Could a planet's atmosphere produce flares?

[jack476]

< Mentor Note -- thread moved to General Physics from the Earth forum for better views >

I put this in Earth Science because it pertains to atmospheric physics, astronomy might be more appropriate. I'm enrolled to take an advanced magnetism course this upcoming semester and I've been looking through the textbook, a section that caught my interest was a note about solar flares.

A solar flare is caused by energy stored in the Sun's magnetic field suddenly being released, carrying charged particles from the Sun's atmosphere with it. Planets also have ionized gas in their upper atmospheres, and they also have rotating magnetic fields.

My question, then, is whether or not it could be possible for a planet to also produce very small mass ejections from its ionosphere. Could a planet's magnetic field start becoming more concentrated in certain area followed by a discharge carrying away particles from the ionosphere in the same fashion. If not, what would it take?

Just curious. Thanks!

 

[davenn]

My question, then, is whether or not it could be possible for a planet to also produce very small mass ejections from its ionosphere. Could a planet's magnetic field start becoming more concentrated in certain area followed by a discharge carrying away particles from the ionosphere in the same fashion. If not, what would it take?

have never heard of such and couldn't imagine it happening

The source of solar flares is from sunspots ( there is nothing like that on the earth)
these sunspots are regions highly concentrated magnetic fields ( there is nothing like that on the earth)
The flares occur when the magnetic fields within those sunspot groups ( also known as active regions)
start becoming very complex and twisted and contorted. When the magnetic fields can no longer remain stable, because of those contortions,
the field snaps and collapses and all the energy and plasma material being held within the field is suddenly released in a flare.

This blast of energy ( X-rays, broadband radio waves, visible and UV light) and plasma, primarily ionised Hydrogen atoms ( protons) surge out into space. The X-rays and other stuff in that list get to Earth in around 8 minutes ( traveling at the speed of light) and cause radio blackouts because of the effects on the ionosphere. The plasma blast is called a CME ( Coronal Mass Ejection) and is traveling much slower 600 - 1200 km/sec. these cause what are called Proton Events in the polar regions of the Earth as those particles are trapped my the Earth's magnetic field and are funnelled down to the magnetic poles. ( close enough to the geographic poles). This causes PCA's Polar Cap Absorption events causing further radio comm's disruptions and also aurora displays as they have over the last few daysThe Earth's magnetic field just isn't strong or concentrated enough to cause anything like thischeers
Dave

 

[davenn]

OK here's a couple of pix of the sun at the moment

the first one is a Hydrogen Alpha view and is very close to what you would see visibly through a telescope with a special filter to cut out most of the intense sunlight
This sunspot group has been causing a few flares over the last week and producing CME's resulting in aurora

courtesy of Mt. Wilson Observatory 150-ft Solar Tower:This next image is of the same section of the sun using a detector that can detect an ionised Iron ( Fe) wavelength
with this one you can clearly see the magnetic field lines and loops being "traced out" by the plasma being held in the
magnetic fields ( just like when you put a bar magnet under a sheet of paper and sprinkle iron filings on top
maybe you did that at school in days gone by ?

courtesy of Solar Dynamics Observatory (SDO)cheers
Dave

 

[jack476]

Oh, very cool. Thank you!

So is it just a matter of rocky planets not being able to have powerful or active enough magnetic fields? Or is it something specifically different in how the atmospheres of stars work vs those of planets?

 

[davenn]

Or is it something specifically different in how the atmospheres of stars work vs those of planets?

yes, the sun and other stars have a very complex magnetic field system. And it isn't just the solar atmosphere or surface. The magnetic fields are generated deep within the sun and what we see as sunspots is just the visible manifestation of where those fields break through the suns surface ( photosphere).

here's a bunch of links for you to have a read through that talk about the solar cycle, magnetic fields and related things

http://csep10.phys.utk.edu/astr162/lect/sun/magnetic.html

https://en.wikipedia.org/wiki/Sunspot

http://www.space.com/11506-space-weather-sunspots-solar-flares-coronal-mass-ejections.html

http://www.windows2universe.org/sun/atmosphere/sunspots_subsurface_mag_field_gsfc.html
( this animation shows what I spoke about with the deep fields penetrating the surface)There's lots more, but those will keep you out of trouble for a while

cheers
Dave