DRivers and Impacts of Ionospheric Variability with EISCAT-3D (DRIIVE)

One of the biggest unanswered questions in the solar-terrestrial science that underpins Space Weather research is:

How does the high latitude ionosphere vary on small scales in response to driving from above and below?

An immediate practical follow-on question would be: what are the impacts of small-scale processes to the larger upper atmosphere environment? The answers to these questions are essential for understanding how Space Weather impacts on society. This area is of growing importance to the UK, as evidenced by recent investment in operational Space Weather forecasting at the Met Office and the inclusion of Space Weather in the National Risk Register.

To answer these questions, we need to understand the processes that occur in the region known as the Mesosphere-Lower Thermosphere-Ionosphere (MLTI - 75-200 km altitude) and how they affect the wider coupled ionosphere-upper-atmosphere system. The ionosphere and upper neutral atmosphere are intrinsically linked: perturb one and the other changes. This has implications for our near-Earth space environment where variations in atmospheric density produce changes in the orbits of space debris, increasing the risk of unforeseen collisions; a significant natural hazard as Geospace grows more crowded. Space Weather plays a big role in modifying this region through frictional Joule heating and particle energy deposition but is not the only important driver. The weather in the lower atmosphere drives changes in the ionosphere that can be comparable to external forcing, but the relative contribution is far from understood, as the processes are under-observed. Another barrier to knowing that contribution is our inability to properly account for small scale variability, whether driven from above or below. Upper atmosphere models typically do not resolve this variability, yet we know that not doing so leads to underestimates of the magnitude of atmospheric heating by as much as 40%. This heating is a process that relies...