Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-L] lightning



So there's a plasma, with positive ions drifting one way and free electrons the other?


Temperatures inside lightning can exceed 25 kK.
You will have N_2^+, N+, O_2^+, and O^+ as the dominant charge
carriers. Equilibrium constants are temperature dependent, leaving O
and N with appreciable partial pressures. This leads to the subsequent
formation of O3, NO, and NO2.

Dr. Roy Jensen
(==========)-----------------------------------------¤
Faculty Lecturer, Chemistry
E5-33A, University of Alberta
780.248.1808


On Wed, 12 Jun 2013 18:30:15 -0500, you wrote:

I'm writing an in-house summary article on lightning for a fall semester class that's part of a weather unit. I've looked in a basic meteorology text and at (the ever-present) Wikipedia, and I'm a little puzzled by one aspect of a lightning strike. Here's what Wiki-P says:

"Once a conductive channel bridges the air between the negative charges in the cloud and the positive surface charges below, the flood gates are opened, and a massive electrical discharge follows. Neutralization of positive surface charges occurs first. An enormous current of positive charges races up the ionic channel towards the thundercloud."

Previous to this the Wiki-P article mentions the negatively charged bottom of the thunderhead inducing positive charge (which I take to mean the polarization of charge between surface and sub-surface) of the earth, but this "current of positive charges" racing upward has me puzzled. What are these positive charges, oxygen ions? This explanation sounds fishy/wrong to me, but I've never studied lightning or the literature about it. If someone has a better explanatory source, I would appreciate it.
_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l