engleski

On Nature, Theory, and Modelling of Atmospheric Planetary Boundary Layers

Planetary boundary layers (PBLs) represent sensitive and changeable coupling agents that regulate the fluxes of energy, momentum, and matter between the atmosphere and land or sea over a range of scales, from local to global. Numerical weather prediction (NWP), climate, air pollution, and coupled atmosphere–hydrosphere–biosphere models all include PBL schemes as submodels. With the development of high-resolution models, requirements for PBL schemes have dramatically increased, making them a key element of modern model suites that address essential environmental features. Further advancements in this field are stymied, however, as long as the surface boundary conditions provided by PBL schemes remain uncertain.

Air-sea-ice interactions; Prandtl number; Richardson number; turbulence closure

This peer-review essay summarizes the current state-of-the-art, provides a view on the immediate needs and tentative remedies in the boundary-layer theory, measurements and modeling. Overall analysis was initiated by the NATO Advanced Research Workshop on Atmospheric Boundary Layers: Modelling and Applications to Environmental Security. The BORA project was much stimulated by, and addressed further, the developments and results presented in this paper.