|Charts (* = updated daily)||Data and archive|
|Solar wind (*)||Solar and geomagnetic data - last month (*)|
|Electron fluence (*)||Archived daily reports and monthly data from 2003.01 (September 1, 2015)|
|Solar cycle||Solar cycles 23-24 (September 1, 2015)||Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)|
|Cycle 24 progress (September 1, 2015)||Noon SDO sunspot count 1K Reference: 4K (large file) (*)|
|Solar cycles 1-24 (July 17, 2015)||POES auroral activity level October 2009 - December 2012|
|Comparison of cycles 21, 22, 23 and 24 (September 1, 2015)||3rd SSN Workshop, Tucson, 2013|
|Comparison of cycles 12, 13, 14, 16 and 24 (September 1, 2015)||4th SSN Workshop, Locarno, 2014|
|Solar polar fields vs solar cycles (August 18, 2015)|
The geomagnetic field was quiet to major storm on September 8 under the continued influence of CME effects. Solar wind speed at SOHO ranged between 461 and 526 km/s. The Bz component of the interplanetary magnetic field swung northwards early in the day causing a sharp decline in geomagnetic activity. On September 9 Bz swung southwards again causing active to minor storm conditions.
Solar flux at 20h UTC on 2.8 GHz was 83.5 (decreasing 15.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 111.1. The Potsdam WDC planetary A index was 23 (STAR Ap - based on the mean of three hour interval ap indices: 23.3). Three hour interval K indices: 65312213 (planetary), 553130** (Boulder).
The background x-ray flux is at the class A8 level.
At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 91) and 4 active regions using 1K resolution (SN: 55) SDO images on the visible solar disk.
Region 12409 [N05W34] developed slowly and was
Region 12411 [N14E12] was quiet and stable.
Region 12412 [S07E32] gained spots and was quiet.
Spotted regions not numbered (or interpreted differently) by SWPC:
S4744 [N08E57] was quiet and stable.
S4746 [N23E03] developed slowly and quietly.
New region S4747 [S10E21] emerged with a penumbra spot.
|Magnitude||Peak time (UTC)||Location||AR||Recorded by||Comment|
September 6-8: No obviously Earth directed CMEs were observed.
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 (CH688) was in an Earth facing position on September 7-8. A northern hemisphere coronal hole (CH689) will likely rotate into a potentially geoeffective position on September 11-12.
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 fair.
The geomagnetic field is expected to be quiet to minor storm on September 9 due to lingering CME effects. Quiet to unsettled conditions are possible on September 10-11 due to effects from CH688.
|Coronal holes (1)||Coronal mass ejection (2)||M and X class flares (3)|
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.
(Click on image for 2K resolution) Compare to the previous day's image.
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.
|Active region||Date numbered
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlays
|Total spot count:||10||31||15|
|Sunspot number:||40||91||55||(total spot count + 10 * number of spotted regions)|
|Relative sunspot number (Wolf number):||44||45||47||k * (sunspot number)
As of July 1, 2015: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.85 for MSN 1K (MSN=Magnetic Sunspot Number)
|Month||Average solar flux||International sunspot number
|Smoothed sunspot number (4)||Average
|166.3||146.1 (cycle peak)||110.5 (+1.2)||10.70|
|2014.04||143.9||144.8||112.5||116.4 (+2.1) (solar max)||7.88|
|2015.03||125.9||124.6||54.5||(82.1 projected, -4.5)||16.14|
|2015.04||128.8||129.7||78.0||(78.0 projected, -4.1)||10.73|
|2015.05||120.0||122.6||90.0||(75.3 projected, -2.7)||8.29|
|2015.06||122.3||126.1||68.3||(71.6 projected, -3.7)||13.15|
|2015.07||107.0||110.8||66.4||(67.9 projected, -3.7)||8.83|
|2015.08||105.4||108.0||64.6||(66.7 projected, -1.2)||13.8|
|2015.09||(86.5)||10.1 (2A) / 37.8 (2B) / 62.3 (2C)||(67.0 projected, +0.3)||(15.9)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
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.
4) Updated to new data set from WDC-SILSO on July 1, 2015
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 Universal Time. Comments and suggestions are always welcome.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.