| Abstract [eng] |
The main purpose of this diploma thesis “Particulate matter transport in the atmosphere research using SILAM model” (written by Adomas Mažeikis) is to use SILAM model to research the transport of local Particulate matter pollutants and those from neighboring countries too. Emission data was prepared by interpolating EMEP and Statistical Department provided data sets. Meteorological data was taken from Lithuanian HydroMeteorological Service HIRLAM installation. The setup of model was prepared and test runs were made (one of them is simulating fire in oil refinery "Mažeikių nafta"). The results of this thesis are large arrays of past (2007 October - 2008 April) PM10 dispersion data. Grads package was used to perform the analysis of data and these are the conclusions made after the analysis was finished: 1. SILAM model is accurate enough for researching country wide PM10 transport analysis. 2. Each and every model run needs individual setup for best performance. 3. SILAM is not user friendly application and there is a lack of documentation (User guide, Operational instructions and model technical descriptions are available but it does not describe the setup of model in details). 4. Users of SILAM should check model run logs. There is plenty of useful data in there though the format is not very usable. 5. Performed analysis of model run results shows that the biggest part of PM10 aerosol is in the lower levels of the troposphere and that part is transported up to 100km (this can only mean that the bigger parts of aerosol are in the lower layers and the tiny ones reach higher levels so they are transported much further). 6. After performing the analysis of model results, it is obvious that the main transport of PM10 from Lithuanian emission sources goes North North East (to Latvia) 7. Model results show that a lot of PM10 comes from neighbor country Poland (there are quite high emission levels from coal pools and metallurgical plants). 8. The biggest part of PM10 from Poland reaches only Southwest part of Lithuania, but the pollutants from the higher levels can be transported practically to all country. 9. Maximal concentration levels of PM10 in the atmosphere level up to 25 meters are up to 10 times higher than the average levels, but it is still just the half of maximal concentration when the PM10 is transported from Poland. 10. Main part of PM10 emitted by lithuanian sources is not transported to other countries. It falls out in the ways of wet and dry deposition. Moreover, bigger part of pollutants that come from Poland falls out in Lithuania too. 11. While analyzing the results of model, some specific situations were observed. All of them can be classified using three main classes of situations: PM10 concentration is very low over all Lithuania (because of meteorological conditions); the concentration of PM10 can rise sharply in some areas up to 10 times because of meteorological conditions (though the emission rate stays the same); if the meteorological conditions allow the bigger part (even bigger than the local one) pollutants can be transported from neighboring countries (especially Poland). The recommendations for scientists who are going to use SILAM is to evaluate the time needed for the tasks. Everything goes very well (the data formats ar specific but easy to understand, the setup can be arranged after making some mistakes), but using SILAM takes a lot of time. Because of the long time needed for calculations the main risk is that just before ending the model run it can crash and everything is needs to be started from the begining. |
