MALTA: A zonally averaged global atmospheric transport model for long-lived trace gases

It aims to be accessible to a broad community of users, with the primary function of quantifying emissions of greenhouse gases and ozone depleting substances. The model transport is derived from meteorological reanalysis data and flux-gradient experiments using a three-dimensional transport model.

Atmospheric sinks are prescribed loss frequency fields. The zonally averaged model simulates important large-scale transport features such as the influence on trace gas concentrations of the quasi-biennial oscillation and variations in inter-hemispheric transport rates. Stratosphere-troposphere exchange is comparable to a three-dimensional model and inter-hemispheric transport is faster by up to 0.3 years than typical transport times of three-dimensional models, depending on the metric used.