Title:  The influence of misrepresenting the stable nocturnal boundary layer on the daytime development of convection.

Supervisors: Bjorn Stevens & Marco Giorgetta.

Project: HD(CP)2 : High Definition Clouds and Precipitation for advancing Climate Prediction (


My PhD focuses on the influence of the stable nocturnal boundary layer (NBL), and the effect of not correctly representing it in (low resolution) large-eddy simulations (LES), on the daytime development of convection.


The representation of turbulence in the NBL requires extremely high spatial resolutions, O(1m). Although failure to represent the turbulent eddies of the NBL can greatly distort the vertical coupling of the surface to the atmosphere, relatively little is known about the effect of such biases for the subsequent daytime evolution of the boundary layer. Is the diurnal development of convection influenced by a poor representation of the NBL?

Using two LES codes (the established UCLA-LES, and newly developed ICON-LES) at a variety of resolutions, and for different case studies ranging from idealized diurnal evolutions to cases observed during the HD(CP)2 HOPE campaign, this question will be systematically explored. In so far as necessary, simple parametrizations will be proposed for the ICON-LES that minimize those biases in the NBL period.


last update: 18.06.2014