4th International Conference on “Large-Scale Scientific Computations” (LSSC’03)

June, 4-8, 2003, Sozopol, Bulgaria

The conference, which was held in pictures town Sozopol, Bulgaria for the fourth time, was organized by the Central Laboratory for Parallel Processing (CLPP) of the Bulgarian Academy of Sciences, Sofia in cooperation with, University of Rousse, SIAM and GAMM. This conference has become a traditional event that takes place every second year, starting in 1997. During LSSC’03 conference a wide range of problems concerning recent achievements in the field of high performance methods and algorithms were presented and discussed. The meeting, which brought together numerical mathematicians, engineers, physicists, environmental and computer science specialists, etc., provided a forum for exchange of ideas between scientists, who develop and numerical methods and algorithms, and researchers, who apply them for solving real life problems.

Five Special Sessions were incorporated in the framework of LSSC’03 conference. Following the already established tradition, Adolf Ebel from the University of Cologne, Krassimir Georgiev from the Bulgarian Academy of Sciences and Zahari Zlatev from the National Environmental Research Institute of Denmark organized a special session on “Environmental Modelling”.

Roberto San Jose (Technical University of Madrid, Spain) presented and discussed some results of using a state-of-the-art 3rd generation air quality modelling system (MM5 - CMAQ) over a pilot test industrial site in Madrid mesoscale domain. The application has been done with CBM-IV chemical scheme. He concluded that MM5 – CMAQ modelling system can be used as an excellent tool for evaluating the impact of different emission sources in an operational mode.

Istvan Farago (Eotvos Lorand University, Budapest, Hungary) reported some new results about testing weighted splitting schemes on a one-column transport-chemistry model. He discussed some new splitting methods called weighted sequential splitting and weighted Strang splitting which have been recently developed. These splitting schemes are parallelizable on the operator level and have second order local splitting error. He concluded that the weighted splitting is more beneficial to apply than the traditional splitting.

Christelle Philippe (CORIA, Saint Etienne du Rouvray, France) discussed the use of the non-expensive clusters of PCs for atmospheric dispersion and pollutant chemical transformation simulation. Parallelization strategy that has been chosen is based on domain decomposition.

Marke Hongisto (Finnish Meteorological Institute, Helsinki, Finland) discussed the long-range transport of dust to the Baltic Sea region using hemispheric using results obtained by running the hemispheric dispersion model DMAT. The model was run through the period of over 20 years counting the dust storms episodes in northern Sahara and Caspian region and assessing whether these events affect Northern Europe.

Dimiter Syrakov (National Institute for Meteorology and Hydrology, Sofia, Bulgaria) presented some new results of studying the high ozone levels in Bulgaria and Europe using both coarse and fine resolution versions of the Danish Eulerian Model for long-range transport of air pollutants. He discussed how big is the influence of the European emission sources on the pollution levels in the different regions of Bulgaria and if it is possible to evaluate the changes of the pollution levels in Bulgaria and in Europe when the prescribed for 2010 European emission scenario is used.

Kostadin Ganev (Institute of Geophysics, Sofia, Bulgaria) presented a detailed study and explanation of the pollution transport in the air basin over SouthWestern and Northern Greece and assessment of the air pollution exchange between Bulgaria and Greece. He stressed on the extensive computer simulations, which were carried out. Three-layer pollution transport model with complex chemistry block was introduced and preliminary simulations of Sulfur and Nitrogen compounds transport were performed.

Tzvetan Ostromsky (Central Laboratory for Parallel Processing, Sofia, Bulgaria) reported about some performance results obtained using the parallel two-dimensional version of the Danish Eulerian Model for long-range transport of air pollutants. Results about speed up, parallel efficiency, computational speed and computational efficiency (performance obtained compared with the top performance of the corresponding computer architecture) were presented and discussed.

Krassimir Georgiev (Central Laboratory for Parallel Processing, Sofia, Bulgaria) presented a comparison of two local refinement methods for large-scale air pollution simulations. The numerical results obtained for the rotational and translational tests are discussed and some important conclusions for the implementation of this technique to the operational version of the Danish Eulerian model were done.