Marko Kaasik

• Ph.D.
• University of Tartu

Shelterwood cutting (SC) has been highlighted as an alternative method to clear-cut (CC)-based even-aged forest management. However, compared to CC, the effect of SC on stand carbon (C) balance is still poorly understood at the ecosystem level. We examined the prompt effect of SC versus CC on ecosystem net primary production (NEP) on a short-term s...

Environmental pollution is one of the most important problems in urban environment. Mosses are good indicatorsof air pollution. In Estonia, heavy metals have been measured from Pleurozium schreberi and Hylocomium splendens, whichdo not grow in areas of Tallinn with a higher pollution load. In the present study, Cu, Fe and Cd were measured from five...

Snow sampling, either by inserting a tube through the entire snowpack or by taking samples from the vertical profile, is widely applied to measure the snow depth, density, and snow water equivalent (SWE). A comparative study of snow-sampling methods was carried out on 24 March 2022 in Sodankylä, Finland. Six groups from five countries (Estonia, Fin...

In Europe, emissions of many air pollutants have decreased in recent decades, but there exist sites where concentrations of pollutants are still high and have become a public health problem. The air quality monitoring networks include urban stations in big cities and rural background stations. Main pollutants (SO2, NOx, CO, particulate matter) are...

The SILAM model was tested against the measurements of ground-based monitoring stations, when the peaks of SO2 and NO2 concentrations from tall industrial stacks occurred in cold anticyclonal weather with frequent ground-based thermal inversions. It was found that along with adequacy in terms of meso-scale transport, the ground-based inversions, hi...

The factors that determine the concentrations of air pollutants (NO, NO2, SO2, O3), measured in 8 monitoring stations (4 rural background, 3 urban, and 1 industrial) in Estonia, are studied applying the factor analysis. The factor analysis reveals remarkable impact of COVID-19 lockdown, effects caused by dramatic decrease in oil-shale based energy...

Considering the recent growth of interest in using mosses in creating vegetated green roofs, we set the aim of our study to get an overview of the variety of moss and liverwort species and communities growing spontaneously on roofs. Data were collected from 67 roofs of five different types of materials: fibre cement, bitumen, stone, thatched and st...

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and r...

The activity concentrations of 238 U, 226 Ra and 210 Pb were modelled in Pinus sylvestris (Scots pine trees) on a uniform CaF 2-sludge heap in Belgium. The aim of this work is to enhance the knowledge of how transfer factors behave in NORM landfills. The simplest possible model in radioecology is used, which is based on Concentration Ratios (CR-s)...

The electric power that can be transmitted via high-voltage transmission lines is limited by the Joule heating of the conductors. In the case of coastal wind farms, the wind that produces power simultaneously contributes to the cooling of high-voltage overhead conductors. Ideally this would allow for increased power transmission or decreased dimens...

This study is based on AOD values from long-term re-analysis of atmospheric composition and air quality performed with SILAM model in Finnish Meteorological Institute. This study uses two spatial scales: global (1.44° Resolution, ERA-Interim re-analysis meteo data) and Northern Europe (0.1°, BaltAn65+ meteo). The emission information is compiled fr...

The Gaussian atmospheric dispersion model AEROPOL is validated against the classical Cabauw dispersion experiment, driven by (1) on-site meteorological data and (2) meteorological data from the numerical weather model HARMONIE. The meteorological forecast time used at the time of the release is 10 to 14 hours ahead of the analysis time. The results...

Two of the world's largest oil shale-fired power plants (PPs) in Estonia have been operational over 40 years, emitting various pollutants, such as fly ash, SOx, NOx, heavy metals, volatile organic compounds as well as radionuclides to the environment. The emissions from these PPs have varied significantly during this period, with the maximum during...

Few studies have investigated associations between self-reported and modelled exposure to traffic pollution. The objective of this study was to examine correlations between self-reported traffic exposure and modelled (a) NOX and (b) traffic proximity in seven different northern European cities; Aarhus (Denmark), Bergen (Norway), Gothenburg, Umeå, a...

