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Inbound CME

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http://www.thesurfaceofthesun.com/images/010114_eit_195.mpg
http://stereo-ssc.nascom.nasa.gov/browse/2010/08/01/ahead_20100801_euvi_195_512.mpg
http://sdowww.lmsal.com/sdomedia/ss...0100801_070003_aia_304__20100801_070002_m.mpg

FYI, those SDO and STEREO images of the last CME look remarkably similar to an event that was recorded by SOHO in January of 2001. The dark filament rises up into the atmosphere around the polar region until it reaches a critical point. At some point the whole thing blows and some sort of evaporation looking type of process occurs in the polar area. It's certainly an interesting type of CME.
 
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Michael Mozina said:
How about something describing currents *OUTSIDE* of the magnetosphere? Oh, and what the hell is a "magnetic bubble"?
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My specialty is magnetospheric physics, but there are also peeps looking at flux ropes in the solar wind and deducing the currents that flow in there using models that implicitly use electric currenst they are somewhere in this list.

A magnetic bubble is what it is and called after: a magnetic bubble; because the magnetic field is determining everything. It is a "blob" of plasma permeated with magnetic fields that had their origin in the sun, and these fields actually drive the currents in the "blob". The resistivity of the plasma dissipates the currents and thereby the magnetic field in the "blob" transforming magnetic energy into kinetic energy.
 
http://www2.nict.go.jp/y/y223/simulation/realtime/images/test_1.20100803171127.jpg

It's looks to me like the first hit peaked around 10:11AM California time, 17:11 UT. It seemed to result in a rapid rise in solar wind temperature and velocity, yet only a relatively small spike in density which dropped off again pretty quickly. The density spike a few weeks ago was much more dramatic, but there was no corresponding rise in velocity until a few days later, far after the density spike occurred. CME's definitely come in a variety of flavors. :)
 
tusenfem said:
The resistivity of the plasma dissipates the currents and thereby the magnetic field in the "blob" transforming magnetic energy into kinetic energy.
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And---tusenfem, is it correct to say that while both the magnetic field energy (integral of B^2/ (2 mu0)) and the kinetic energy (sum of 1/2 mv^2) may be large, the electric field energy (integral of epsilon_0 E^2/2) is never, ever large in these plasmas?
 
ben m said:
And---tusenfem, is it correct to say that while both the magnetic field energy (integral of B^2/ (2 mu0)) and the kinetic energy (sum of 1/2 mv^2) may be large, the electric field energy (integral of epsilon_0 E^2/2) is never, ever large in these plasmas?
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http://www.nasa.gov/mission_pages/themis/auroras/northern_lights.html
Angelopoulos was quite impressed with the substorm's power and he estimated the total energy of the two-hour event at five hundred thousand billion Joules. That's equivalent to the energy of one magnitude 5.5 earthquake .
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Michael Mozina said:
http://www.nasa.gov/mission_pages/themis/auroras/northern_lights.html
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In other words: nothing to do with the question.
The total energy in the CME is not large
Angelopoulos was quite impressed with the substorm's power and he estimated the total energy of the two-hour event at five hundred thousand billion Joules. That's equivalent to the energy of one magnitude 5.5 earthquake .
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... depending on your definition of large!
It is tiny in comparison with the total energy from the Sun that strikes the face of the Earth each second which is 1.74 * 10^17 Joules.
 
ETA: delete stuff I typed when I misread the number.

Anyway, as I said, that's magnetic field energy and particle kinetic energy, not electric field energy.
 
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Reality Check said:
In other words: nothing to do with the question.
The total energy in the CME is not large

... depending on your definition of large!
It is tiny in comparison with the total energy from the Sun that strikes the face of the Earth each second which is 1.74 * 10^17 Joules.
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ok, that's quite freaky some of the data on the wikipedia page, like that a thunderstorm releases about the same energy as the atomic bomb dropped on Hiroshima, but this is only about 10^13 Joules.
the biggest bomb ever detonated was 50MT, which is 2.1*10^17 Joules.

so the energy released in the biggest nuclear test ever is about the same as the energy the Earth receives from the sun every Second!

five hundred thousand billion Joules is 10^14 Joules.
 
I'm in Montana with clear skies right now, and I haven't seen anything yet. I'll stay up a couple of more hours to be sure...

ETA: According to Spaceweather.com, it seems that the Europeans got all the luck on this one :(
 
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ben m said:
And---tusenfem, is it correct to say that while both the magnetic field energy (integral of B^2/ (2 mu0)) and the kinetic energy (sum of 1/2 mv^2) may be large, the electric field energy (integral of epsilon_0 E^2/2) is never, ever large in these plasmas?
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True, it is the magnetic field that is driving the currents in the blob inductively through curl(B) ~ J and through the high mobility of the charges in the plasma any large scale electric field with quickly be negated. However, as I noted that there is Ohmic dissipation of the currents in the bubble, there is a dB/dt, which would lead to a curl(E), but as the time scales for this dissipation as so large, this E can well be neglected in the whole picture.

In the substorm that MM mentioned was a special case but has, indeed, nothing to do with a CME, that is the reconfiguration of the magnetotail after reconnection has started down the tail and the newly connected field lines shoot towards the Earth through the magnetic tension, thereby accelerating large amounts of plasma towards the Earth and setting up large current systems (see e.g. substorm current wedge) which drive Birkeland currents to the ionosphere and atmosphere, which create the aurora. Through the cameras that are all over Canada and Alaska we can estimate the power dissipated by looking at the aurora emissions.

This, unfortunately, is a rather convoluted press release again as they first talk about substorms and then suddenly about "magnetic ropes" making a direct connection between the Earth's "atmosphere" and the Sun. Later Dave Sibeck corrects this and talks about the "magnetopause" which makes a lot more sense than "atmosphere". But note, the rope that was seen by Themis was in May, whereas the event discussed by Angelopoulos was in March.

I think Vassilis and Dave would be well advised to actually READ what the press agency is putting on the web BEFORE it gets put on the web.
 
I'm in Montana with clear skies right now, and I haven't seen anything yet. I'll stay up a couple of more hours to be sure...

ETA: According to Spaceweather.com, it seems that the Europeans got all the luck on this one
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Nope

from the other thread


[FONT=Arial, Helvetica, sans-serif]GEOMAGNETIC STORM--MORE TO COME?[/FONT] The solar storm of August 1st sent two CMEs toward Earth. The first one arrived yesterday, August 3rd, sparking mild but beautiful Northern Lights over Europe and North America (see below). The second CME is still en route. NOAA forecasters estimate a 35% chance of major geomagnetic storms when the cloud arrives on August 4th or 5th.
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and this was last night in Michigan at Lake Superior
http://spaceweather.com/aurora/imag...one1.jpg?PHPSESSID=6sque912ujupm0g3al1j6qdlt7
- if we get a major hit - it will look more like this around S Ontario

and this in Ontario

http://spaceweather.com/aurora/images2010/04aug10/Robert-Snache1.jpg
 
Good thing I didn't try to stay up late last night.

My browser at work is painful to deal with. Does the spaceweather site indicate when and where the good viewing will be? I'd like to plan my evening here in New Hampshire.
 
Soapy Sam said:
Did anyone here actually observe anything related to this?
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Not me, Dublin is at ~50° g latitude, so not much chance. Plus the weather was awful yesterday. A friend of mine in Donegal did see the aurora last night and is planning to watch again tonight.
 
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