Solar Terrestrial Activity Report

Last major update issued on March 8, 2014 at 08:10 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 7. Solar wind speed at SOHO ranged between 348 and 461 km/s.

Solar flux at 20h UTC on 2.8 GHz was 148.2 (decreasing 23.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.7. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.9). Three hour interval K indices: 00001110 (planetary), 10102212 (Boulder).

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

At the time of counting spots (see image time) spots were observed in 14 active regions in 2K resolution (SN: 260) and 11 active regions in 1K resolution (SN: 181) SDO images on the visible solar disk.

Region 11990 [S12W67] was quiet and stable. A small negative polarity umbra is very close to merging with the single large penumbra. If this occurs the region would again have a magnetic delta structure.
Region 11991 [S26W46] displayed severe fragmentation of what was the single remaining large penumbra.
Region 11993 [N17W60] decayed further and could soon become spotless.
Region 11995 [S17W77] decayed slowly and quietly.
Region 11996 [N14W10] decayed slowly and quietly.
Region 11998 [S10E41] was quiet and stable.
Region 11999 [S16W05] decayed quietly.
Region 12000 [S11E28] gained some spots but lost umbra on one polarity.
Region 12001 [N19W50] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3196 [N10E18] emerged with penumbra spots.
New region S3197 [N09E07] emerged with penumbra spots.
New region S3198 [S20W14] emerged with a penumbra spot.
New region S3199 [S27E18] emerged with a penumbra spot.
New region S3200 [S19E78] rotated into view. The region was the source of the most energetic event of the day, a C3.5 flare which started right before midnight and peaked at 00:07 UTC on March 8.

Coronal mass ejections (CMEs)

March 5-7: 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 may 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 with a chance of unsettled intervals on March 8-9 due to possible effects from CH606. Quiet conditions are likely on March 10-11 with weak coronal hole effects possible on March 12-13.

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	9	8	4	S13W68	0200	CSO	DSO			beta-gamma area: 0210 location: S12W67
11991	2014.02.25 2014.02.26	7	11	7	S24W51	0090	EAO	CAO			location: S26W46 area: 0070
11993	2014.02.25 2014.02.26	1	1		N17W61	0010	AXX	AXX
11995	2014.02.28	2	3	2	S16W76	0040	DAO	DRO
S3173	2014.02.28				N15W45						plage
11996	2014.03.01 2014.03.02	21	34	22	N15W10	0110	DAI	DRI			location: N14W10
S3176	2014.03.02				N09E06						plage
S3177	2014.03.02				N21W42						plage
S3181	2014.03.02				S15W52						plage
S3182	2014.03.02				S12W24						plage
S3185	2014.03.03				N14W37						plage
S3186	2014.03.03				N08W25						plage
11999	2014.03.04 2014.03.05	12	14	9	S16W06	0060	DSO	BXO			area: 0040
11998	2014.03.04 2014.03.05	6	12	7	S08E39	0100	CAO	CAO			location: S10E41 area: 0140
S3190	2014.03.04				S06W01						plage
S3191	2014.03.04				S24W17						plage
12000	2014.03.05 2014.03.06	8	20	12	S11E27	0070	CSO	CRI			area: 0120
S3194	2014.03.05				N16E14						plage
12001	2014.03.05 2014.03.06	5	8	4	N18W51	0060	BXO	DRO
S3196	2014.03.07		2		N10E18	0006		AXX
S3197	2014.03.07		2	1	N09E07	0006		AXX
S3198	2014.03.07		1	1	S20W14	0004		AXX
S3199	2014.03.07		1		S27E18	0002		AXX
S3200	2014.03.07		3	2	S19E78	0030		CRO
Total spot count:		71	120	71
Sunspot number:		161	260	181	(total spot count + 10 * number of spotted regions)
Weighted SN:		106	150	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):		97	91	100	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.