Asta Gregorič

New particle formation (NPF) is considered a major source of aerosol particles and cloud condensation nuclei (CCN); however, our understanding of NPF and the subsequent particle growth mechanisms in coastal areas remains limited. This study provides evidence of frequent NPF events followed by particle growth in the middle Adriatic Sea during the su...

Recent years have seen an increase in the use of wood for energy production of over 30 %, and this trend is expected to continue due to the current energy crisis and geopolitical instability. At present, residential wood burning (RWB) is one of the most important sources of organic aerosols (OAs) and black carbon (BC), posing a significant risk to...

Light-absorbing aerosols (LAA) impact the atmosphere by heating it. Their effect in the Arctic was investigated during two summer Arctic oceanographic campaigns (2018 and 2019) around the Svalbard Archipelago in order to unravel the differences between the Arctic background and the local anthropic settlements. Therefore, the LAA heating rate (HR) w...

Machine learning-based characterization of collected black carbon and desert dust using HIM microscopy supporting real-time Aethalometer measurements.

Recent years have seen an increase in the use of wood for energy production of over 30%, and this trend is expected to continue due to the current energy crisis and geopolitical instability. At present, residential wood burning (RWB) is one of the most important sources of organic aerosols (OA) and black carbon (BC). While BC is recognized for its...

The Camp Fire was one of California's deadliest and most destructive wildfires, and its widespread smoke threatened human health over a large area in Northern California in November 2018. To analyze the Camp Fire influence on air quality on a 200 km distant site in Berkeley, highly time-resolved total carbon (TC), black carbon (BC), and organic car...

A recently-developed radon-based method for combined classification of both diurnal and synoptic timescale changes in the atmospheric mixing state is applied to 1-year of observations in Ljubljana (capital of Slovenia). Five diurnal-timescale mixing classes (#1 to #5) were defined for each season along with an additional mixing class (#6) in non-su...

Black carbon (BC) aerosol typically has two major sources in the urban environment: traffic and domestic biomass burning, which has a significant contribution to urban air pollution during the heating season. Traffic emissions have been widely studied by both laboratory experiments (individual vehicle emission) and real-world measurement campaigns...

Airborne meteorological and aerosol measurements have been performed in Longyearbyen (Svalbard islands) in the Summer of 2018, coupling an instrumental aerosol payload with a meteorological radiosonde deployed on a tethered balloon. More than 70 vertical profiles of aerosol and meteorological properties have been recorded up to a maximum altitude o...

Particulate matter (PM) pollution is one of the major threats to cultural heritage outdoors. It has been recently implied that organic aerosols will prevail over inorganic carbon particulates in the future, changing the main mechanisms of damage caused by poor air quality to calcareous heritage in particular. We studied fresh particulate deposits o...

Aerosol direct radiative forcing is strongly dependent on aerosol distributions and aerosol types. A detailed understanding of such information is still missing at the Alpine region, which currently undergoes amplified climate warming. Our goal was to study the vertical variability of aerosol types within and above the Vipava valley (45.87°N, 13.90...

In recent years, carbonaceous aerosols (CA) have been recognized as a significant contributor to the concentration of particles smaller than 2.5 μm (i.e., PM2.5), with a negative impact on public health and Earth's radiative balance. In this study, we present a method for CA apportionment based on high-time-resolution measurements of total carbon (...

As explained in the latest Arctic Monitoring and Assessment Programme (AMAP) report released in early 2021, the Arctic has warmed 3 times more quickly than the planet as a whole, as well as faster than previously thought. The Siberian Arctic is of great interest mainly because observations are sparse or largely lacking. A research aerosol station h...

Residential wood combustion is a widespread practice in Europe with a serious impact on air quality, especially in mountainous areas. While there is a significant number of studies conducted in deep urbanized valleys and basins, little is known about the air pollution processes in rural shallow hollows, where around 30 % of the people in mountainou...

Black carbon aerosol (BC) typically has two major sources in the urban environment; traffic, and domestic biomass burning which has a significant contribution to urban air pollution during the heating season. Traffic emissions have been widely studied by both laboratory experiments (individual vehicle emission) and real-world measurement campaigns...

