Location
Yosemite National Park
Start Date
2-14-2014 12:55 PM
End Date
2-14-2014 1:25 PM
Description
The Heliophysics community needs to find out how gravitationally-trapped volatile matter is being lost from atmospheres by energetic processes, depleting them of key constituents, as has occurred most dramatically at Mars. This process is exemplified in geospace by the dissipation of solar energy to produce ionospheric outflows that feed back on dynamics of the solar wind interaction with Earth’s magnetosphere. Proposed mechanisms involve waveparticle heating interactions, upward ambipolar electric fields, or ponderomotive forces. Empirical guidance remains ambiguous concerning their relative importance. Moreover, it is unclear if the waves interact with particles primarily in a cyclotron resonant mode, in a lower hybrid exchange of electron (parallel) and ion (perpendicular) energy, or in a bulk ponderomotive mode. The questions raised by these issues include: Where do the waves that produce mass ejection grow? How do they propagate and transport energy? How can wave amplitudes, heating rates, and escape flows be derived from solar wind conditions? To obtain answers, it appears necessary to observe the magnetospheric and thermospheric boundary conditions applied to the topside ionosphere or exobase layer, and the response of ions and electrons to the ensuing battle between electrodynamic forcing and collisional damping.
Requirements for a Mission to study Thermosphere-Magnetosphere
Yosemite National Park
The Heliophysics community needs to find out how gravitationally-trapped volatile matter is being lost from atmospheres by energetic processes, depleting them of key constituents, as has occurred most dramatically at Mars. This process is exemplified in geospace by the dissipation of solar energy to produce ionospheric outflows that feed back on dynamics of the solar wind interaction with Earth’s magnetosphere. Proposed mechanisms involve waveparticle heating interactions, upward ambipolar electric fields, or ponderomotive forces. Empirical guidance remains ambiguous concerning their relative importance. Moreover, it is unclear if the waves interact with particles primarily in a cyclotron resonant mode, in a lower hybrid exchange of electron (parallel) and ion (perpendicular) energy, or in a bulk ponderomotive mode. The questions raised by these issues include: Where do the waves that produce mass ejection grow? How do they propagate and transport energy? How can wave amplitudes, heating rates, and escape flows be derived from solar wind conditions? To obtain answers, it appears necessary to observe the magnetospheric and thermospheric boundary conditions applied to the topside ionosphere or exobase layer, and the response of ions and electrons to the ensuing battle between electrodynamic forcing and collisional damping.