Turbulence interactions in Earth's atmospheric boundary layer: A scale-crossing approach to disclose transport processes near the surface

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The Earth's atmosphere and land regulate each other through bi-directional exchange processes. Weather and climate forecast models are built on a mechanistic understanding of that interaction. The forecast and theory work well in case of well-developed turbulence in the atmospheric boundary layer, but become unreliable towards more stable conditions. Atmospheric stability is very common when the contribution of convection diminishes, for example at night. Complementary theory is needed to describe the mechanisms that contribute to turbulent mixing in the stable case, which first requires an evolution of methodologies to observe and classify the (non-)turbulent processes near the surface. This project aims to bring together novel methods for the observation and characterization of the weakly understood near-surface processes in the (stable) atmospheric boundary layer. With a high-resolution in-situ sensing cube (20x20x5m) inside a remotely-sensed virtual box (500x500x1000m) we can observe motion and temperature structures simultaneously in space and time. This scale-crossing approach is key to elucidate the intermittent, mixed and spatially heterogeneous motions found near the surface in the atmospheric boundary layer. Second, novel stochastic data-mining methodologies are applied to these real-life data for a characterization of (non-)turbulent events and the turbulent mixing these cause. The scientific merits are a ground-braking approach for the validation of fluid-dynamic and earth-system models, that contributes to an improved understanding of the land-atmosphere interface we live in.