SYSTER

This proposal is for a multi-payload sounding rocket study of Joule heating in the auroral region.

The instrumentation on the rocket will measure local parameters governing the energetics of the lower thermosphere and controlling the coupling between the ionized plasma and the neutral atmosphere.

Scientific questions to be addressed by SYSTER are: - what is the altitude distribution of the Joule heating in the evening sector of the auroral zone?- how well do the different estimates of the heating agree with each other?

What are the sources of discrepancies, if any?- what is the contribution of small scale structuring in plasma, currents and electric fields to the energetics of the lower thermosphere?To address these questions, we propose in situ instrumentation to measure, in the altitude range of 100…180 km, electric and magnetic fields, electron concentration and temperature, neutral winds and ion drifts, and precipitation of auroral and high energy electrons.

The data will be used for quantitative reconstruction of the Joule heating altitude profile.

The context of the auroral situation will be provided by the ground-based measurements using radars and optical instruments.The SYSTER scientific objectives are closely related to the questions to be addressed by the ESA Daedalus mission candidate for EE10.

While Daedalus mission was not selected, discussions are ongoing between ESA and NASA aroundthe lower thermosphere-ionosphere in situ satellite mission, so the SYSTER science is highly relevant and timely.