The subject of the project are interactions between the atmospheric and oceanic boundary layers and sea ice, with special interest in fragmented, strongly heterogeneous sea ice cover typical of, but not limited to the so-called marginal ice zone (multiple ice floes of different sizes; leads and cracks), as well as first stages of sea ice formation. The overarching leitmotiv integrating the individual project tasks are larger-scale effects of local, small-scale processes related to the spatial and temporal inhomogeneity of sea ice properties. Several of those effects have been studied by the team of the Principal Investigator in the last years, and therefore many aspects of the proposed research are a natural continuation of the already completed and ongoing work. In particular, on the list of the project objectives below (and further throughout this document) reference is made to the results obtained within the project "Discrete-element sea ice modeling – development of theoretical and numerical methods" (funded by the Polish National Research Centre; 07.2016–01.2020; project number 2015/19/B/ST10/01568; see project page). The main objectives of the new project are:

1. To apply Unmanned Aerial Vehicles (UAVs) to collect a wide range of observational data from the ice/water surface and the atmospheric boundary layer (ABL) over fragmented sea ice in the Baltic Sea. To perform the UAV surveys in different ice and weather conditions in order to obtain data suitable for validation of numerical models and for an analysis of the dynamical processes within the ABL related to different spatial distributions of ice floes and open water areas.
2. To use the collected observational data and the validated WRF (Weather Research and Forecasting) model to improve our understanding of the interactions between nonhomogeneous sea ice and lower atmosphere; in particular, to investigate how the size and spatial distribution of different sea ice features determine the ABL structure.
3. To verify the hypothesis – formulated based on the results of idealized numerical modeling obtained within the project currently under realization – that sea ice concentration alone is not suffcient to determine the area-averaged properties of the ABL and the turbulent ocean{sea ice–atmosphere heat and moisture exchange. To the contrary, the subgrid-scale spatial distribution of sea ice floes, cracks and leads, through its influence on the three-dimensional (3D) ABL circulation and on details of convective processes, heat and momentum fluxes, turbulence, vertical stability etc., modifies area-averaged ABL characteristics.
4. To develop parameterizations, similar to the existing so-called mosaic methods, of the surface heat fluxes through a fragmented sea ice cover, suitable for implementation in WRF and other Numerical Weather Prediction (NWP) models.
5. To develop the code of a 'multi-phase' model suitable for high-resolution simulations of coupled ocean–sea ice–atmosphere dynamics, based on the models developed within the currently running project and the available open-source Computational Fluid Dynamics (CFD) models. To use the coupled model to analyze the dynamics of the upper ocean/lower atmosphere during initial stages of sea ice formation, with particular interest in formation of so-called frazil streaks – elongated bands of high concentration of frazil cristals – and their role in turbulent ocean–atmosphere momentum and heat exchange. Thus, to improve our understanding of a process that is only rudimentarily taken into account in present sea ice models.
6. To implement new features in the coupled sea ice–wave model, developed within the current project, and to apply this model to analyze various mechanisms of wave attenuation in the Marginal Ice Zone (MIZ), including floe–floe collisions, under-ice skin and form drag, inelastic dissipation within the ice, and turbulence.

A full description of the project can be found here.
A short popular-science summary is here.