|Charts (* = updated daily)||Data and archive|
|Solar wind (*)||Solar and geomagnetic data - last month (*)|
|Electron fluence (*)||Archived daily reports and monthly data since 2003.01 (September 9, 2017)|
|Solar cycle||Solar cycles 23-24 (September 1, 2017)||Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)|
|Cycle 24 progress (September 1, 2017) / Cycle 25 spots (new)||Noon SDO sunspot count 1K / 4K (*)|
|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, 2017)||3rd SSN Workshop, Tucson, 2013|
|Comparison of cycles 12, 13, 14, 16 and 24 (September 1, 2017)||4th SSN Workshop, Locarno, 2014|
|Solar polar fields vs. solar cycles (July 16, 2017)|
The geomagnetic field was quiet to unsettled on September 10. Solar wind speed at SOHO ranged between 452 and 603 km/s.
Solar flux at 23h UTC on 2.8 GHz was 92.7 (increasing 19.7 over the previous solar rotation. Earlier measurements on Sept.10 were flare enhanced and discarded). The average 90 day 10.7 flux at 1 AU was 83.1. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.0). Three hour interval K indices: 00000223 (planetary), 11111423 (Boulder)
The background x-ray flux is at the class C1 level.
At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 84) and in 5 active regions using 1K resolution (SN: 59) SDO images on the visible solar disk.
(Region 12673 produced a major X8 proton flare while transiting the
southwest limb. This produced a strong particle event which will likely continue
for some days. A very wide full halo CME was observed as well)
Region 12674 [N12W83] decayed slowly and quietly.
Region 12677 [N14W27] decayed slowly and quietly.
Region 12678 [N11W19] decayed slowly and quietly.
New region 12680 [N09E66] rotated into view on September 9 and was numbered by SWPC the next day.
Spotted regions not numbered (or interpreted differently)
New region S5795 [N37E02] emerged early in the day as a bipolar cycle 25 region. The trailing spot disappeared later in the day.
New region S5797 [N18W20] emerged with a tiny spot.
|Magnitude||Peak time (UT)||Location||AR||Recorded by||Comment|
|X8.2 (LDE)||16:06||S09W90||12673||GOES15||Full halo CME. Strong particle event|
September 8-10: No obviously Earth directed CMEs were observed in available LASCO imagery.
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 recurrent northern hemisphere coronal hole (CH824) will rotate across the central meridian on September 10-12.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is very poor due to a strong particle event. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to unsettled on September 11. The CME associated with the X8 event could arrive on September 12 and cause unsettled to major storm conditions. Quiet to active conditions are likely on September 13-15 due to effects from CH824.
|Coronal holes (1)||Coronal mass ejection (2)||M and X class flares (3)|
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.
(Click on image for 2K resolution). 4K 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
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlays
|Total spot count:||8||14||9|
|Sunspot number:||38||74||59||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||26||29||24||(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||41||47||k * (sunspot number)
As of May 7, 2016: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.80 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|
|2017.03||74.6||73.9||17.7||(25.0 projected, -1.6)||14.20|
|2017.04||80.3||80.8||32.6||(23.4 projected, -1.6)||11.70|
|2017.05||73.6||75.2||18.8||(22.3 projected, -1.1)||8.09|
|2017.06||74.7||77.1||19.4||(21.3 projected, -1.0)||6.08|
|2017.07||77.4||79.9||18.3||(20.2 projected, -1.1)||8.97|
|2017.08||77.9||79.8||33.1||(18.7 projected, -1.5)||10.66|
|2017.09||(114.1)||26.5 (2A) / 82.2 (2B) / 54.5 (2C)||(17.5 projected, -1.2)||(21.1)|
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.