The poster shows the activities to measure air ions, aerosols and their precursor gases at the SMEAR Estonia station.

Background: Traffic and residential heating are the main sources of particulate matter (PM) in Northern Europe. Wood is widely used for residential heating and vehicle numbers are increasing. Besides traffic exhaust, studded tires produce road dust that is the main source of traffic-related PM 10. Several studies have associated total PM mass with...

This study is focused on a wild-land fire episode in 2010, August 7–9, when the plume of severe wildfires in European part of Russia reached Estonia and southern Finland, thus giving a chance to evaluate the modelling results against a relatively dense network of air quality monitoring stations. The chemistry-transport model SILAM, driven by the EC...

The turbulence within and immediately above a vegetation canopy is the driver of the exchange processes of heat, trace gases and particles between the soil, the plants and the atmosphere above.

Handbook for the large public

The turbulence within and immediately above a vegetation canopy is the driver of the exchange processes of heat, trace gases and particles between the soil, the plants and the atmosphere above.

The SILAM model is running in Finnish Meteorological Institute (FMI) for European air quality forecasts (http://silam.fmi.fi). The 7 km resolution of both TNO-MACC emission grid and Nordic model domain is too coarse for urban and industrial areas. The Estonian modelling domain, operated jointly by the University of Tartu and Estonian Meteorological...

The Gaussian plume model AEROPOL 5 is applied to estimate the yearly average NO2 concentrations in Tartu, the second largest town of Estonia with about 100,000 inhabitants, for RHINE study. We apply the porosity concept by Genikhovich E, Gracheva I, Filatova E (Modelling of urban air pollution: principles and problems. In: Borrego C, Schayes G (eds...

Online coupled mesoscale meteorology atmospheric chemistry models have undergone a rapid evolution in recent years. Although mainly developed by the air quality modelling community, these models are also of interest for numerical weather prediction and regional climate modelling as they can consider not only the effects of meteorology on air qualit...

This study is aimed to assess the health impacts of outdoor PM2.5 concentrations to entire population of Estonia. As the air quality monitoring network in Estonia is rather sparse (six urban, three rural and a few industrial sites), the exposure assessment was based on long-term modelling, controlled by monitoring data from existing stations. The m...

The national communication describes Estonia´s vulnerability and the actions taken with regard to adapting to climate change. https://unfccc.int/files/national_reports/non-annex_i_natcom/application/pdf/est_nc6.pdf.

The simulation of the coupled evolution of atmospheric dynamics, pollutant transport, chemical reactions and atmospheric composition is one of the most challenging tasks in environmental modelling, climate change studies, and weather forecasting for the next decades as they all involve strongly integrated processes. Weather strongly influences air...

The SILAM model with built-in isoprene and monoterpene emission module from natural sources was run for May to August 2006 in Baltic Sea region. In this study VOCs were advected as passive tracers. Modelled hourly VOC-tracer concentrations were compared with sub-half-micrometre aerosol concentrations, simultaneously measured in Preila (Lithuania),...

The SILAM model (version 4.5.4) is applied for retrospective modelling of wintertime deposition fluxes of fly ash and sulphate near Estonian oil-shale-based industrial complex. The fluxes are validated against snow-based deposition measurements that have been carried out during nine winters since 1985. Also, the data from the Lahemaa (Estonia) and...

A modelling analysis of observations of aerosol concentrations during the LAPBIAT measurement campaign is presented and possible sources of the aerosols and their precursors are discussed. The LAPBIAT measurement campaign at the SMEAR I station at Värriö in eastern Lapland took place from 26 April to 11 May 2003 and registered a series of particle...

The hydrogen sulphide (H2S) and sulphur dioxide (SO2) data from Kalevi air quality monitoring station in the town of Kohtla-Järve, the centre of Estonian oil shale processing industry, and some episodic measurements from a nearby location, are analysed in view of wind direction and other meteorological parameters governing the atmospheric dispersio...

