[ADXA] THE LOPSIDED SOLAR CYCLE

Tue Dec 8 11:03:15 EST 2020

Interesting info on sunspots, particularly the chart – 1958-1961 was an amazing time to work DX.  DXCC was attainable with a gob of spit and a wet noodle 😊

73

Bill Priakos – W5SJ

THE LOPSIDED SOLAR CYCLE: Solar physicists have long known that the two hemispheres of the sun don't always operate in sync.  While one hemisphere is active, the other may be utterly quiet; Solar Max in the North can be offset from Solar Max in the South by as much as two years. The sun's lopsided behavior is on display right now, as shown in this Dec. 4th photo from NASA's Solar Dynamics Observatory:

[https://spaceweather.com/images2020/05dec20/red_strip.png]<https://spaceweather.com/images2020/05dec20/red.jpg>

In the southern hemisphere, there are 4 times more active regions than in the north. Since the big sunspots of Solar Cycle 25 started appearing in October 2020, approximately 82% of all 'spots have been in the south. The vast majority of all solar activity is coming from just one half of the sun.

An excellent historical review of sunspot activity<https://link.springer.com/article/10.1007/lrsp-2015-4> penned by retired NASA scientist David Hathaway shows that solar cycles often tilt one way or the other. The great Solar Cycle 19 of the 1960s, for instance, was mostly southern, an asymmetry which spilled over into Solar Cycle 20 as well:

[https://spaceweather.com/images2020/05dec20/northVsouth_strip.png]<https://link.springer.com/article/10.1007/lrsp-2015-4#Fig35>
Smoothed monthly sunspot areas for northern and southern hemispheres separately. The difference between the curves is filled in red if north dominates or blue if south dominates.

Other solar cycles have been more balanced, with only razor-thin margins separating one hemisphere from the other.

How will Solar Cycle 25 shape up? If history is any guide, the northern hemisphere of the sun will eventually catch up. For now, though, Solar Cycle 25 has a distinctly southern personality. Solar flares, y'all?

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Solar wind
speed: 370.8 km/sec
density: 4.1 protons/cm3
more data: ACE<https://services.swpc.noaa.gov/images/ace-mag-swepam-24-hour.gif>, DSCOVR<https://www.swpc.noaa.gov/products/real-time-solar-wind>
Updated: Today at 1804 UT
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X-ray Solar Flares
6-hr max: C1 1806 UT Dec05
24-hr: C1  0038 UT Dec05
explanation<https://spaceweather.com/glossary/flareclasses.html> | more data<https://www.swpc.noaa.gov/products/goes-x-ray-flux-dynamic-plot>
Updated: Today at: 1810 UT
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Daily Sun: 05 Dec 20[https://spaceweather.com/images2020/05dec20/hmi200.gif]<https://spaceweather.com/images2020/05dec20/hmi1898.gif>

Sunspot AR2790 produced a major M-class<https://spaceweather.com/glossary/flareclasses.html> solar flare on Nov. 29th. Since then it has grown quiet and seems to no longer pose a threat for strong flares. Credit: SDO/HMI
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Sunspot number: 38
What is the sunspot number?
<https://spaceweather.com/glossary/sunspotnumber.html>Updated 05 Dec 2020

Spotless Days
Current Stretch: 0 days
2020 total: 206 days (61%)
2019 total: 281 days (77%)
2018 total: 221 days (61%)
2017 total: 104 days (28%)
2016 total: 32 days (9%)
2015 total: 0 days (0%)
2014 total: 1 day (<1%)
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
2008 total: 268 days (73%)
2007 total: 152 days (42%)
2006 total: 70 days (19%)
Updated 05 Dec 2020

Thermosphere Climate Index
today: 5.98x1010 W Cold
Max: 49.4x1010 W Hot (10/1957)
Min: 2.05x1010 W Cold (02/2009)
explanation<https://spaceweatherarchive.com/2018/09/27/the-chill-of-solar-minimum/> | more data: gfx<https://spaceweather.com/images2020/04dec20/TCI_Daily_NO_Power_Percentiles.png>, txt<https://spaceweather.com/images2020/04dec20/tci_info.txt>
Updated 04 Dec 2020

The Radio Sun
10.7 cm flux: 103  sfu
explanation<https://www.ips.gov.au/Educational/2/2/5> | more data<https://services.swpc.noaa.gov/images/solar-cycle-10-cm-radio-flux.gif>
Updated 04 Dec 2020
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Cosmic Rays Solar minimum is underway. The sun's magnetic field is weak, allowing extra cosmic rays into the solar system. Neutron counts from the University of Oulu's Sodankyla Geophysical Observatory show that cosmic rays reaching Earth in 2020 are near a Space Age peak.

Oulu Neutron Counts
Percentages of the Space Age average:
today: +8.3% High
48-hr change: -0.9%[https://spaceweather.com/cosmicrays/downarrow_orange.png]
Max: +11.7% Very High (12/2009)
Min: -32.1% Very Low (06/1991)
explanation<https://spaceweatherarchive.com/2019/10/03/cosmic-rays-are-nearing-a-space-age-maximum/> | more data<https://cosmicrays.oulu.fi/>
Updated 05 Dec 2020 @ 0700 UT

[https://spaceweather.com/images2020/27nov20/oulu.png]<https://cosmicrays.oulu.fi/>

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Current Auroral Oval:

[https://spaceweather.com/POES/pics/usa_thumb.jpg]<https://services.swpc.noaa.gov/images/aurora-forecast-northern-hemisphere.jpg>

Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
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Planetary K-index
Now: Kp= 2  quiet
24-hr max: Kp= 2 quiet
explanation<https://www.spaceweather.com/glossary/kp.html> | more data
<https://www.swpc.noaa.gov/products/planetary-k-index>
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Interplanetary Mag. Field
Btotal: 4.6 nT
Bz: -2.5 nT south
more data: ACE<https://services.swpc.noaa.gov/images/ace-mag-24-hour.gif>, DSCOVR<https://www.swpc.noaa.gov/products/real-time-solar-wind>
Updated: Today at 1806 UT
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Coronal Holes: 05 Dec 20

[https://spaceweather.com/images2020/05dec20/coronalhole_sdo_200.gif]<https://spaceweather.com/images2020/05dec20/coronalhole_sdo_blank.jpg>
Solar wind flowing from this narrow coronal hole could reach Earth on Dec. 8th or 9th. Credit: SDO/AIA

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Noctilucent Clouds The northern-hemisphere season for noctilucent clouds has ended. The southern season begins in November. Between now and then, Earth has no noctilucent clouds.

[https://spaceweather.com/DAISY_PICS/daisy_thumb.gif]<https://spaceweather.com/DAISY_PICS/current_daisy.png>

Switch view: Europe, USA, Asia, Polar

Updated at:
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SPACE WEATHER
NOAA Forecasts
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Updated at: 2020 Dec 04 2200 UTC

FLARE
0-24 hr
24-48 hr
CLASS M
05 %
01 %
CLASS X
01 %
01 %

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Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active<https://spaceweather.com/glossary/geostorm.html>, minor storm<https://spaceweather.com/glossary/geostorm.html>, severe storm<https://spaceweather.com/glossary/geostorm.html>

Updated at: 2020 Dec 04 2200 UTC
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Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %

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High latitudes
0-24 hr
24-48 hr
ACTIVE
20 %
20 %
MINOR
20 %
20 %
SEVERE
10 %
10 %

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https://spaceweather.com

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