Earth Radii Used in Numerical Weather Models

摘要

In the development of numerical atmospheric models, many simplifying assumptions are made. One of the simplifying assumptions is that the Earth can be represented as a sphere. This assumption greatly simplifies the complexity of the resulting equation set that needs to be solved and makes them more tractable. It also reduces the computational cost. The Synthetic Environmental Data Representation and Interface Specification (SEDRIS) Spatial Reference Model (SRM), ISO/IEC 18026, defines a conceptual model and the methodologies that allow the description, and transformation or conversion, of geometric properties within or among spatial reference frames. This paper serves to document the values used for the Earth's radius by several operational numerical atmospheric models for use in the SRM.