Efforts to integrate Geographic Information Systems (GIS) and environmental simulation models often fail due to the structure of current GIS which do not meet the requirements of complex numerical simulation techniques. Therefore research in the field of environmental modeling focuses on adequate flexible simulation methods and powerful interoperable GIS interfaces to implement these methods. This contribution shows approaches towards an interoperable object-oriented GIS interface for atmospheric modeling and analysis. The architecture and specifics of a first prototype system, called AtmoGIS, are presented.