Ljudje lahko preživimo tri tedne brez hrane in tri dni brez vode ter le nekaj minut brez zraka. Vendar zrak jemljemo za nekaj samoumevnega. Onesnaženega zraka, ki ga dihamo, večinoma ne vidimo, vendar pa ima številne negativne učinke na naše zdravje in zdravje naših otrok (Fuller, 2019). V Sloveniji zaradi z delci onesnaženega zraka prezgodaj umre...

As explained in the latest Arctic Monitoring and Assessment Programme (AMAP) report released in early 2021, the Arctic has warmed three times more quickly than the planet as a whole, and faster than previously thought. The Siberian Arctic is of great interest largely because observations are sparse or largely lacking. A research aerosol station has...

Residential wood combustion is a widespread practice in Europe with a serious impact on air quality, especially in 15 mountainous areas. While there is a significant number of studies conducted in deep urbanized valleys and basins, little is known about the air pollution processes in rural shallow hollows where around 30 % of the people in mountain...

To investigate the temporal variation of aerosol optical properties and evaluate the main emission sources of black carbon (BC) considering different seasons in a typical Mediterranean coastal environment, a field campaign was conducted during February–July 2019 at the Central Adriatic coastal area. Real-time measurements of aerosol light absorptio...

Black carbon (BC) is recognized as the primary pollutant resulting from incomplete combustion of mostly fossil fuels and biomass. It is the most light-absorbing fraction of fine particulate matter (PM) and a major contributor to climate change. Studies of BC temporal variations and sources are so far predominantly limited to winter campaigns perfor...

Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coe...

The atmospheric concentration of black carbon (BC) has paramount importance worldwide due to its role in global warming and its adverse effect on human health. Only limited information is available about BC concentration and emission factors from the Arabian/Persian Gulf region despite the presence of significant sources including petrochemical ind...

In the frame of the EMEP/ACTRIS/COLOSSAL campaign in Milan during winter 2018, equivalent black carbon measurements using the Aethalometer 31 (AE31), the Aethalometer 33 (AE33), and a Multi-Angle Absorption Photometer (MAAP) were carried out together with levoglucosan analyses on 12 h resolved PM2.5 samples collected in parallel. From AE31 and AE33...

We experimentally quantified the impact of cloud fraction and cloud type on the heating rate (HR) of black and brown carbon (HRBC and HRBrC). In particular, we examined in more detail the cloud effect on the HR detected in a previous study (Ferrero et al., 2018). High-time-resolution measurements of the aerosol absorption coefficient at multiple wa...

Air pollution is not an exclusively urban problem as wood burning is a widespread practice in rural areas. As we lack information on the air quality situation in rural mountainous regions, our aim is to examine equivalent black carbon (eBC) pollution in a typical rural karst area in the settlement of Loški Potok (Slovenia). eBC mass concentrations...

We present a new method for the determination of the source-specific black carbon emission rates. The methodology was applied in two different environments: an urban location in Ljubljana and a rural one in the Vipava valley (Slovenia, Europe), which differ in pollution sources and topography. The atmospheric dynamics was quantified using the atmos...

In the frame of the EMEP/ACTRIS/COLOSSAL campaign in Milan during winter 2018, equivalent black carbon measurements using the Aethalometer 31 (AE31), the Aethalometer 33 (AE33), and the Multi-Angle Absorption Photometer (MAAP) were carried out together with levoglucosan analyses on 12-h resolved PM2.5 samples collected in parallel. From AE31 and AE...

Aerosol particles are essential constituents of the Earth's atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence times, resulting in a highly heterogeneous...

Abstract. We experimentally quantified the impact of cloud fraction and cloud type on the heating rates (HRs) of black and brown carbon (HR_BC and HR_BrC).In particular, in this work, we examine in more detail the average cloud effect (Ferrero et al., 2018) using high time-resolution measurements of aerosol absorption at multipl...

Atmosfersko onečišćenje danas daleko premašuje svaki drugi oblik zagađenja. Brojne onečišćujuće tvari, uključujući lebdeće čestice ili aerosole, kontinuirano se emitiraju i formiraju u atmosferi kao posljedica prirodnih i/ili antropogenih aktivnosti. Među sastavnicama aerosola, crni ugljik (engl. black carbon, BC) primarna je onečišćujuća tvar koja...

Abstract. Aerosol particles are essential constituents of the Earth’s atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence time resulting in a highly heter...