Particulate matter (PM) is the major air pollution problem with health impacts in Estonia. The prevailing sources of particles are traffic and local heating. In this study, we quantified the health effects of PM in neighbourhoods of five main cities with a health impact assessment (HIA) approach that uses information on exposure, baseline mortality...

The study reviews the emission estimates of sulphur oxides (SOx) and primary particulate matter (PM) from the major industrial sources of Kola Peninsula. Analysis of the disagreements between the existing emission inventories for the Kola region combined with forward and inverse ensemble dispersion modelling, analysis of observation time-series and...

The relationship between exposure to traffic induced particles, respiratory health and cardiac diseases was studied in the RHINE Tartu cohort. A postal questionnaire with commonly used questions regarding respiratory symptoms, cardiac disease, lifestyle issues such as smoking habits, indoor environment, occupation, early life exposure and sleep dis...

Peat will be used more widely for heating in Tartu (Estonia), therefore the potential health effects needed to be assessed. In transition from today's gas heating to burning of peat, the amount of exhaust gases emitted will increase and more than 100 000 people will be exposed to greater health risks. Based on the peat quality data, the emissions w...

Health impact assessments (HIA) use information on exposure, baseline mortality/morbidity and exposure-response functions from epidemiological studies in order to quantify the health impacts of existing situations and/or alternative scenarios. The aim of this study was to improve HIA methods for air pollution studies in situations where exposures c...

Traffic is the main factor affecting air quality in most cities. After the Estonian re-independence in 1991, the increase of motorization has been fast and car usage has intensified. During the same period, the average age of cars has decreased and thanks to improvements in engine technology, the emissions per km have been reduced. The objective wa...

Overview of current methodologies and tools for mesoscale meteorological model validation and result evaluation, on validation datasets and user training are provided. This overview will assist in the wider aim of COST 728 to enhance European capabilities on meteorological models for air pollution dispersion applications. This report is meant as a...

For tracing the sources of aerosol fractions measured in the campaign at Värriö, Finnish Lapland, spring 2003, the SILAM model was applied in two modes: (1) inverse (adjoint) run, with measured aerosol concentrations as the sensitivity source function; and (2) forward run with EMEP database of sulphur dioxide and particulate matter emissions. One o...

This paper is intended to clarify the geographical extent of processes leading to a nucleation event and the role of atmospheric transport in it. The study is based on the inverse (adjoint) runs of atmospheric advection-diffusion model SILAM and general knowledge on basic mechanisms and time scales of nanometer particle formation in the atmosphere....

As the pine trees at ombrotrophic bog grow in the extreme lack of nutrients deposited into the soil exclusively front the atmosphere, any increase of deposition affects the growth of trees remarkably. Radial increments of Pinus sylvestris in bog stands were studied at 6 sites in the North-Eastern Estonia, 7 sites in remote parts of Estonia, a site...

Rapidly growing number of cars, after the collapse of the Soviet Union, made the street pollution the most urgent air quality problem. Need for new traffic routes pushes the reconstruction of street network. Computations of maximal and annual mean concentrations of NOx, CO and PM2.5 from street and road traffic were performed applying the AEROPOL m...

The LAPBIAT measurement campaign took place in the Värriö SMEAR I measurement station located in Eastern Lapland in the spring of 2003 between 26 April and 11 May. In this paper we describe the measurement campaign, concentrations and fluxes of aerosol particles, air ions and trace gases, paying special attention to an aerosol particle formation ev...

Concentrations of Cd, Cr, Cu, Fe, Ni, Pb, V and Zn in epigeic mosses Pleurozium schreberi and Hylocomium splendens have been monitored in Estonia since 1989. It was found that the uptake of these metals, except Zn, had con-siderably decreased during this time, especially in the industrialised north-eastern part of the country. Obviously, the main r...

