LAM Aladin

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The abbreviation ALADIN stands for French A ire L imitée A daptation dynamique D éveloppement I nter N ational , a LAM - weather model ( Limited Area Forecasting , ALADIN-LAEF), which was used especially in western, central and south-eastern Europe and North Africa. Meanwhile, the model was largely determined by the developments and ALARO AROME ( A pplication of R esearch to O pera tion at Me replaced soscale) with improved model physics packages especially for high resolutions. Furthermore, there is the ALADIN consortium , the organizational association of the countries operating the ALADIN, ALARO and AROME models. Variants of the models are now also operated in Scandinavia, Ireland and Spain under the name HARMONIE.

Project goal and international cooperation

The idea of ​​the ALADIN weather model was proposed by Météo-France in 1990 and implemented in cooperation with several weather services in Central and Eastern Europe. This cooperation should take place within the framework of numerical weather forecast  (NWP), the basis of modern meteorology.

Project goals The goal of the development of ALADIN was the best possible forecast of the weather development in the short and medium term range (up to +72 h) taking into account regional effects.

Currently, more than one hundred scientists from more than 16 countries who have participated in this project are working on the ongoing weather development of the ALADIN / ALARO / AROME weather model. The ALADIN system is used operationally today in 16 countries in Europe and in the Mediterranean area for the preparation of weather forecasts . Added to this are the operational HARMONY runs in the countries of the HIRLAM consortium as well as the numerical predictions operated by Météo-France in the overseas territories (DOM-TOMs), e.g. B. ALADIN-Réunion.

Development and application

Due to the lower spatial and temporal resolutions of the global ECMWF model for Europe, regional phenomena such as B. topographical increase in precipitation is not recorded satisfactorily. For this reason, a different, more specialized calculation model was sought, particularly in the Alpine countries.

The aim of the project was to set up an NWP system that met the highest international standards from the outset, in which all partners effectively participate and in the end use the joint result. Since the weather model is currently used by 14 different countries in Europe, some slightly different resolutions are used, and on the other hand, since the start of the project, all model excerpts in Europe have been adapted to specific regions in order to further improve the regional forecasts.

The model domain ALADIN-AUSTRIA, which was introduced into operational operation at the Central Institute for Meteorology and Geodynamics in 1998 and which included the calculations for Central and Eastern Europe, had a horizontal resolution of 9.6 km and 45 layers in the vertical. At the moment, all parameters of a 4.8 km 60 shift ALARO version are available in the hour segment for a period of 72 hours. With the model input, the main meteorological dates, the calculations are available a total of four times a day, recalculated.

LAMEPS ( Limited Area Model Ensemble Prediction Systems ) have continued to grow as a scientific tool to improve the predictions of high impact weather, especially when it comes to short-term mesoscale probability prediction.

Model properties

The execution and maintenance of an NWP system for limited geographical areas ( Limited Area Model , LAM) only requires reduced computing skills, but allows a magnifying glass effect compared to the global models ECMWF-IFS / ARPEGE . The method is based on work in the sense of small model areas and high meshes: It is assumed that the essential meteorological elements on a fine atmospheric scale - local winds, breezes, thunderstorm lines and the like - predominantly come from the dynamic adaptation of the air flows to the earth's surface.

There is a need for development, especially with regard to the forecast of showers and thunderstorm cells, as well as the forecast of deep cloud cover ( inversion clouds , high fog ). The medium-term goal is also to process additional observations in the calculation of the initial condition (assimilation), especially in the Alpine region.

The alpine convection is mostly somewhat overestimated, especially on many days, which is due on the one hand to the limited resolution of the topography and on the other hand to the simplified simulation (parameterization) of the convective cloud development in the model. As in other forecast models, the time at which convective precipitation will start is often forecast too early in the course of the day.

Web links

Individual evidence

  1. ↑ DANE de l'académie de Lyon: ALADIN. In: www.umr-cnrm.fr. Retrieved December 19, 2016 .
  2. ↑ HARMONIE documentation (English)
  3. ↑ Operational Model , on www.meteo.fr
  4. ↑ a b [ZAMG Research - Aladin]. ( Memento from May 16, 2012 in the Internet Archive ), on zamg.ac.at
  5. ↑ Karin Schmeisser: Evaluation of the added value of LAMEPS in contrast to global EPS. Diploma thesis, University of Vienna, 2012 ( abstract and link to pdf , othes.univie.ac.at).