权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Representation of the convective atmospheric boundary layer during cold-air outbreaks in regional models: a joined study based on observations, Large Eddy Simulation and mesoscale modelling

区域模式中冷空气爆发期间对流大气边界层的表征：基于观测、大涡模拟和中尺度建模的联合研究

基本信息

批准号：
171803021
负责人：
Dr. Christof Lüpkes
金额：
--
依托单位：
Institut für Meteorologie und Klimatologie
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/171803021?language=en
关键词：
Representation convective atmospheric boundary layer

项目摘要

The interaction between atmospheric processes in polar and mid-latitude regions is strongly affected by cold-air outbreaks (CAOs). During such events cold air originating from (sea)ice covered regions is transported over large distances towards lower latitudes, while over open water a shallow but strongly heated convective boundary layer develops. Although the present generation of weather and regional climate models captures CAOs qualitatively well, there are deficiencies caused by uncertainties in the representation of the multi scale physical CAO processes in models. Open questions concern e.g., the generation of rolls under conditions of strong thermal forcing over the open and partially ice covered ocean and under nonstationary synoptic conditions. Other questions are related to the parameterization of the strong turbulent fluxes, especially in coarse grid resolution. Hence this project aims to study the physical processes in polar CAOs with roll vortices using large eddy simulation (LES) and mesoscale modelling. Furthermore, parameterizations of turbulence in CAOs will be improved with a focus on the most modern low order closures and their applicability to regional scale models. To this end current and new closures are used in a mesoscale model with different resolutions and its results are compared with observations and with the results of LES.

极地和中纬度地区的大气过程之间的相互作用受到冷空气爆发（CAO）的强烈影响。在这种情况下，来自（海）冰覆盖地区的冷空气被输送到较低纬度的大距离，而在开阔水面上，一个浅但强烈加热的对流边界层发展。虽然目前这一代的天气和区域气候模式捕捉CAO定性好，有不确定性造成的多尺度物理CAO过程中的模式表示的不足之处。未决问题涉及，在开阔和部分冰覆盖的海洋上，在强热力强迫条件下，以及在非平稳天气条件下，卷的产生。其他问题与强湍流通量的参数化有关，特别是在粗网格分辨率下。因此，本项目旨在利用大涡模拟（LES）和中尺度模拟研究具有滚转涡的极地CAO中的物理过程。此外，CAO中湍流的参数化将得到改进，重点是最现代的低阶闭合及其对区域尺度模式的适用性。为此，目前和新的封闭中尺度模式中使用不同的分辨率和它的结果与观测和LES的结果进行了比较。