  A meteoroid penetrating the Earth's atmosphere leaves behind a trail of dense
plasma in the E-region ionosphere, a region where electrons are strongly
magnetized while ions are demagnetized due to their frequent collisions with
neutrals. While radar measurements of meteor trail evolution have been
collected and used to infer meteor and atmospheric properties since the 1950s,
no accurate quantitative model of trail fields and diffusion exists. This paper
describes a theory and simulations of trail plasma physics which applies to the
majority of small meteors. Unlike earlier papers, our theory assumes a
significant angle between the geomagnetic field and the plasma trail and
includes the important interaction between the trail and the background
ionospheric plasma. This study provides quantitative knowledge of the spatial
distribution and dynamics of the plasma density and electric field. This should
enable meteor and atmospheric researchers to more accurately interpret radar
observations of specular and non-specular meteor echoes.
