Energy conversion boundaries

neutrals and ions

Ionospheric Layers

Ionospheric Layers Effective dynamo ~ dayside E-layer E: dynamo (only electrons can move freely due to i-n collision)  EM energy to Joule heating & geomagnetic induction F: highest density (highest energy absorption of solar EUV) but i-n collision is not sufficient  important for ion escape D: lowest layer of EUV heating (below is mesosphere with low-temperature)  mixing to non-mixing

Electron Density due to EUV < 102.7 nm The conductivity at a given height is proportional to the electron number density Ne. In the dynamo region the ionospheric plasma is largely in photochemical equilibrium. The dominant plasma species is O+2, which is produced by photo ionization at a rate J (s−1) and lost through recombination with electrons. N = √(J α-1 cos(χ))

E-layer as energy conversion boundary

Solar-Quiet (Sq) day ionospheric current system @ E-layer . Morning Evening A current system in the ionosphere is created and maintained by solar EUV radiation The magnetic effect of this system was what George Graham discovered

 since semi-static energy balance determines location of layer, it is strongly affected by the other element such as precipitating particles.

irregularity by precipitation

irregularity by precipitation Ne Te Ti Vi 36 hour data (EISCAT)

Atmospheric surfaces

Mesopause: stratified structure to possible convection layer  UV absorption by O3 below Tropopause: highest boundary of convection  UV absorption by O3 above It is not composition or force balance but the form of energy conversion that determines the mesopause/tropopause  dynamics/convection can easily modify the boundary

spin-off: Chapman-Ferraro current

spin-off: Chapman-Ferraro current If the motor-dynamo transition is considered as ”boundary layer”, the cusp is the kind of boundary layer from dayside interaction to nightside interaction.  ion dynamic can modify the boundary location

deceleration makes a pair of J//  We don’t need acceleration part to produce a pair of charge

detecting motion of “boundary” cusp Newell et al., 2010, JGR

Mass-loading boundary Plasma mantle is the largest source of the field-aligned current  solar wind is decelerated there inside the magnetopause  we need deceleration mechanism: due to mixture of escaping ions! Due to 16 time heavier mass of O+ than H+. the mass-loading of 0.1 cm-3 O+ to 10 cm-3 magnetosheath flow results in about 14% (=16/116) loss of velocity.

Mass-loading boundary Therefore, the Earth’s plasma mantle can be considered as boundary from magnetospheric ion regime to solar wind ion regime, which is equivalent to mass-loading. To have plasma mantle “mass-loading” boundary layer, escaping ions is inevitable, and this could be the reason why we have not found the plasma mantle for the Martian “cusp”