Papers by Ekaterina Batchvarova
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Anthem Press eBooks, Nov 20, 2018
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
The climate is an essential factor for human bio-comfort and health. Since ancient times, people ... more The climate is an essential factor for human bio-comfort and health. Since ancient times, people have used the climate's resources for their health, but at the same time, they have sought ways to cope with climate hazards. Nowadays, bioclimatic issues are gaining even greater importance, given the drastic increase in extreme climate events. There is a growing need for a deeper understanding of these events, the ways and mechanisms by which they affect the biostatus of the human organism, as well as the ways to deal with this problem at the individual and societal level. This report examines the main bioclimatic hazards in Bulgaria and their possible direct and indirect effects on human health. Direct are the effects of heat waves and ice episodes, intense precipitation and floods, strong winds, storms, avalanches, UV radiation overdoses, and contrasting weather changes. On the other hand, weather and climate indirectly affect our health through their influence on the air we breathe, the water we drink, the food we consume, and the ecosystems that surround us. The report also comments on some climate-sensitive diseases – respiratory, cardiovascular, and infectious (borne by water, food, air, and vectors). Socio-economic parameters of the society and of the individual have an important bearing on the intensity and number of these climate-related health consequences. Here they are considered as an index of health vulnerability in the country tracked for the period 1995-2020. On the other hand, this report also pays attention to the country's bioclimatic resources, with a view to using them to optimize human health. These are solar, thermal, air, wind, and cryogenic resources.The utilization of bioclimatic resources and dealing with bioclimatic hazards in Bulgaria are issues embedded in a number of state policies at the national and local level. This report sheds light on the main goals, priorities, and measures set out in the National Strategy for Adaptation to Climate Change. (Funding information: The study is supported by the National Science Fund of Bulgaria, Contract КП-06-ДК1/1).
We present an investigation of the structure of the aerosol layer at the Villum Research Station ... more We present an investigation of the structure of the aerosol layer at the Villum Research Station located at Station Nord in the high Arctic. Knowledge of the aerosol layering is of interest for the interpretation of measurements of atmospheric chemistry and particles that control air pollution in the pristine atmosphere and for climate change (Arctic amplification). Based on one year of remote sensing measurements by a ceilometer and a wind lidar, we discovered that the structure of the atmosphere was very different from what is usually found at mid-latitudes. Combining the ceilometer and wind lidar observations indicated that the aerosol layer has depths of about 100 m and 230 m and few cases of depth between 100 and 230 m. Studies of profiles with no aerosol-layer depth, based on high frequency ceilometer observations, reveal cases of entraining air. We found that the annual wind roses indicate generally westerly wind veering by more than 30 degrees between 40 and 200 m and a wind speed slowly increasing with height of about 5 m/s. It was found that the individual wind speed profiles between 40 and 200 m can roughly be categorized into 4 groups: 1. The wind speed increases from the ground up to 100m and thereafter decreasing (likely drainage); 2. The wind profile decreases from the ground up to a minimum at about 100 m; above this minimum the wind speed increases (no explanation for this type of wind profile is offered); 3. Wind speed increases with altitude; 4. Wind speed decreases from the ground throughout the whole layer. The two-layer structure of the aerosols and the different categories of wind profiles complicates the interpretation of surface observations. We discuss the implication in terms of local versus remote sources of aerosols and the uncertainty in backward trajectory modelling. These data can be used further for meteorological and aerosol model validation in the lower atmosphere of the High Arctic.Funding information: Danish Environmental Agency ‘Monitoring of short-lived climate components in Arctic’; European Cooperation in Science and Technology, Grant/Award Number: COST Action CA18235 PROBE; National Science Fund of Bulgaria, Grant/Award Number: KП-06-Н34/1; Nationalt Udvalg for Forskningsinfrastruktur (NUFI)
The marine Atmospheric Boundary Layer (ABL) over the southern Bulgarian Black Sea coast is studie... more The marine Atmospheric Boundary Layer (ABL) over the southern Bulgarian Black Sea coast is studied based on remote sensing measurements with a monostatic Doppler sodar system located at about 400 m inland. Long-term profile data (August 2008-October 2016) with high spatial (10 m) and temporal (20 min running averages at every 10 min) resolution was analysed to reveal the complex vertical structure of the coastal ABL at marine airflow. The processes of air masses transformation due to the sharp change in physical characteristics of the underlying surface lead to Internal Boundary Layer (IBL) formation. Its spatial scales as a sublayer of the coastal ABL depend on the distance from the shore. In the absence of temperature and humidity profile measurements, the turbulent profiles of marine air masses of different fetch over land (400 to 2500 m) were used to examine the characteristics of the IBL. Different fetch or distance passed by the marine airflow before reaching the sodar is considered selecting intervals of wind directions. IBL heights between 60 and 150 m depending on the fetch are obtained.
