ALADIN: The SHORT-TERM Numerical Weather Prediction

Project Genesis

Committed (in its objective) to experimenting and operating a limited-scale and high resolution model to develop its own forecasts, at a much finer spatial scale than is allowed by the global models currently used. The NIM joined ALADIN Consortium (Limited Area, Dynamic Adaptation, InterNational Development) in 2001. Launched in 1991 by Meteo-France, ALADIN is a project which aims at building mutual collaboration in the field of Numerical Weather Prediction (NWP) with the Meteorological Services of Eastern and Central Europe as well as Morocco and Algeria.

A hundred scientists from the fifteen partner countries have been contributing to an ALADIN PN system (more than 250 person-years of total work for the first ten years of the project's life) which is operating daily on a wide variety of platforms going from a PC Cluster under Linux to Vector high performance computers.

Objectives

• General

Establishing a Numerical Weather Prediction cycle at NIM

• Specific

Promoting Numerical Weather Prediction on a limited area centred on Tunisia, through the installation, maintenance and development of a version of the ALADIN model tailored to the geographical and climatological characteristics of Tunisia, with the aim of establishing a valuable forecast as a response to the needs of Tunisia's socio-economic practices.

ALADIN Partners

1991: The project was launched with only seven partners: Austria, Bulgaria, France, Hungary, Poland, Czech Republic, and Romania.

1993: Countries such as Morocco, Slovakia, and Slovenia joined ALADIN.

Then, in 1995, Croatia, in 1996, Belgium and Moldavia, in 1997, Portugal and 2001, Tunisia joined ALADIN.

• Zentralanstalt für Meteorologie und Geodynamik (Austria)
• The Bulgarian National Institute for Meteorology and Hydrology (Bulgaria)
• Météo-France (France)
• The Hungarian Meteorological Service (Hungary)
• The Institute of Meteorology and Water Management of Poland (Poland)
• Czech Hydrometeorological Institute (Czech Republic)
• The Romanian National Institute for Meteorology and Hydrology (Romania)
• The Directorate of National Meteorology (Morocco)
• The Slovak Hydrometeorological Institute (Slovakia)
• The Hydrometeorological Institute of Slovenia (Slovenia)
• The Croatian Meteorological and Hydrological Service (Croatia)
• The Royal Meteorological Institute (Belgium)
• Moldavian Hydrometeorological Service (Moldavia)
• Portuguese Meteorological Institute (Portugal)
• The National Institute of Meteorology (Tunisia)

Project duration

2 years for the implementation phase of the model (2001-2003).

Expected outcomes

• Preparing and maintaining a NP system to be used on the limited geographical area in Tunisia, with the possibility of zooming in with regard to the ARPEGE model of Meteo-France.
• Working on small-scale areas with a high spatial resolution.
• Implementing a top-level tool by participating in a genuine NP joint development, meant to be used by all the partners.

Ongoing actions

• A first pre-operational version of the ALADIN model, tailored to the Tunisia domain, was set up on Meteo-France computer in Toulouse, in September 2001. An extract from the provided fields is sent to Tunis daily via the Internet.
• This outputs from the ALADIN model is remotely used by the NIM forecasters and are subject to double evaluation.
• Some tools and interfaces have been developed by the Numerical Prediction team, allowing forecasters to familiarize with the model.
• An objective control procedure has also been set up for the major fields describing the sensitive weather.
• By the year 2002, the NIM invested in the purchase of a high-performance computer to run, locally, the "ALADIN-Tunisia" numerical prediction cycle.
• A scientific plan dealing with the various aspects of the ALADIN-Tunisia version was drafted during the period between 2002 and 2005. The topics have been defined, discussed and agreed upon as follows:
• • Assessment of convection schemes in semi-arid zone.
  • Study of relaxation of the thin layer hypothesis within the ALADIN dynamics.
  • Definition of surface characteristics for ALADIN.
  • Implementation of an observation monitoring system upstream from ALADIN.