The Hamburg Atmosphere-Ocean Coupled Circulation Model

• Main Authors: E C H O-g, Stephanie Legutke, Reinhard Voss, Deutsches Klimarechenzentrum
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.605; http://www.mad.zmaw.de/fileadmin/extern/documents/reports/ReportNo.18.pdf

ECHO-G is a global coupled atmosphere-ocean climate model whose component models are the ECHAM atmosphere general circulation model and a global version of the Hamburg Ocean Primitive Equation model, HOPE-G, which includes a dynamic-thermodynamic sea-ice model with snow cover. ECHO-G can be used in numerical studies of natural variability of the world climate and of climate changes on time-scales ranging from the component models time steps to centuries. In high latitudes, the interaction between ocean and atmosphere can be strongly affected by the sea-ice cover. In particular, the heat flux through ice and that through leads and polynyas can differ by an order of magnitude on horizontal scales much smaller than that of a gridcell in global climate models. ECHO-G accounts for these effects by a separate calculation of fluxes over ice and over water when a sub-gridscale partial ice cover is present. Since the component models are used in their stand-alone versions with only some subroutine calls added, and since the coupling interface, OASIS, is a flexible tool that allows to change the number of component models, of interpolation methods, and data exchange frequencies by keyword specification, it should be relatively easy to include other models, or change the coupling strategy. This report describes the physical and technical aspects of a specific set-up that is in use at DKRZ. DKRZ ECHO-G Model Documentation