This book is the fifth volume in a series of books on Earth System Modelling (ESM) infrastructure and builds on the content of the earlier volumes.The book begins at the point where the issues of the scientific contents of models have reached a level of maturity and codes have been developed (see Vol. 2), coupling technologies and techniques exist (see Vol. 3), and mechanisms for getting data into and out of models (i.e. I/O and archiving systems) are available (see Vol. 4). Now, in the context of a process of continuous improvement and development of scientific codes and software infrastructures, scientists are in a position to construct and run computational experiments to investigate specific scientific questions.