Georgi Gadzhev

Contribution of biogenic emissions to the atmospheric composition of the Balkan Region and Bulgaria

The present work aims at studying the local to regional atmospheric pollution transport and transformation processes over the Balkan Peninsula and Bulgaria. The US EPA models-3 system is chosen as a modelling tool. As the NCEP global analysis data with one degree resolution is used as meteorological background, the models nesting capabilities are applied for downscaling the simulations to a 9 km resolution over Balkans and 3 km over Bulgaria. The TNO emission inventory is used as emission input. Special pre-processing procedures are created for introducing temporal profiles and speciation of the emissions. The study is based on a large number of numerical simulations carried out for two emission scenarios – with all the emissions and with biogenic emissions excluded. Some results from both emission scenarios which make it possible to evaluate the contribution of biogenic emissions are demonstrated in the paper.

Analysis of the Processes Which Form the Air Pollution Pattern over Bulgaria

The air pollution transport is subject to different scale phenomena, each characterized by specific atmospheric dynamics mechanisms, chemical transformations, typical time scales etc. The air pollution pattern is formed as a result of interaction of different processes. The present study attempts to make some evaluations of the contribution of different processes to the local to regional pollution over Bulgaria. The US EPA Model-3 system is chosen as a modelling tool. As the NCEP Global Analysis Data with one degree resolution is used as meteorological background, the MM5 and CMAQ nesting capabilities are applied for downscaling the simulations to a 3 km resolution over Bulgaria.

Multi-scale Atmospheric Composition Modelling for Bulgaria

The present work aims to studying the local to regional atmospheric pollution transport and transformation processes over Bulgaria and to tracking and characterizing the main pathways and processes that lead to atmospheric composition formation in the region. The US EPA Models-3 system is chosen as a modelling tool. As the NCEP Global Analysis Data with 1° resolution is used as meteorological background, the MM5 and CMAQ nesting capabilities are applied for downscaling the simulations to a 9 km resolution over Balkans and 3 km over Bulgaria. The TNO emission inventory is used as emission input. Special pre-processing procedures are created for introducing temporal profiles and speciation of the emissions. The study is based on a large number of numerical simulations carried out to four emission scenarios – with all the emissions and with excluded biogenic emissions, emissions from energetics and road transport. Some results from the numerical simulations concerning the main features of the atmospheric composition in Bulgaria and the contribution of the different emission categories are demonstrated in the paper.

Some Basic Facts About the Atmospheric Composition in Bulgaria – Grid Computing Simulations

The present work aims at studying the local to regional atmospheric pollution transport and transformation processes over Bulgaria and at tracking and characterizing the main pathways and processes that lead to atmospheric composition formation in the region.

Bulgarian Emergency Response System for Release of Hazardous Pollutants – Design and First Tests

The present paper demonstrates some preliminary results of the set up and testing of a system for modelling of toxic air pollution due to possible accidents in industrial sites. Risk assessment for the region of “Vereya Him” factory, Yambol, Bulgaria is performed. The modelling tools used for this study are: WRF, CMAQ and SMOKE. The CB05 toxic chemical mechanism, including chlorine reactions, is used. The shown numerical results demonstrate the practical value of the preparedness mode of the planned emergency response system.

Numerical study of some high PM10 level episodes

The study examines the ability of US EPA Models-3 system to reproduce air pollution episodes and to evaluate the role of different processes in the PM10 pattern formation. The case study focuses on three major PM10 episodes, that occurred over Germany in February and March of 2003. The emission input is prepared on the basis of the TNO inventory. The simulated PM10 concentrations are compared with measurements from the EMEP stations in Germany. The Integrated Process Rate Analysis function of CMAQ is applied for clarifying the role of different processes in forming PM10 concentration peaks.

Joint analysis of regional scale transport and transformation of air pollution from road and ship transport

The objective of the present work is to study in detail the dilution processes of the plumes and the chemical transformations of pollutants jointly generated by road and ship transport. The numerical simulations are carried out using the MODELS-3 system (SMOKE/ MM5/CMAQ) nesting abilities, downscaling to a horizontal resolution of 30 km, the innermost domain including regions with very intensive road and ship transport and different climate (photochemistry reactions intensity) The CMAQ “Process rate analysis” option is applied to discriminate the role of different dynamic and chemical processes to the pollution levels formation. A large number of numerical experiments were carried out, which makes it possible to distinguish the relative contribution of different air pollution factors Careful and detailed analysis of the obtained results was made, outlining the influence of the domain specific physiographic characteristics, road and ship emission impacts on the pollution characteristics.

TVRegCM Numerical Simulations - Preliminary Results

The oncoming climate changes at the moment are the biggest challenge the mankind is faced with. They will exert influence on the ecosystems, on the all branches of the national economy, and on the quality of life. The climate changes and their consequences have a great number of regional features, which the global models cannot predict. That is why an operation plan for adaptation to climate changes has to be based on scientifically well-grounded assessments, giving an account of regional features in the climate changes and their consequences.

Computer Simulations of Atmospheric Composition in Urban Areas. Some Results for the City of Sofia

Some extensive numerical simulations of the atmospheric composition fields in the city of Sofia have been recently performed. An ensemble, comprehensive enough as to provide statistically reliable assessment of the atmospheric composition climate of Sofia—typical and extreme features of the special/temporal behavior, annual means and seasonal variations, etc. has been constructed. The simulations were carried out using the American Environment Protection Agency (US EPA) Models-3 system. As the National Centers for Environmental Prediction (NCEP) Global Analysis Data with 1 degree resolution was used as meteorological background, the system nesting capabilities were applied for downscaling the simulations to a 1 km resolution over Sofia. The national emission inventory was used as an emission input for Bulgaria, while outside the country the emissions were taken from the Netherlands Organization for Applied Scientific research (TNO) inventory. Special pre-processing procedures are created for introducing temporal profiles and speciation of the emissions. The biogenic emissions of Volatile Organic Compound (VOC) are estimated by the model Sparse Matrix Operator Kernel Emissions (SMOKE). The air pollution pattern is formed as a result of interaction of different processes, so knowing the contribution of each for different meteorological conditions and given emission spatial configuration and temporal behavior could be interesting. Different characteristics of the numerically obtained concentration fields of pollutants as well as of determining the contribution of different types of pollutants and pollution sources will be demonstrated in the present paper.

Sensitivity Study of Different RegCM4.4 Model Set-Ups – Recent Results from the TVRegCM Experiment

Abstract The oncoming climate changes will exert influence on the ecosystems, on all branches of the international economy, and on the quality of life. Global Circulation Models (GCMs) are the most widespread and successful tools employed for both numerical weather forecast and climate research since the 1980s. However, growing demands on accurate and reliable information on regional and sub-regional scale are not directly met by relatively coarse resolution global models, mainly due to the excessive costs affiliated with the use of the model in very high resolution. Regional Climate Models (RCMs) are important instruments used for downscaling climate simulations from GCMs. Main aim of the numerical experiment Tuning an Validation of Regional Climate Model (RegCM-TVRegCM) is to quantify the impact of some tunable factors in the RegCM set-up on the model outputs. Thus, on the first stage of the study, the skill of 20 different model configurations in representing the basic spatial and temporal patterns of the Southeast European (SE) climate for the period 1999-2009, is evaluated. Based on these outcomes, the present work is dedicated on more detailed inspection of the model set-ups with recognizable better performance. The Pearson’s correlation coefficient between the time series of the temperature and precipitation of the 6 most promising model set-ups and the E-OBS on monthly basis are calculated. The main conclusion is that this test does not reveal single one model set-up that definitely over performs the other considered ones.