Whitepaper #321 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: space weather research/applications/operations pipeline; planetary ionospheres / upper atmospheres; […]
To understand the Earth’s atmosphere-space transition region, direct, high-resolution measurements of several key parameters are required to reveal the characteristics and energy exchange within the lower ionosphere/thermosphere. This white paper discusses the science motivation for gathering this fundamental knowledge which motivates new missions with satellites and sounding rockets.