Solar Terrestrial Activity Report

Last major update issued on July 15, 2014 at 05:25 UTC.

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

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated June 4, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on July 14. Solar wind speed at SOHO ranged between 288 and 384 km/s. A weak solar wind shock was observed at 13:27 at SOHO. The source of the disturbance may have been the partial halo CME observed on July 10 from a location near the southwest limb.

Solar flux at 20h UTC on 2.8 GHz was 109.4 (decreasing 4.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 139.5. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.5). Three hour interval K indices: 10113322 (planetary), 21223323 (Boulder).

The background x-ray flux is at the class B2 level.

At the time of counting spots (see image time), spots were observed in 5 active regions using 2K resolution (SN: 95) and 4 active regions using 1K resolution (SN: 63) SDO images on the visible solar disk.

Region 12109 [S08W86] rotated quietly to the southwest limb.
Region 12113 [N07W30] decayed slowly and quietly.
Region 12114 [S20W11] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3640 [S19E14] emerged with penumbra spots.
New region S3641 [S13W60] emerged with a penumbra spot.

C2+ Flares (GOES):

Coronal mass ejections (CMEs)

July 12-14: 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

No signficant 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 poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on July 15-17.

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
12109	2014.07.01 2014.07.02	1	1	1	S08W86	0300	HHX	HHX			area: 0650
12111	2014.07.03 2014.07.04	1			N06W71	0010	AXX				spotless
S3614	2014.07.04				N06W57						plage
12113	2014.07.06	11	20	11	N07W32	0040	DAO	CRI			merged with AR 12117 location: N07W30
12114	2014.07.07 2014.07.08	5	19	9	S20W14	0050	BXO	CRO
12116	2014.07.08 2014.07.10				S28W10						plage
S3631	2014.07.08				S15W16						plage
S3632	2014.07.08				S16W50						plage
S3633	2014.07.08				N15W46						plage
12117	2014.07.11	2			N09W23	0010	AXX				merged with AR 12113
S3638	2014.07.13				N19W16						plage
S3639	2014.07.13				S31W25						plage
S3640	2014.07.14		4	2	S19E14	0011		AXX
S3641	2014.07.14		1		S13W60	0002		AXX
Total spot count:		20	45	23
Sunspot number:		70	95	63	(total spot count + 10 * number of spotted regions)
Weighted SN:		35	61	38	(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):		42	33	35	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.