We report results from a multi-scale field experiment conducted in Cyprus in July 2010 in order t... more We report results from a multi-scale field experiment conducted in Cyprus in July 2010 in order to investigate the Urban Heat Island (UHI) in Nicosia capital city and its interaction with multiscal ...
EGU General Assembly Conference Abstracts, May 1, 2014
International Journal of Climatology, Feb 17, 2023
The depth of the aerosol layer at the Villum Research Station at Station Nord in the high Arctic ... more The depth of the aerosol layer at the Villum Research Station at Station Nord in the high Arctic is analysed based on 8 years of observations from a ceilometer and one full year from a wind lidar. The layer is of particular interest for aerosol process modelling and atmospheric chemistry studies. The depth of the aerosol layer is assigned to the inflection point in the attenuated backscatter profile by two methods; one is based on polynomial approximation of the profile and the other is direct numerical differentiation. The analysis is based on two types of hourly profiles; one consists of averaging the attenuated backscatter observations and the other by computing the median. Due to sporadic occurrence of outliers in the ranges around 50 m in the ceilometer observations, this part of the profile is not used in this study. Restricting the observations to heights above 100 m, the depths of the aerosol layer are found to be typically ≈230 m. It varies little between winter and summer, but the spread in the depth is larger during the winter as compared to summer. To extend the study of the aerosol‐layer depth below 100 m, a method is applied that combines the ceilometer measurements with the carrier‐to‐noise ratio from the wind lidar. The results are available for 2018 only, and they show aerosol‐layer depths below ≈80 m as well as depths around 230 m and they show few observations between ≈80 and ≈230 m. Near the ground, the observed backscatter exhibits a pronounced seasonal variation, having low values during the summer and high values during the winter. The strength of the seasonal variability decreases with height, especially above the aerosol‐layer depth, and is virtually absent at 1 km.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
DTU Orbit (10/11/2019) Dependence of Weibull distribution parameters on the CNR threshold i wind ... more DTU Orbit (10/11/2019) Dependence of Weibull distribution parameters on the CNR threshold i wind lidar data The increase in height and area swept by the blades of wind turbines that harvest energy from the air flow in the lower atmosphere have raised a need for better understanding of the structure of the profiles of the wind, its gusts and the monthly to annual long-term, statistical distribution in the boundary layer. Observations from tall towers in combination with observations from a lidar of wind speed up to 600 m are used to study the long-term variability of the wind profile over suburban, rural, coastal and marine areas. The variability is expressed in terms of the shape parameter in the Weibull distribution. When the lidar Carrier to Noise Ratio (CNR) is lower than a threshold value the observations are often not used as the uncertainty on the wind speed of the lidar measurements increases. This analysis shows that the mean wind speed is a function of the applied CNR threshold, which indicates a higher concentration of dust and aerosols driven by changes of near-surface wind speed. The height of the maximum in the profile of the shape parameter in the Weibull distribution (so-called reversal height) was found to depend on the applied CNR threshold; it is found to be lower at small CNR threshold values. Based on the measurements, a parametrization of the vertical profile of the shape parameter that consists of two terms is devised. Comparison with the observations reveals that the terms interplay in such a way that for heights typical for wind turbines (100 to 150 m) the first term is essential over land, both terms are about equally important in the coastal area where the height of the reversal height is low and in the marine conditions, the second term dominates.
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Papers by Ekaterina Batchvarova