GENIE experiments

This page introduces a new way to configure and run traceable (i.e. reproduceable) GENIE experiments. We hope that this new method of approaching the organisation of GENIE files will make more sense to new users too.

The old way

By convention, the normal place for GENIE to output data is a directory outside of the genie source tree, normally at the same level as the top-level genie directory, called genie_output. When an experiment with experiment id 'my_experiment' is compiled and run using the confusingly named genie_example.job script (which is traditionally used to compile and run all GENIE model runs), a directory genie_output/my_experiment is made, and directories made within it for each GENIE component model (e.g. embm) to write data into.

So far, this is all very sensible, but then things get a bit confusing. The genie_example.job script generates namelist files od runtime parameters from the xml config file (or goin files in the soon-to-be-deprecated old way of specifying model configuration). These are used by the compiled executable so that it knows what configuration settings to run the model with (i.e. the details of the experiment you're doing, where to find input files, where to write output, whether or not do do x, or y etc). These namelist files (e.g. data_EMBM) and the executable are copied into genie_output/my_experiment and then the model is run from within the my_experiment directory. So, the my_experiment directory is more than just genie_output - it's in fact most of what you need to run the experiment. With the exception of a bunch of input files (topography, forcings etc), which are generally found within the source tree of the model, the location and details of which are specified in the config file, everything you need to run the experiment without the presence of the genie source tree is contained within my_experiment, along with the output data produced by the model.

There's nothing at all insensible about most of this - having the compiled model executable and namelist parameters along with the model output is good for traceability (in theory, if nothing in the source tree has been changed since you ran the experiment, you should be able to navigate to genie_output/my_experiment and launch genie.exe, and exactly reproduce your previous results. In practice, it's rarely that simple and there are some things we can do to improve traceability; but the main problem with the above is the misleading name of the genie_output folder and the difficulty of having it outside the source tree. Therefore we have made a new directory in the genie tree, called genie-experiments, from which experiments can be configured, built and run with relative ease and better traceability.

genie-experiments

The motivation behind the changes outlined here is to i) make GENIE easier to configure and run for new users by making it more obvious what's what and ii) to facilitate the creation of full traceable and portable (i.e. source-tree-independent) compiled experiments, which can be run manually (i.e. by executing genie.exe) or through a front end (e.g. the ALADDIN launchpad).