Abstract. The Met Office Unified Model (UM) is a state-of-the-art
weather and climate model that is used operationally worldwide. UKCA is the
chemistry and aerosol sub model of the UM that enables interactive
composition and physical atmosphere interactions, but which adds an
additional 120 000 lines of code to the model. Ensuring that the UM code and
UM-UKCA (the UM running with interactive chemistry and aerosols) is well
tested is thus essential. While a comprehensive test harness is in
place at the Met Office and partner sites to aid in development, this is not
available to many UM users. Recently, the Met Office have made available a
virtual machine environment that can be used to run the UM on a desktop or
laptop PC. Here we describe the development of a UM-UKCA configuration that
is able to run within this virtual machine while only needing 6 GB of memory,
before discussing the applications of this system for model development,
testing, and training.
Simplification of array access patterns for compiler optimizations
