Solar Terrestrial Activity Report

Last major update issued on March 9, 2014 at 07:45 UTC.

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

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated February 23, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was very quiet on March 8. Solar wind speed at SOHO ranged between 335 and 406 km/s.

Solar flux at 20h UTC on 2.8 GHz was 141.6 (decreasing 27.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.5. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.6). Three hour interval K indices: 10110001 (planetary), 10122211 (Boulder).

The background x-ray flux is at the class B8 level.

At the time of counting spots (see image time) spots were observed in 12 active regions in 2K resolution (SN: 247) and 10 active regions in 1K resolution (SN: 173) SDO images on the visible solar disk.

Region 11990 [S12W80] decayed slowly and quietly as it rotated to the southwest limb.
Region 11991 [S26W57] was mostly quiet and decayed quickly with only small trailing polarity spots remaining.
Region 11996 [N14W23] has polarity intermixing and could produce occasional C class flares.
Region 11998 [S10E28] was quiet and stable.
Region 11999 [S16W18] decayed and could soon become spotless.
Region 12000 [S11E14] decayed slowly and quietly.
Region 12001 [N19W65] gained spots and was quiet.
New region 12002 [S18E65] rotated into view on March 7 and was numbered by SWPC the next day. The region developed but has only small spots. C5+ flare: M1.4 at 23:47 UTC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3197 [N09W07] was quiet and stable.
New region S3202 [N26W07] emerged and has umbra on one spot.
New region S3203 [N01W22] emerged with a penumbra spot.
New region S3204 [S01E43] emerged with a penumbra spot and has the polarity layout of a northern hemisphere group.

Coronal mass ejections (CMEs)

March 6-8: 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 northern hemisphere coronal hole (CH606) may have been in an Earth facing position on March 5-6, the coronal hole could be too far to the north to become geoeffective. A small southern hemisphere coronal hole (CH607) will likely rotate into an Earth facing position on March 9.

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 March 9-11. On March 12-13 there is a chance of a few unsettled intervals due to effects from CH607.

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	Magnetic (SDO)				SWPC	STAR	Current	Previous
			2K	1K
11990	2014.02.24	2	2	1	S12W82	0110	HSX	HSX			area: 0170 location: S12W80
11991	2014.02.25 2014.02.26	5	5	3	S26W61	0040	CAO	HRX			location: S26W57 area: 0025
11993	2014.02.25 2014.02.26				N17W75						plage
11995	2014.02.28	2			S16W89	0030	CAO				rotated out of view
S3173	2014.02.28				N15W58						plage
11996	2014.03.01 2014.03.02	16	39	21	N15W23	0080	DAI	DRI			beta-gamma location: N14W23 area: 0120
S3176	2014.03.02				N09W07						plage
S3177	2014.03.02				N21W55						plage
S3182	2014.03.02				S12W37						plage
S3185	2014.03.03				N14W50						plage
S3186	2014.03.03				N08W38						plage
11999	2014.03.04 2014.03.05	2	3	2	S16W19	0010	BXO	BXO
11998	2014.03.04 2014.03.05	5	27	17	S09E27	0080	CAO	CAO			location: S10E28 area: 0150
S3190	2014.03.04				S06W14						plage
S3191	2014.03.04				S24W30						plage
12000	2014.03.05 2014.03.06	7	13	8	S11E13	0040	CAO	CRI			area: 0070
S3194	2014.03.05				N16E01						plage
12001	2014.03.05 2014.03.06	4	14	8	N19W65	0050	CAO	CRI			beta-gamma
S3196	2014.03.07				N10E05						plage
S3197	2014.03.07		4	2	N09W07	0018		AXX
S3198	2014.03.07				S20W27						plage
S3199	2014.03.07				S27E05						plage
12002	2014.03.07 2014.03.08	5	16	9	S19E64	0050	CAO	DRI			beta-gamma area: 0090
S3202	2014.03.08		2	2	N26W07	0010		CRO
S3203	2014.03.08		1		N01W22	0002		AXX
S3204	2014.03.08		1		S01E43	0003		AXX
Total spot count:		48	127	73
Sunspot number:		138	247	173	(total spot count + 10 * number of spotted regions)
Weighted SN:		88	155	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):		83	86	95	k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

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 WDC-SILSO 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 GFZ 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.