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Study of One Month High Polluted Pm Event for Sofia Region

Author(s): Margret Velizarova / Language(s): English Publication Year: 0

The habitants in Bulgarian capital city are unfortunately still exposed to high levels of particulate matter (PM) despite a lot of efforts made by the government and municipality during the last decades. A high resolution modelling using ADMS-Urban system was carried out for prolonged one month (January 2014) event with elevated levels of PM concentration for Sofia region. Four main emission sources (point industrial, domestic heating, roads and non-well defined transport) were taken into account for this study. Although this type of modelling accounts only for the local sources and has some deficiency, it can be very useful tool for estimation of the contribution of each source type to the concentration field and also allows to simulate different scenarios for future emission reduction that can help the authorities in decision making.

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Satellite Data Assimilation of Air Quality Parameters in Bulgaria

Author(s): Dimiter Syrakov,Maria Prodanova,Emilia Georgieva / Language(s): English Publication Year: 0

he operational Bulgarian Chemical Weather Forecast System (BgCWFS) was modified and applied for assimilation of satellite retrieved atmospheric chemistry parameters - Aerosol Optical Depth (AOD) and columnar values of NO2 and SO2. The work outlines the methodology based on calculation of correction factors between model estimated and satellite derived parameters. Two model simulations for August 2017 and February 2019 are made – Model Run (without satellite data assimilation – mod-run) and Satellite Run (with satellite data assimilation – sat-run) for all 5 domains of BgCWFS. In the paper the effect of the assimilation is demonstrated stressing mainly on the difference between sat- and mod-runs. The comparison of sat-run results with observations and with third party modelling results are object of other publications.

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Preliminary Results for the Recurrence of Air Quality Index for the City of Sofia from 2008 to 2019

Author(s): Georgi Gadzhev / Language(s): English Publication Year: 0

The living environment of human beings and, obviously, the atmospheric composition has a great impact for the quality of life and human health. Air Quality (AQ) is a key element of European citizens' wellbeing and quality of life. The objectives of the present work are to conduct reliable, comprehensive and detailed studies of the impact of lower atmosphere composition on the quality of life and health risks for the population in the city of Sofia. The performed numerical simulations with the US EPA Models-3 system are for 12 years from 2008-2019 and calculated on five domains: Europe, Balkan Peninsula, Bulgaria, Sofia Municipality and Sofia City with increasing space resolution - from 81 km (Europe) to 1 km (Sofia City). The System is based on the well-known models WRF (Meso-Meteorological Model) and US EPA dispersion model CMAQ (Chemical Transport Model). As emission input the TNO data is used for the two biggest domains. For the 3 Bulgarian domains the current emission inventory prepared by Bulgarian environmental authorities is exploited.

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Particulate Matter Characteristics and Atmospheric Boundary Layer Height over Sofia

Author(s): Plamen Savov,Nikolay Kolev,Ekaterina Batchvarova,Hristina Kirova,Maria Kolarova / Language(s): English Publication Year: 0

The paper presents results from aerosol experimental campaigns performed in the urban environment of Sofia. Laser Particle Counter (PLC) data of 2 summer days (June, 7 and 8) and 4 winter days (December, 18, 19, 20, 21) of 2019 are discussed. Aerosol particle concentrations (number/l and mass µg/m3) in channels 0-2.5 µm and 2.5-10 µm are measured at the open green area near Pliska (at 30 m distance from boulevard Tsarigradsko shose). The combined effect of the daily development of atmospheric boundary layer height, meteorological parameters, and hourly variations in the concentrations of the aerosol fractions is discussed. WRF-GDAS and HYSPLIT models are used for determination of the atmospheric boundary layer height and to follow the transport of air masses. BSC-DREAM dust model is used as an additional source of information to assess the long-range intrusion of dust.

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How Well Do the Air Quality Models EMEP and CAMS Reproduce Particulate Matter Surface Concentrations in Bulgaria

Author(s): Hristina Kirova,Nadya Neykova,Emilia Georgieva / Language(s): English Publication Year: 0

The main objective of this study is to evaluate the performance of some well-known and widely used operational air quality modelling systems (EMEP-MSC-W, and the models at the Copernicus Atmosphere Monitoring Service (CAMS)) for simulations of particulate matter in Bulgaria. The analysis is focussed on a summer month (August 2017) and includes comparison of model to observations from 24 regular air quality background stations, as well as model inter-comparison. Along with statistical indicators various graphs are used - box plots, kernel density estimations,and scatter plots. The spatial distribution is discussed upon maps of monthly mean concentrations and comparison of domain averaged model concentrations. The spatial distribution of PM10 is similar only over the Black sea. The highest domain mean surface concentrations are simulated by CAMS global – by about 12 % for PM10 and by about 14 % for PM2.5 higher than the other models.

