The ALMA data exchange convention

The ALMA data exchange convention

To facilitate the exchange of forcing data for land-surface schemes and the results produced by these schemes, ALMA (Assistance for Land-surface Modelling activities) proposes to establish standards. The aim is to have a data exchange format which is stable but still general and flexible enough to evolve with the needs of land-surface schemes. This should ensure that the implementation of procedures to exchange data only needs to be done once and that future inter-comparisons of land-surface schemes will be run more efficiently.

The present web pages try to justify the choices made for the description of the variables to be included in the data sets, the names, units and sign conventions proposed as well as the numerical format chosen for the files. To help the users to implement the data exchange format we furthermore provide a Frequently Asked Questions section and a list of examples of code which deals with the data exchange format.

This data exchange convention should not change the working habits of the groups participating in inter-comparisons. It should only provide a stable data exchange protocol around which working methods can be developed. It is thus important that these Web pages also serve as a forum for the exchange of expertise and software for the manipulation of data used to force and generated by land-surface schemes. This should be particularly useful for the groups who manage inter-comparison projects.

General comments on the data and meta data to be stored

The convention and its evolution

With each new land-surface scheme inter-comparison we learn how to exchange data in a more efficient way. In order to integrate this knowledge, the ALMA convention needs to evolve. We hope that the increments from one version to the other will become smaller and smaller over time and that finally the evolution will converge. In order to give a better overview of the changes, for each increment we will provide a log of the changes.

Version 3
(For use in PILPS-C1)
Change log
Version 2
(Used in Rhône-agg and GSWP-1.5)
Change log
Version 1
(Used in PILPS-2e)

Help and hints for using the convention

Laura Bowling and Jan Polcher

Last modified: Wed Mar 28 14:06:39 GMT 2001