Truncation error estimates for refinement criteria in nested and adaptive models

A simple method for calculating the truncation error at any time during an integration is described. Two cases using the shallow-water equations and the hydrostatic primitive equations are examined to demonstrate the accuracy of the method and illuminate the relationships among the truncation error, a particular discretization, the equations being solved and the flow physics. The relationship between the truncation error and the solution error is also discussed and it is argued that minimization of the truncation error is the necessary consideration for producing more accurate numerical solutions. -from Author