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Black Sea Freezing and Winter Severity: Relation to the Temperature

Author(s): Mirna Matov,Elisaveta Peneva,Greta Georgieva / Language(s): English Publication Year: 0

Black Sea freezing is observed regularly in the northern part and near the Kerch Strait. The reason is the relatively shallow northwestern shelf part and the river inflow of the three major European rivers Danube, Dniepr and Dniestr, carrying large amount of fresh water to this part of the Black Sea. The observed global warming in the latest decades makes these episodes less intense. In 2012 and 2017 the sea ice extended unusually south. The aim of this study is to fill the gap of recent analysis on the Northern Black Sea areas covered regularly with ice. Based on the coastal meteorological stations measurements, we investigate the interannual-to-decadal variability of the thermal regime.The relation with the sea-ice cover based on satellite observations is studied. We define various categories of winter conditions depending on the number of cold days.

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Assessment of the Future Climate over Southeast Europe Based on CMIP5 Ensemble of Climate Indices – Part One: Concept and Methods

Author(s): Hristo Chervenkov,Vladimir Ivanov,Georgi Gadzhev,Kostadin Ganev / Language(s): English Publication Year: 0

Nowadays there is a strong degree of agreement that the climate change is the defining challenge of our time. The analysis based on climate indices is probably the most widely used non-parametric approach for quantification of extreme climate events. This study which consist of two parts, is dedicated on the assessment of the spatial patterns and the temporal evolution of 6 temperature-based and 3-precipitation based indices in projected future climate over south-east Europe up to the end of the century. The annual means of the daily mean and extreme temperatures are also analysed in consistent manner. The indices are computed from the bias-corrected output of 5 CMIP5 global models, forced with all 4 RCP emission scenarios. The multi model ensemble medians of the temperature-based indices shows considerable warming which is consistent with the increase of the mean temperatures and is statistically significant in most cases. The revealed changes of the precipitation-based indices are more complex when compared with temperature changes.

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Assessment of the Future Climate over Southeast Europe Based on CMIP5 Ensemble of Climate Indices – Part Two: Results and Discussion

Author(s): Hristo Chervenkov,Vladimir Ivanov,Georgi Gadzhev,Kostadin Ganev / Language(s): English Publication Year: 0

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Application of Backward Trajectories and Cluster Analysеs for Study of Variations in PM10 Concentrations

Author(s): Rozeta Neykova,Elena Hristova / Language(s): English Publication Year: 0

This study is on estimation of the influence of the air mass origin on particulate matter (PM10) levels in the city of Plovdiv, Bulgaria during 2019. The HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) and the statistical software package “Openair” in R are applied. The cluster analysis statistical method is used to group the back-trajectories into 5 sets according to the angle, direction and speed of the air mass. The Potential Source Contribution Function (PSCF) and Concentration Weighted Trajectory (CWT) statistical methods are also applied in order to identify source areas of pollutants. The PM10 concentrations in two air quality stations in Plovdiv and some meteorological elements are also presented and discussed. The influence of the clusters on PM10 levels is explained.

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Nocturnal Boundary-Layer Characteristic in a Costal Site Using Long-Term Sodar Data

Author(s): Damyan Barantiev,Ekaterina Batchvarova / Language(s): English Publication Year: 0

The coastal Atmospheric Boundary Layer (ABL) structure is subject of research in many countries as large number of cities and industrial activities are located onshore seas, oceans or lakes. Mean characteristics of ABL at a Bulgarian Black Sea coastal site are obtained based on unique long-term (August 2008 - October 2016) acoustic remote sensing measurements. Marine and land nocturnal air flow vertical profiles are studied. Exploring data of wind and turbulence profiles with high spatial (10 m) and temporal (10 min) resolution from SCINTEC MFAS sodar revealed typical parameters as the height of the Internal Boundary Layer (IBL), nocturnal ABL height over sea and land, etc. The seasonal variability of coastal ABL characteristics is explored. The reported results can be used for verification of theoretical, mesoscale and air quality models. The study contributes to the understanding of wind regime and turbulent structure of ABL in a region with modest observation networks and data near the surface and no measurements and data in vertical direction.

