Solar Terrestrial Activity Report

Last major update issued on June 25, 2014 at 04:30 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update June 1, 2014)] [Cycle 24 progress (last update June 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update June 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update June 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update May 1, 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 June 24. Solar wind speed at SOHO ranged between 284 and 365 km/s.

Solar flux at 20h UTC on 2.8 GHz was 93.5 (decreasing 5.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 136.3. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.3). Three hour interval K indices: 33211121 (planetary), 33312321 (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: 80) and 5 active regions using 1K resolution (SN: 67) SDO images on the visible solar disk.

Region 12096 [N09E45] gained a few spots and was mostly quiet.
Region 12097 [N13E51] was quiet and stable.
New region 12098 [S07E18] emerged on June 23 and was numbered the next day by SWPC. Slow decay was observed late in the day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3559 [S09W39] decayed slowly and quietly.
New region S3572 [N04W63] emerged with a penumbra spot.

C2+ Flares (GOES):

Coronal mass ejections (CMEs)

June 22-24: 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 trans equatorial coronal hole (CH623) was in an Earth facing position on June 23-24.

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 quiet on June 25. Quiet to unsettled conditions are possible on June 26-27 due to effects from CH623.

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
12093	2014.06.15 2014.06.16				S09W46						plage location: S06W49
12094	2014.06.15 2014.06.16				S18W37						plage
S3558	2014.06.20				N15W36						plage
S3559	2014.06.21		2	2	S09W39	0007		AXX
12096	2014.06.21 2014.06.22	2	11	5	N09E42	0080	HAX	CAO			location: N09E45 area: 0160
S3564	2014.06.21				S19W53						plage
12097	2014.06.22	1	2	1	N12E49	0030	HAX	HSX			area: 0080
S3567	2014.06.22				S01W09						plage
S3568	2014.06.22				N13W29						plage
S3569	2014.06.22				N15W55						plage
12098	2014.06.23 2014.06.24	4	14	8	S09E18	0020	DRO	DRI			area: 0060 location: S07E18
S3572	2014.06.24		1	1	N04W63	0005		AXX
Total spot count:		7	30	17
Sunspot number:		37	80	67	(total spot count + 10 * number of spotted regions)
Weighted SN:		20	43	30	(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):		22	28	37	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.