Solar Terrestrial Activity Report

Last major update issued on March 24, 2014 at 04:50 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 March 16, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on March 23. Solar wind speed at SOHO ranged between 402 and 524 km/s, weakly under the influence of a high speed stream from CH608.

Solar flux at 20h UTC on 2.8 GHz was 157.0 (decreasing 13.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.5. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.5). Three hour interval K indices: 22212122 (planetary), 12222322 (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 14 active regions in 2K resolution (SN: 310) and 13 active regions in 1K resolution (SN: 219) SDO images on the visible solar disk.

Region 12005 [N12W73] was mostly unchanged and quiet.
Region 12008 [S10W32] decayed slowly and quietly.
Region 12010 [S13W13] developed slowly and produced several low level C flares. The region has two magnetic delta structures. An M class flare is possible.
Region 12012 [S16E05] lost the leader spot.
Region 12013 [N15E03] was quiet and stable.
Region 12014 [S12E21] developed and has polarity intermixing. A minor M class flare is possible. C5+ flare: C5.0 long duration event peaking at 03:48 UTC. This event was associated with an asymmetric full halo CME.
Region 12015 [S14W42] developed a magnetic delta structure. A minor M class flare is possible.
Region 12016 [S27W07] decayed early in the day, then began to develop again in leading polarity.
Region 12017 [N10E47] gained penumbral area and appears to be maturing. Several low level C flares were recorded.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3226 [S10W47] decayed slowly and quietly. SWPC has moved AR 12008 14 degrees to the west of where it should be to include the spots in ARs S3226 and S3258, the original AR 12008 still has spots.
S3244 [N16W09] reemerged with a penumbra spot.
S3248 [N01E31] was quiet and stable.
S3258 [S05W47] decayed slowly and quietly.
New region S3259 [S20E52] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

March 21: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
March 22: A partial halo CME was observed after the LDE in AR 12005, it is uncertain if this CME has Earth directed extensions.
March 23: An asymmetric full halo CME was observed after the C5 LDE in AR 12014. The CME could reach Earth on March 26.

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 small trans equatorial coronal hole (CH608) was in an Earth facing position on March 19-20.

Propagation

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

Forecast

The geomagnetic field is expected to be quiet on March 24-25 with some uncertainty on March 25 due to possible effects from the March 22 CME. Quiet to active conditions are possible on March 26 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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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
12005	2014.03.11 2014.03.12	1	2	1	N12W74	0160	HSX	CHO			area: 0260
12007	2014.03.13 2014.03.14				N11W61						trailing part of AR 12005
12008	2014.03.14 2014.03.15	6	3	1	S07W47	0030	CRO	BXO			area: 0012 SWPC has moved the region 14 degrees to the west and currently counts the spots of ARs S3226 and S3258. real location: S10W32
12015	2014.03.15 2014.03.22	4	4	2	S14W42	0090	CAO	DAC			beta-delta area: 0100
S3226	2014.03.15		8	4	S10W47	0022		CRO
S3227	2014.03.15				S26W53						plage
12010	2014.03.16 2014.03.17	26	55	27	S15W13	0180	DAC	DKC			beta-gamma-delta area: 0440 location: S13W13
S3231	2014.03.16				S19W52						plage
S3232	2014.03.16				S24W56						plage
S3233	2014.03.17				S27W22						plage
12012	2014.03.17 2014.03.18		5	3	S09W09	0016		AXX			location: S16E05
12013	2014.03.17 2014.03.18	2	17	11	N14E03	0020	CAO	CAO			area: 0060
12016	2014.03.17 2014.03.22	1	6	4	S28W07	0010	AXX	CRO			area: 0020
S3237	2014.03.17				S23W38						plage
12011	2014.03.18	4			S06W92	0110	CAO				rotated out of view
12014	2014.03.18 2014.03.19	16	45	23	S14E20	0170	DSC	DSC			location: S12E21 area: 0370
S3241	2014.03.18				N14W26						plage
S3242	2014.03.18				N21W57						plage
S3244	2014.03.19				N17W11						plage
S3245	2014.03.19				S18W48						plage
S3246	2014.03.19				S02W41						plage
S3248	2014.03.20		5	2	N01E31	0012		BXO
S3250	2014.03.20				N39W30						plage
12017	2014.03.21 2014.03.22	9	16	9	N09E45	0100	DAI	DAO			beta-gamma area: 0200
S3254	2014.03.21				S02W20						plage
S3255	2014.03.22				S12E43						plage
S3256	2014.03.22				S08E39						plage
S3258	2014.03.22		2		S05W47	0004		AXX
S3259	2014.03.23		1	1	S20E52	0006		AXX
Total spot count:		69	169	89
Sunspot number:		159	309	219	(total spot count + 10 * number of spotted regions)
Weighted SN:		107	215	135	(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):		95	108	120	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.