Abstract. We present a new method for the determination of the source specific black carbon emission rates. The methodology was applied in two different environments: an urban location in Ljubljana and a rural one in the Vipava valley (Slovenia, Europe), which differ in pollution sources and topography. The atmospheric dynamics was quantified using...

Vipava valley in Slovenia is a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin. Aerosol loading distributions and optical properties were investigated using a two-wavelength polarization Raman LiDAR, which provided extinction coefficient, backscatter coefficient, depolarization ratio,...

The paper presents a study of air pollution caused by black carbon (BC) and fine particulate matter (PM) carried out in the rural area of the municipality of Loški Potok in the winter season of 2017/2018. Measurements of pollutants were performed at two different locations, one at Retje, a village at the bottom of a karst depression, and the other...

Aerosol vertical profiles are valuable inputs for the evaluation of aerosol transport models, in order to improve the understanding of aerosol pollution ventilation processes which drive the dispersion of pollutants in mountainous regions. With the aim of providing high-accuracy vertical distributions of particle mass concentration for the study of...

Light Absorbing Aerosols (LAA) absorb sunlight and heat the atmosphere. This work presents a novel methodology to experimentally quantify the heating rate (HR) induced by LAA into an atmospheric layer. Multi-wavelength aerosol absorption measurements were coupled with spectral measurements of the direct, diffuse and surface reflected radiation to o...

Traffic air pollution significantly influences cyclists using cycling routes near main roads. We analyze the dependency of black carbon (BC) concentrations in relation to the proximity to their traffic sources. We performed static and mobile measurements of BC using aethalometers at chosen sites and cycling routes in Celje, Slovenia—static measurem...

This work aims at evaluating mercury (Hg) occurrence, spatial distribution and speciation in groundwater of the Isonzo/Soča River upper alluvial plain downstream from the Idrija Hg mine (Western Slovenia). Several wells and piezometers were sampled both in static and dynamic mode. Total (THg) and filtered (FHg) concentrations were generally higher...

The paper presents the map of intrinsic groundwater vulnerability of the Isonzo/Soča High Plain, which is located between the Collio Hills and the Classical Karst Region and holds an aquifer shared between Italy and Slovenia. The map, produced at a scale of 1:25,000 and printed in A0 format, was obtained by means of the SINTACS method and shows the...

Year-long continuous radon monitoring was carried out (using Sarad Radon Scout devices) in a dwelling with high radon levels in the karst region of Slovenia. Two living rooms were selected: one on the ground floor with normal housework activities; and the second, on the first floor, closed and unattended. Meteorological data were also recorded. The...

Black carbon is a primary aerosol tracer for high-temperature combustion emissions and can be used to characterize the time evolution of its sources. It is correlated with a decrease in public health and contributes to atmospheric warming. Black carbon measurements are usually conducted with absorption filter photometers, which are prone to the fil...

Global carbon estimates have identified abiotic CO2 as a potentially significant source of atmospheric CO2, albeit little is known about its origin. The aim of this study was to identify the origin of soil CO2 using carbon isotopes and 222Rn data. The study involved collecting data from seven Slovenian forest soils developed over bedrock with contr...

Radon has been surveyed in 51 dwellings in the vicinity of an open-cast lignite mine and two lignite-fired power plants in the Pristina region, Kosovo. CR-39 solid-state nuclear track detectors were exposed in the period from March to June 2014. Radon activity concentration ranged from 41 Bq m−3 to 327 Bq m−3, and the resulted annual effective dose...

Increasing attention has been paid to radon in both Slovenia and Kazakhstan. The paper reviews their activities in radon measurements and dose estimates for radon exposure mitigation. Slovenia succeeded to accomplish the main goal of managing exposure to radon in homes and at workplaces at acceptably low levels, while in Kazakhstan there are still...

In soil samples collected from 58 points of 7 different lithological units that appear most often in Slovenia, emanation fraction of 222Rn and porosity have been determined. Emanation fraction ranged from 0.010 to 0.547 and varied substantially among lithological units, as well as within the same lithological unit. The highest average value was fou...

Radon concentration and cave temperature were studied at two morphologically different locations (the Beautiful Caves—BC and the lowest point—LP) in Postojna Cave (Slovenia). Radon concentration was considered a trace gas for cave ventilation research, where cave temperature was used as a supported microclimatic parameter. The influence of several...

