Dimiter Syrakov

A fine-resolution modelling study of pollution levels in Bulgaria. Part 2: high ozone levels

Ozone pollution may cause damage to plants, animals and human beings when certain critical levels are exceeded. Therefore, it is important to study actual ozone levels and their relationship with the related emissions. Several secondary indices, directly related to the damages, are studied in this paper, rather than the proper ozone concentrations. Two versions (rough and fine grid ones) of the Danish Eulerian Model (DEM) are used in an attempt to answer the following three questions: where in Bulgaria and in Europe the highest ozone concentrations are located; how big is the influence of the European emission sources on the pollution levels in Bulgaria; and is it possible to evaluate the changes of the pollution levels in Bulgaria and in Europe when the European emissions predicted for 2010 are used? Three emission scenarios are run with meteorology for 1997: the Basic Scenario, where the 1997 EMEP emission inventory is used; the Bulgarian Scenario, where only Bulgarian emissions are set to zero; and Scenario 2010, where the 1990 EMEP inventory is modified by various factors. The results are presented by using many tables and plots, which demonstrate the relationships and the trends. Several conclusions are drawn and plans for future research are sketched.

A fine-resolution modelling study of pollution levels in Bulgaria. Part 1: SOx and NOx pollution

Two versions of the Danish Eulerian Model (DEM) with resolutions of 50 and 10 km on the Europe domain have been used to study: (i) where the highest SOx and NOx Bulgarian pollution levels are located; (ii) how great is the influence of European emission sources on the pollution levels in Bulgaria; and (iii) whether it is possible to evaluate the changes of the pollution levels in Bulgaria when the European emissions predicted for 2010 are used. Three scenarios were run (each of them run twice on both 50 and 10 km grids) in the attempt to answer these three questions: the Basic Scenario (obtained by using all European emissions for 1997); the Bulgarian Scenario (obtained by setting the Bulgarian emissions to zero) and Scenario 2010 (obtained by using the European emissions predicted for 2010). Meteorological data for 1997 were used and only the emissions were varied. The results are presented by using tables and plots, which demonstrate the trends and the relationships. Several conclusions are drawn and plans for future research are sketched.

Accounting for the mesoscale effects on the air pollution in some cases of large sulfur pollution in Bulgaria or Northern Greece

The objective of the present work is to demonstrate the influence of the meso-scale dynamic phenomena on the larger scale air pollution characteristics. A limited set of episodes with very large sulphur pollution in Bulgaria or Northern Greece is chosen for the study. A 3D quasi-hydrostatic model of the meso-scale dynamics, based on the Businesque approximation (the formulation of Guthman) is used for the purpose. Some numerical experiments for the Balkan Peninsula are carried out under different background (synoptic) conditions. The simulated flow systems outline the main topography effects, typical for the region, such as slope winds, channelling of the air flows or blocking effects. Numerical simulations of the air pollution transport are also carried out, with and without accounting for the meso-scale deformations of the wind field. The comparison of the air pollution characteristics, obtained in both the cases demonstrates that the underlying surface heterogeneity in some of the synoptic situations may have influence not only on the detailed air pollution field in the region, but also on some larger scale pollution characteristics – the total pollution quantity in the air above the countries, the mean surface concentration, the pollution fluxes trough the country boundaries, dry and wet deposition.

Exchange of sulfur pollution between Bulgaria and Greece

The EMAP model (Eulerian Model for Air Pollution) is applied for calculating the sulfur concentration and deposition fields for 1995 as based upon Bulgarian and Greek sources. The country-to-country budgets show that about 4% of the sulfur oxides emitted by Bulgaria are deposited over Greek territory, estimated at 28 kt S. Only 2% of sulfur compounds emitted by Greece are deposited over Bulgaria, estimated at 6.2 kt S for 1995. This data is in agreement with EMEP/MSC-W estimates and provides more details concerning time and space. The results can be used in decision-making, negotiating and the development of contamination strategies.

Grid computing for atmospheric composition studies in Bulgaria

Three Grid applications from the SEE-GRID-SCI Environmental VO are developed by the Bulgarian project team: Climate Change Impact on Air Quality (CCIAQ); Multi-scale atmospheric composition modeling (MSACM); Modeling System for Emergency Response to the Release of Harmful Substances in the Atmosphere (MSERRHSA). The three applications concern problems of significant socio-economic significance. They are all dedicated to air pollution studies, but address different goals and so face different problems and requirements. The applications are briefly presented in the paper. Examples of the different applications validations are given. Some application results are shown and commented.

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.

Simulation of European air quality by WRF-CMAQ models using AQMEII-2 infrastructure

The air quality modeling system WRF-CMAQ was applied to the European domain for the year 2010 in the frame of the Air Quality Model Evaluation International Initiative (AQMEII), Phase 2. The model system was set up for a domain of 5000×5000?km2 size with horizontal resolution of 25km. The emissions at European level were available through AQMEII and further processed in a way to feed the chemistry transport model CMAQ. The meso-meteorological model WRF was driven by NCEP GFS data with 1?×1? resolution. The chemical boundary conditions were extracted from MACC global simulation data. Model performance was investigated by means of AQMEII-2 web based evaluation platform and the monitoring data gathered for this activity. A preliminary model evaluation for ozone, nitrogen dioxide and particulate matter was conducted. The statistical analysis was based on comparison between simulated and observed concentrations at different type of surface stations in the EU wide domain (rural, urban, suburban), as well as for selected four cities. Model performance was characterized by overestimation for ozone and underestimation for the other pollutants. The relative statistical indicators were discussed also in view of recently published performance criteria. The model inter-comparison initiative AQMEII is outlined.The NIMHs WRF-CMAQ model system as designed for AQMEII-2 exercise is described.Simulations for 2010 over Europe as prepared for the ENSEMBLE tool are described.O3, NO2 and PM model results are analyzed against surface measurements in ENSEMBLE.

Study of the pollution exchange between Bulgaria and northern Greece

The present work aims at a detailed study and explanation of the pollution transport in the air basin over south-western Bulgaria and northern Greece and assessment of the air pollution exchange between Bulgaria and Greece. Some well-known specific climatic air pollution effects were studied and explained. Calculations were made of the SO2 pollution of the Balkan Peninsula from both Greek and Bulgarian sources for 1995, and the country-to-country pollution budget diagrams were built. Days with extreme mean concentration for Bulgaria and northern Greece were picked out, and some further specification of the contribution of the different sources in both the countries to these cases of extreme pollution was made. Some preliminary studies of possible mesoscale effects on the pollution exchange between Bulgaria and northern Greece were carried out. A three-layer pollution transport model with a more complex chemistry block was introduced, and some preliminary simulations of the transport of sulfur and nitrogen...

Climate change impact assessment of air pollution levels in bulgaria

The presented work is aiming at climate change impacts and vulnerability assessment in Bulgaria Climate change may affect exposures to air pollutants by affecting weather and thereby local and regional pollution concentrations Local weather patterns influence atmospheric chemical reactions and can also affect atmospheric transport and deposition processes. US EPA Models-3 System for a region with resolution of 10 km covering Bulgaria is exploited here The meteorological background is produced by the climatic version of ALADIN weather forecast system TNO emission inventory for 2000 is used The chemical boundary conditions are extracted from 50-km resolution runs over Europe made in Aristotle University of Thessaloniki, Greece Calculations for the period 1991-2000 are performed, results presented in a study For year 2000, some scenarios are run, results compared with measured data.

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.