The highly structured
Modular Earth Submodel System (MESSy)

developed by the consortium of

DLR-logo KIT-logo FZJ-logo MPIC-logo CYI-logo FUB-logo UniMZ-logo UniConn-logo CMA-logo IGCE-logo UHH-logo MIUB-logo.jpg AUTH-LAP-logo.jpg wur-logo.png TU_Delft_logo_RGB.png UAarhusGD-logo.jpg SYSU_logo.jpg KAUST_logo.png

and supported by


Deutsches Klimarechenzentrum (DKRZ), Hamburg, Germany

MPG Rechenzentrum (RZG), Garching, Germany

Leibniz Rechenzentrum (LRZ), Garching, Germany


The Modular Earth Submodel System (MESSy) is a software providing a framework for a standardized, bottom-up implementation of Earth System Models (or parts of those) with flexible complexity. "Bottom-up" means, the MESSy software provides an infrastructure with generalized interfaces for the standardized control and interconnection (=coupling) of "low-level ESM components" (dynamic cores, physical parameterizations, chemistry packages, diagnostics etc.), which are called submodels. MESSy comprises currently about 60 submodels (i.e., coded MESSy conform):

MESSy is a multi-institutional project.

The main design concept of MESSy is the strict separation of process description (=process and diagnostic submodels) from model infrastructure (e.g., memory management, input/output, flow control, ...).

Within MESSy, the operator splitting is formalized as the fundamental concept. Model codes are organized in 4 conceptual software layers, object oriented approaches are utilized as far as possible in the used programming language standard, and as far as feasible with respect to the computational performance.

The MESSy approach offers several benefits: A scalable model development is achieved and several different implementations of processes and diagnostics can coexist in the same model code. Nonetheless, the overall complexity remains controllable in a transparent and user friendly way. A high flexibility is achieved through the modularity, providing a research tool for a large community serving a wide variety of scientific needs.

The concepts of MESSy are summarized on this poster: MESSy_poster_v7.pdf


MESSy is NOT messy! You might ask, why we have chosen an acronym with such a negative touch ... ? Well, we did this on purpose - to be self-ironic and a little provocative to make people think about it - about how models have been so far ... And it seems to work ...!
Note of caution: The MESSy submodels listed on this web-site (MESSy Submodels) include contributions from many modelers in several institutions. It is important that developers and contributors to submodels are properly credited and informed. You are requested to follow the guidelines as indicated with the submodels. In case of doubt, errors, or disagreements, please contact the Consortium Steering Group (see MESSy Licence).
This page was last modified on 06 Jun 2017.
If you have comments or suggestions, e-mail me at Patrick.Joeckel@dlr.de  !