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Environmental Impact of Quarry Activities: the Case Study of a Gneiss Deposit in the Region of Blagoevgrad

Author(s): Radostina Angelova,Rositsa Velichkova,Sylvia Alexandrova / Language(s): English Publication Year: 0

The extraction of rock materials from the landscape is accompanied by severe influence on the nature. The research presents the assessment of the impact of the quarry activities in a gneiss deposit in the region of Blagoevgrad on the environment. The effect of the blasting operations and other quarry works are discussed in terms of the geomorphic impact, air and water pollution, noise, and influence on biota. Some measures for improvement of the quarry works and further quarry reclamation are suggested.

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Peniophora Proxima (Peniophoraceae, Basidiomycota): Newly Recorded for the Bulgarian Mycota

Author(s): Aneta Lambevska-Hristova,Svetlana Bancheva / Language(s): English Publication Year: 0

Peniophora proxima Bres. is corticioid fungus belonging to family Peniophoraceae (Basidiomycota). It is easily distinguished by the numerous encrusted cystidia, gloeocystidia and ellipsoid spores. The species is considered a common white rot saprobe restricted only to the Buxus representatives. One of the most popular species of the Old world is Buxus sempervirens L. (European boxwood), native to western and southern Europe, northwest Africa, and southwest Asia. Although the species does not belong to the native flora of Bulgaria, for many years, the European boxwoods have been one of the most popular and widely used landscaping plants, in the form of ornamental shrubs or dense, evergreen hedges in shady places. P. proxima has been reported from different parts of Europe, but it has not been previously reported for Bulgaria. This article reports this new find from three localities in Bulgaria, while providing information about the morphological and ecological features of the species and commenting on the pattern of its distribution.

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Methodology for Calculating the Parameters of Radio Paths with Ionospheric Reflection

Author(s): Plamen Mukhtarov,Rumiana Bojilova / Language(s): English Publication Year: 0

A methodology for calculating the parameters of radio paths operating with ionospheric reflection that depends on the state of the ionosphere and at a given distance of radio communication is presented. Based on the critical frequencies of the ionospheric regions E (foE) and F (foF2) and the maximum usable frequency at a distance of 3000 km (MUF3000), the electron density profile is reconstructed and the geometry of the radio wave reflection from the ionosphere is determined. As a result of the modeling, the frequency range of the radio waves at which radio communication is possible is determined; the latter is limited by the lowest usable frequency (LUF) and the highest usable frequency (MUF) illustrated by an example.

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GIS in Crises Management Use of Smart Phone GIS Application in the Event of Natural Disaster

Author(s): Aleksandar Petrovski,Nenad Taneski,Jugoslav Ackoski / Language(s): English Publication Year: 0

Today it has become both the government and citizens concern to care human beings against ever-increasing crisis around the globe. There are so many natural disasters like: forest fire incidents, earthquakes, floods, eruptions, tsunami and etc. despite all this kinds of natural and man- made disasters from a social perspective, it their potentiality to seriously and irreversible damage regions. In addition the extent and severity of such incidents may significantly affect the population. For that reason and the fact that Geographic information system is recognized as a useful system for alleviation the risk during the crisis management we develop the idea to promote a new model to have a practical and applicable method of GIS adoption within the crisis management in order to save as many lives as it can be done. This study aims to come out with a model that will not allow drop links. Each smart phone will have application in the event of natural disaster and it switched due to the change of the vital function of man in trouble. This will help departments respond as soon as they can and save lives as many as they can and to reduce the percentage of people who could not call for help. This work highlights the design challenges and required technical innovations towards the goal of making GIS much more useful.

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Framework for Wildfire Danger Prediction System

Author(s): Nina Dobrinkova,Maria Asenova / Language(s): English Publication Year: 0

Wildland fires are natural hazard that occur every year in different parts of the world. European Mediterranean countries often are suffering from this disaster and in some cases human casualties plus infrastructure damages are in place. Bulgaria as part of the north east Mediterranean basin is affected by wildland fires in the last three decades more often than before. In our article we will present a framework for wildfire danger prediction system by usage of wireless sensor networks collecting real data and elaborating it into alerts. The test area is located on the territory of South-West state-owned forestry district. The described approach is based on the national fire danger rating algorithm, but in our case downscaled to daily prognosis. The system is under construction at the time of the paper writing thus the framework of the system main functionalities is the main scope of the article.

