期刊名称：Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN：1600-0870
出版年度：2018
卷号：70
期号：1
页码：1-16
DOI：10.1080/16000870.2018.1548869
摘要：Within their domain, regional climate and weather forecasting models deviate from the driving data. Smallscale
deviations are a desired effect of adding regional details. There are, however, also deviations of the
large-scale circulation, which can be caused by orographic effects and depend on the large-scale flow
condition. These ‘secondary circulations’ (SCs) are confined to the model domain due to the prescribed
boundary conditions. Here, the impact of different regional model configurations on the SC is analysed in a
case study for the European region using an ensemble approach. It is shown that at 500 hPa, vortices of the
SC have diameters on the order of several thousand kilometres and are related to wind speed anomalies of
more than 5 m/s and geopotential height anomalies of more than 5 dam. The spatial structure and the
amplitude of the SC strongly depend on the location of the lateral boundaries. The impact of the boundary
location on the anomalies is on the same order of magnitude as the anomalies themselves. The resolution of
the regional model, as well as the application of spectral nudging and a smoothed topography, affects mainly
the amplitude of the SC, but not the spatial structure.
关键词：Limited area model ; regional climate model ; COSMO-CLM ; secondary circulation ; boundary effects ; orographic effects
