiet.
Region 11943 [S12E07] was quiet and stable.
Region 11944 [S09E26] developed in the southeastern section with another large penumbral area forming. There are 2 significant magnetic delta structures in this penumbra. The region remains capable of producing major flares. C5+ flares: C6.6 at 15:18 UTC.
Region 11945 [N10W23] was quiet and stable.
Region 11946 [N09E23] developed and has weak polarity intermixing. C and minor M class flares are possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S2990 [S09W32] developed slowly and quietly.
New region S2991 [N06E80] rotated into view.
New region S2992 [N17E35] emerged with 2 spots.
New region S2993 [N04E08] emerged with a penumbra spot.
New region S2994 [N11W54] emerged quickly with several spots.
New region S2995 [S15E46] emerged with penumbra spots.

Coronal mass ejections (CMEs)

January 3, 5: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 4: A full halo CME was observed late in the day after the M4 event in AR 11943. This CME could reach Earth on January 7.

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 (CH599) will likely rotate into an Earth facing position on January 9-10.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet on January 6. On January 7 the CME observed late on January 4 could reach Earth and cause unsettled to major storm conditions. Quiet to active is likely on January 8.

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
11937	2013.12.25 2013.12.26	21	17	10	S13W71	0160	DAC	DAC			beta-gamma area: 0330 location: S14W68
11938	2013.12.26 2013.12.27	3	2	1	S14W59	0010	CRO	CRO			area: 0018
S2959	2013.12.27				N18W51						plage
S2965	2013.12.29				S28W49						plage
S2966	2013.12.29				S14W32						plage
S2971	2013.12.30				S20W20						plage
11943	2013.12.30 2013.12.31	7	23	7	S11E07	0030	CRO	CRO			area: 0055 location: S12E19
11942	2013.12.30 2013.12.31	3	16	8	N10W06	0020	HSX	DAO			area: 0070
11944	2013.12.31 2014.01.01	112	125	67	S09E25	1480	FKC	FKC			beta-gamma-delta area: 2700
S2977	2013.12.31				N14W42						plage
11945	2014.01.01 2014.01.02	1	9	3	N11W25	0010	AXX	BXO			location: N10W23
S2980	2014.01.01				S04W32						plage
S2983	2014.01.03				N21E39						plage
S2984	2014.01.03				N38W31						plage
S2986	2014.01.03				S26W07						plage
11946	2014.01.04	8	25	13	N09E21	0080	DAI	DAC			beta-gamma location: N09E23 area: 0300
S2988	2014.01.04				N20E08						plage
S2989	2014.01.04				N00W28						plage
S2990	2014.01.04		3	3	S09W32	0014		BXO
S2991	2014.01.05		1	1	N06E80	0160		HSX
S2992	2014.01.05		2	2	N17E35	0020		BXO
S2993	2014.01.05		1	1	N04E08	0004		AXX
S2994	2014.01.05		8	4	N11W54	0070		DRO
S2995	2014.01.05		3		S15E46	0006		BXO
Total spot count:		155	235	120
Sunspot number:		225	365	240	(total spot count + 10 * number of spotted regions)
Weighted SN:		186	274	159	(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):		135	128	132	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.