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Evaluation of Sentinel-3a OLCI Ocean Color Products in the Western Black Sea

Author(s): Violeta Slabakova,Natalyia Slabakova,Snejana Moncheva,Nina Dzhembekova / Language(s): English Publication Year: 0

Ocean color remote sensing has entered a new era with the successful launch of the Ocean and Land Colour Instrument (OLCI) on board Copernicus Sentinel-3 satellites. The representativeness and accuracy of the OLCI geophysical products are poorly quantified in the Black Sea which is featured by high bio-optical complexity. This paper addresses the evaluation of the OLCI/3A sensor's performance for retrieving ocean color products of the western Black Sea waters, by carrying out qualitative and quantitative match-up analysis between in situ and OLCI data. Results indicate a systematic underestimate of the water-leaving radiances (more pronounced at 412 and 665 nm) in contrary to the OLCI standard Chlorophyll (CHL) products which significantly overestimate the in situ records. These findings confirm the need of consistent reference in situ bio-optical data with improved spatial and temporal coverage for further satellite ocean color missions calibration and validation activities in the Black Sea.

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A Modelling System for Numerical Weather Prediction in the Bulgarian Antarctic Base Area

Author(s): Boriana Chtirkova,Elisaveta Peneva,Gergana Georgieva / Language(s): English Publication Year: 0

The weather forecast of good quality is essential for the humans living and operating in the Bulgarian Antarctic Base (BAB), located on the Livingstone Island coast at 62.64⁰ S and 60.36⁰ W. The numerical weather prediction models in southern high latitude regions still need improvement as the user community is limited, little test cases are documented and validation data are scarce. The modelling system is based on the WRF model, configured in three nested domains down to 1 km horizontal resolution, centered over BAB. The main objective of the study is to configure and validate the WRF model and to recommend certain set-up parameters like model area coverage, topography, land use, vertical levels, physics parametrization schemes, preparation of initial and boundary conditions and run configuration on HPC machines. Three test periods of “bad” weather events are considered during the summer seasons in 2016, 2017 and 2020. The ability of the 3 days forecast to capture the basic meteorological events in this period is discussed. Sensitivity experiments to the land use type are conducted and while the MODIS land data is found to be the most accurate for the region, a slight increase in the soil thermal capacity results in better model performance.

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The Western Black Sea Waves 1980-2020 – Study Based on ERA5

Author(s): Vasko Galabov / Language(s): English Publication Year: 0

The study presents a reconstruction of the Western Black Sea wave climate based on a numerical hindcast using the SWAN wave model and ERA5 input data. While there are many wave hindcasts reconstructing the Black Sea wave climate, based on various atmospheric reanalysis projects, the present work is the first based on the state of art ERA5 reanalysis. We focus on the storminess affecting the Bulgarian coast. The storminess in the recent decade (2010-2019) was found to be the highest compared to the previous 3 decades covered by the reanalysis (while the previous 2000-2009 is with the lowest), but the trends in the storm proxies used in the study are not statistically significant. This confirms the conclusions of other studies that the wave climate of the Western Black Sea is steady.

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Storm Surges Affecting the Bulgarian Coast – Study Based on 41 Years Numerical Hindcast

Author(s): Vasko Galabov / Language(s): English Publication Year: 0

We present the results of the numerical hindcast of the storm surges affecting the Bulgarian Black Sea coast during the period 1979-2020, using atmospheric data from the ERA5 reanalysis. The aim of the study is to evaluate the changes in the surge intensity and frequency during the period. The highest identified surges in the hindcast output are the surges of February 1979, January 1981 and February 2012- the surge of 2012 is the highest, while the surge of 1979 was found to be the longest and the most energetic event. We found no statistically significant inter annual change in the number, total duration and the introduced index characterizing the total energy of the surges above 60cm or 80cm was found. The total annual number of events above 40cm is with increasing trend which is statistically significant, but the total duration of events above 40cm does not show statistically significant trend- we observe more frequent but shorter events in the range 40-60cm during the last decade.

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Seismological Analysis of the 2006 Kardzhali Earthquake

Author(s): Plamena Raykova,Dimcho Solakov,Stela Simeonova / Language(s): English Publication Year: 0

Studying of the space-time distribution of earthquakes is very important for understanding the physics of the earthquake generation process. The 2006 MW4.7 KARDZHALI earthquake was followed by an intensive aftershock activity. We analyze the space-temporal pattern of earthquake distribution in the aftershock sequence of the main event. We find that both space and temporal distribution of aftershocks shows non-random features. In this study P- and S-wave spectra for earthquakes from the seismic cluster (main earthquake - aftershocks) are generated. Earthquake parameters: seismic moment, source radius, stress drop are estimated applying Brune model for the MW4.7 quake and five aftershocks with magnitude МW in the interval 3.3 ÷ 3.7. The estimated stress drop value for the main event is within the expected range for moderate earthquakes (43 bars for the P-wave and approximately 65 bars for the S – wave).

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