Estimating numerical errors due to operator splitting in global atmospheric chemistry models: Transport and chemistry

TL;DR

This paper provides upper bounds on numerical errors from operator splitting in global atmospheric chemistry models, highlighting more accurate strategies and quantifying error margins in simulations.

Contribution

It introduces bounds for operator splitting errors in atmospheric models and compares strategies, demonstrating improved accuracy with specific methods.

Findings

Operator splitting strategies evaluating chemistry at the end are more accurate.

Different splitting strategies differ by at most 10% in simulations.

Similar error bounds are found in global CTM simulations.

Abstract

We present upper bounds for the numerical errors introduced when using operator splitting methods to integrate transport and non-linear chemistry processes in global chemical transport models (CTM). We show that (a) operator splitting strategies that evaluate the stiff non-linear chemistry operator at the end of the time step are more accurate, and (b) the results of numerical simulations that use different operator splitting strategies differ by at most 10 percent, in a prototype one-dimensional non-linear chemistry-transport model. We find similar upper bounds in operator splitting numerical errors in global CTM simulations.