COSMO-IL Model operational applications at IMS

Last updated: 22 Aug 2018

1. Introduction

COSMO-IL is the IMS operational model with 2.8 km resolution. The model runs on 18 nodes with 32 AMD cores (total: 576 cores) allocated on a SGI machine with 44 nodes.

For the interpolation of the lateral boundary fields, additional 10 cores are used. The global IFS (Integrated Forecast System) model from ECMWF provides the driving lateral boundary fields for COSMO-IL.

2. Basic model setup

The integration domain of COSMO-IL with 0.025° resolution (~2.8km) covers the East Mediterranean (Fig. 1). It has 561x401 grid points and 60 vertical levels. The lowest level is 10 meters above ground and the heights level is ~23 km, the grid is not rotated (pollat=90° and pollon=-180°). The coordinates of the lower left and the upper right corner of the integration domain are  lon=25°E, lat=26°N and lon=39°E, lat=36°N, respectively.  

Fig. 1: COSMO domain used at IMS

Figure 1: COSMO domain at IMS

3. Details of configuration

In order to achieve high skill for precipitation it was found that the shallow convection scheme should be turned off. However, the cost is a reduction in temperature skill. Therefore, the model runs in different namelist settings to optimize precipitation skill on rainy events and not to harm the temperature skill at dry events. Furthermore, it was found that different settings optimize the models skill for summer and winter.  Table 1 and 2 shows the 4 different configurations which are determined by IFS forecast and the current date.