Constraining the magnetic connection of Jupiter's and Saturn's ring planes with their stratospheres

点击翻译按钮获取中文摘要

Saturn’s spin-symmetric magnetic field provides a natural coordinate system mapping any latitude of the middle atmosphere to corresponding locations in the ring plane. So-called conjugate latitudes and ring-plane conjugates have been proposed for the first time by Connerney in 1982. His Z3 model provides a quantitative description of connection between mid atmosphere latitudes with locations in the ring plane. High charge-to-mass-ratio particles which are confined to motion along field lines are subject to mass transport from the ring plane into the neutral atmosphere and may therefore lead to ring erosion and mass loss. This mass transport (mainly water) would also play an important role in the chemistry of the middle atmosphere (oxygen supply) and would be a tracer for constraining the meridional circulation. Up to now there is no direct proof of the possible transport of water and the related mechanisms of its distribution. Instead variations in the haze density of the lower stratosphere have been used to constrain the mass transport. This is a very indirect method, since it requires insight into the microphysics of condensation nuclei of unknown nature and leaves of lot of space for speculations about the fate of the water transported from the rings into the middle atmosphere. Herschel will for the first time provide highly resolved observations of the vertical profile of water vapour in the middle atmospheres and its meridional distribution in late 2009 / early 2010 and therefore provide a strong constraint for the proposed connection processes. It is the goal of this application to analyse these observations with respect to the magnetic ring plane – middle atmosphere connections.