#11 Non-BFB test

Abstract

An important category of testing method is currently missing in the ACME test suite: tests that determine whether non-bit-for-bit result changes are climate changing or not. We have developed a new method to test the solution reproducibility using the concept of time step convergence (TSC). The basic idea is that when the model equations have changed or when the code is not compiled/exercised correctly, the results will not converge to the reference solutions produced by a trusted model on a trusted computing environment.

This poster introduces the new method and shows examples of test results using CAM5.3 which is very similar to the atmosphere component of the ACME V0 model. The new TSC test is objective, easy to implement, and computationally efficient. We expect that the same methodology can be used for other components of the ACME model, and would be interested in discussing this with colleagues from other groups.