The physics of turbulence over Antarctic leads and polynyas and its parameterization: a joint study using observations, LES, and a micro-/mesoscale model

在海冰密度大的地区，总是有开放水域，根据形状的不同，称为铅或冰川。导线的长度从几公里到几十公里不等，宽度从几米到几公里不等。这些区域上方强烈的感热和潜热通量可以触发对流，从而显着改变大气边界层(ABL)。出于这个原因，铅被认为对极地海洋和大气之间的能量交换有很大影响。该项目的目标是更好地了解铅和多尼雅对边界层湍流的影响，并阐明它们对边界层能量收支和结构的重要性。LES结果和新的基于直升机的铅上方湍流观测将被用来(进一步)发展铅效应的参数化，它可以用于从微尺度非涡旋分辨率模式到天气预报和区域气候模式的不同网格尺寸的模式。这些研究将基于IMUK的Pi S和AWI之间之前的合作，其中使用了LES模型的简化版本，并为简单的铅形状开发了一个微尺度的非涡分辨模型。

In regions with large sea ice concentrations there are always open water areas called leads or polynyas depending on their shape. The length of leads varies between a few kilometres and tens of kilometres and their width ranges from several meters to kilometres. The strong sensible and latent heat fluxes above such areas can trigger convection which significantly modifies the atmospheric boundary layer (ABL). For this reason leads are supposed to have a large influence on the energy exchange between the polar ocean and the atmosphere. The goals of this project are to get a better understanding of the still not well understood effects of leads and polynyas on the boundary layer turbulence and to clarify their importance for the energy budget and structure of the ABL. LES results and new helicopter based observations of turbulence over leads will be used to (further) develop parameterizations of the lead effect which can be used in models with different grid sizes ranging from microscale non eddy resolving models to weather forecast and regional climate models. The investigations will be based on previous collaboration between the Pi s at IMUK and AWI, where a simplified version of the LES model was used and a microscale non eddy resolving model was developed for simple lead shapes.