Foreword NEWSLETTER, March 2011

A few months ago, the ALADIN programme reached the venerable age of 20 years. Its legacy today is quite remarkable, not to say impressive. There are now sixteen countries, each with its own specificity in resources and knowledge base. But we are working together on a modern code of the atmosphere that definitely deserves its proper place between the European state-of-the-art NWP models.

The atmospheric sciences are burdened with complexity. Think of the intrinsic non linearity, the number of involved physical processes and the amount of assimilated data. On top of that we need heavy engineering efforts to make the model up and running and, more importantly, to maintain the system. Given this complexity, it is a historical surprise that numerical weather prediction is anyhow possible, and that its quality continues to improve. Personally I think that, too often, we do not realize this well enough. The crucial drivers that made all of this possible are, without a doubt, the accumulation of scientific knowledge and technical expertise, and a well controlled maintenance system.

At the same time, we now expect some serious evolutions within the NWP landscape in the coming five to ten years. There is the ever-lasting question where to draw the line between resolved vs. parameterized processes. There is the question of the efficiency and the scalability of our dynamical core. There are the external drivers, such as the demands of the end users, and the evolution of the high-performance computing machines. Additionally a serious reorganization of the code is now at hand, in particular within the OOPS project. Besides that, the international meteorological context is steadily changing, specifically in our case, with the merger of the ALADIN and the HIRLAM consortia.

Within our consortium, we had a number of unique successes in the past. For instance, we succeeded to plug in an existing physics parameterization in our existing code, leading the AROME model. We are at the forefront of the gray-zone problematics with the ALARO physics. And we have a remarkably stable dynamical core.

ALADIN as a model, as an international consortium and as a research and development programme, came into existence and acquired its present shape due to the truly exceptional efforts of my predecessor, Jean-François Geleyn. On December 15^th, last year the management of the consortium was given over to me. I consider this a great honor. It is now my job to reassure the past legacy, while at the same time facing the challenges of the future. I will do my very best.

Piet Termonia

ALADIN Program Manager