The radon (222Rn) activity concentration in 15 dwellings in the Planej village and 10 dwellings in the Gorozhup village has been measured with the aim to complement the national radon survey and to compare the results of two different measurement techniques. The radon concentration has been measured in winter and spring using alpha scintillation ce...

In soil samples collected from 58 points over 7 different lithological units most often appearing in Slovenia, at which radon in indoor and outdoor air and in soil gas had been measured in previous surveys, emanation fraction of 222Rn has been determined. The number of samples for a unit differed and was the highest for carbonates which cover more...

At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn) decay products and the number concentration and size distribution of aerosol particles in the size range of 10-1100 nm were monitored, with the focus on the unattached fraction (fun) of radon decay products (RnDPs), a key parameter in radon dos...

Measurements of radon concentration were performed at three geomorphologically different locations in Postojna Cave, Slovenia. In the part of the cave open to visitors, annual average radon activity concentrations of 3255 ± 1190 Bq m-3 and 2315 ± 1019 Bq m-3 were found at the lowest point (LP) and in the Lepe jame (Beautiful Caves, BC), respectivel...

At the lowest point along the tourist route in the Postojna Cave, the activity concentration of radon ((222)Rn) short-lived decay products and number concentration and size distribution of background aerosol particles in the size range of 10-1100 nm were measured. In the warm yearly season, aerosol concentration was low (52 cm(-3)) with 21 % partic...

Postojna Cave is the biggest of 21 show caves in Slovenia and one of present day's most visited show caves in the world. Long and branched out cave system, large entrances at different levels, inflow of the Pivka river, and large variation of the outdoor air temperature and precipitation, make the Postojna Cave also a very complex climatic system i...

carbon dioxide, radon

Postojna Cave is the largest of 21 show caves in Slovenia. The radon concentration there was measured continuously in the Great Mountain hall from July 2005 to October 2009 and ranged from about 200 Bq m(-3) in winter to about 3 kBq m(-3) in summer. The observed seasonal pattern of radon concentration is governed by air movement due to the differen...

Orogen-parallel NW-SE trending faults with right-lateral offsets are ubiquitous in the Dinaric orogen. These faults consistently cut and displace thrusting-related structures and are therefore commonly interpreted as belonging to the final stage of tectonic evolution of the Dinarides (e.g. PICHA, 2002). In central Slovenia (northwestern External Di...

Dependence of radon levels in the Postojna Cave on outdoor air temperature

The Ravne tectonic fault in north-west (NW) Slovenia is one of the faults in this region, responsible for the elevated seismic activity at the Italian-Slovene border. Five measurement profiles were fixed in the vicinity of the Ravne fault, four of them were perpendicular and one parallel to the fault. At 18 points along these profiles the following...

The Ravne tectonic fault in north-west Slovenia is one of the faults in this region, responsible for the elevated seismic activity at the Italian-Slovene border. At 18 points along five profiles, four perpendicular and one parallel to the fault, the following measurements have been carried out: radon activity concentration in soil gas, using an Alp...

Radon concentration in thermal springs at Hotavlje and Bled has been measured from October 2005 to June 2008 and from October 2005 to September 2007, respectively. At both locations several anomalies in radon concentration were observed, that might have been caused by seismic events. In this study all earthquakes with ratio (D/R) between strain rad...

Vertical profiles of radioactive radon gas ((222)Rn) and dissolved gaseous mercury (DGM) in seawater in the Mediterranean Basin have been measured. They were found in the range 1.7-19.3 Bq m(-3) and 22-200 ng m(-3), respectively, at the bottom and 2.0-20.0 Bq m(-3) and 6-80 ng m(-3), respectively, at the surface. Preliminary results indicate a posi...

Indoor air radon concentration was measured by exposing etched track detectors in the sleeping and living rooms of 18 houses in 6 villages of the Sharri community in Kosovo. Values ranged from 24 to 209 Bq m−3, with only one exceeding 200 Bq m−3, with a geometric mean and geometric standard deviation of 95.4 Bq m−3 and 1.6, respectively. On the bas...

Air radon concentration was measured in summer and winter at 11 points along the tourist guided route in the Gadime Cave in Kosovo using alpha scintillation cells and etched track detectors. At two points in summer, values higher than 1700Bqm(-3) were observed; they otherwise were in the range 400-1000Bqm(-3). Values were lower in winter. The effec...