Introduction of a new combustion technology of oil shale - circulating fluidized bed (CFB) process in the Estonian and Baltic Power Plants (Narva PPs) - is an efficient way to reduce the emissions of SO2 from electric energy production in Estonia. In 2004-2005, the exploitation of CFB boilers in the renovated power unit No 8 at the Estonian PP show...

The improved Gaussian dispersion model AEROPOL (University of Tartu, Estonia) is validated against the Copenhagen air pollution dispersion dataset belonging to the Model Validation Kit of the Initiative on ''Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes''. Model updates include the application of: surface heat flux i...

The underlying surface effects to the dry deposition of airborne ingredients are well known at least in qualitative sense: rougher surface initiates stronger wind-induced turbulence and therefore, as a rule, larger deposition velocities. Nevertheless, the scatter in both cases — model versus model and model versus experiment — is often large. Obvio...

In countries having limited resources, it is difficult to assess urban air quality on contemporaneously, due to the absence of on-line information about air pollution levels and emission rates. An alternative approach is recommended for smaller cities with lower demands of resources. The applied scheme consists of a database of air pollution source...

The distribution of forest and open land determines highly the aerodynamic roughness of flat rural land, affecting dramatically the dispersion of passive admixtures. A case study using the weather forecast model HIRLAM is carried out. It was found that replacing the coarse-resolution land use database with a much finer one affects significantly the...

The air pollution modelling system used in Tartu (population 101,000) is aimed at examining the pollution levels in different meteorological conditions, and determining optimal traffic schemes and strategic development plans for the city. The system consists of: (i) a Gaussian plume model AEROPOL, and (ii) a database on sources of NO<sub align="rig...

Snow samples from 18 sites in Estonia were collected in February and March 1996 after 72–110 days of permanent snow cover. Three snow layers corresponding to different snow accumulation periods were separated in each sampling site. Snow water samples were analysed for sulphate (SO4 2-), nitrate (NO3 -), and chloride (Cl-) ions and elemental composi...

The AEROPOL and AEROFOUR dispersion models developed at Tartu Observatory (Estonia) are validated using the Lillestrom dataset and following the model comparison rules established at the workshop in Mol. Running the AEROFOUR model, the vertical wind and temperature co-variations not included into the official dataset were used. The computed and mea...

Field measurements of concentrations of SO 2 and NO 2 in the air and deposi-tion of Ca 2+ , Mg 2+ , K + , Na + , SO 4 2– , NO 3 – and Cl – in northeastern Estonia were carried out in the end of winter 1998/99. Concentrations in the air were measured by passive sampling method (Palmes tubes); snow samples were used to quantify the deposition loads....

The data set is based on field observations carried out in the north-east of Estonia during December 1995 – February 1996. The air pollutants were emitted from stacks of the Estonian and the Baltic thermal power plants (maximum capacity ca. 1.5 GW each), located at 17 km from each other. First of them has two 250 m high stacks, second four 150 m an...

The deposition loads of fly ash and sulfur have been high in the NE Estonia since the late fifties, when the oil shale energetics, chemical and cement industry achieved the remarkable extent. The combined effects of both pollutants have seriously damaged sensitive ecosystems (forest on podzolic soils and bog). The main effects are related with alka...

The Gaussian type air pollution dispersion and deposition model AEROPOL is developed at the Tartu Observatory, Estonia (Kaasik and Rõõm, 1997). The multiple reflections with partial adsorption from the underlying surface and capping inversion, as well as the initial rise of a buoyant plume with the inversion penetration, are included. The wet depos...

In Estonia (area 45 227 km² ) bioindication method to determine relative atmospheric deposition of Cd, Cr, Cu, Fe, Ni, Pb, V and Zn has been used for 16 years. The biomonitoring results are presented in the form of easily understandable territorial distribution maps of these trace elements. Point data are interpolated over the territory, using the...