Leaky Atmosphere: Earth's Magnetic Field Driving Oxygen Away

[wolram]

http://www.sciencedaily.com/releases/2008/08/080828090715.htm

ScienceDaily (Aug. 28, 2008) — Oxygen is constantly leaking out of Earth’s atmosphere and into space. Now, ESA’s formation-flying quartet of satellites, Cluster, has discovered the physical mechanism that is driving the escape. It turns out that the Earth’s own magnetic field is accelerating the oxygen away.

 

[gdp]

http://www.sciencedaily.com/releases/2008/08/080828090715.htm

ScienceDaily (Aug. 28, 2008) — Oxygen is constantly leaking out of Earth’s atmosphere and into space. Now, ESA’s formation-flying quartet of satellites, Cluster, has discovered the physical mechanism that is driving the escape. It turns out that the Earth’s own magnetic field is accelerating the oxygen away.

Not entirely correct. Since the magnetic force is always perpendicular to a charged particle's velocity (displacement per unit time), a magnetic field cannot by itself do any work on a charged particle (work = force dot displacement), because the dot-product of the magnetic force and the particle's velocity is necessarily identically zero.

It is the electric fields induced by the changes in the Earth's magnetic field as it is deformed by changes in solar wind pressure and by various transient plasma instabilities that are actually responsible for accelerating the oxygen ions away from the Earth.