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Hůnová I, Brabec M, Malý M. Ambient ozone at a rural Central European site and its vertical concentration gradient close to the ground. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:80014-80028. [PMID: 37291343 DOI: 10.1007/s11356-023-28016-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023]
Abstract
The representativeness of ambient air quality of an in situ measurement is key in the use and correct interpretation of the measured concentration values. Though the horizontal representativeness aspect is generally not neglected in air pollution studies, a detailed, high-resolution vertical distribution of ambient air pollutant concentrations is rarely addressed. The aim of this study is twofold: (i) to explore the vertical distribution of ground-level ozone (O3) concentrations measured at four heights above the ground-namely at 2, 8, 50, and 230 m-and (ii) to examine in detail the vertical O3 concentration gradient in air columns between 2 and 8, 8 and 50, and 50 and 230 m above the ground. We use the daily mean O3 concentrations measured continuously at the Košetice station, representing the rural Central European background ambient air quality observed during 2015-2021. We use the semiparametric GAM (generalised additive model) approach (with complexity or roughness-penalised splines implementation) to analyse the data with sufficient flexibility. Our models for both O3 concentrations and O3 gradients use (additive) decomposition into annual trend and seasonality (plus an overall intercept). The seasonal and year-to-year patterns of the modelled O3 concentrations look very similar at first glance. Nevertheless, a more detailed look through O3 gradients shows that they differ substantially with respect to their seasonal and long-term dynamics. The vertical O3 concentration gradient in 2-230 m is not uniform but changes substantially with increasing height and shows by far the highest dynamics near the ground between 2 and 8 m, differing in both the seasonal and annual aspects for all the air columns inspected. We speculate that non-linear changes of both seasonal and annual components of vertical O3 gradients are due to atmospheric-terrestrial interactions and to meteorological factors, which we will explore in a future study.
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Affiliation(s)
- Iva Hůnová
- Czech Hydrometeorological Institute, Na Sabatce 17, 143 06, Prague 4, Czech Republic.
- Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benatska 2, 128 00, Prague 2, Czech Republic.
| | - Marek Brabec
- Institute of Computer Science of the Czech Academy of Sciences, Pod Vodarenskou vezi 2, 182 07, Prague 8, Czech Republic
- National Institute of Public Health, Srobarova 48, 100 00, Prague 10, Czech Republic
| | - Marek Malý
- Institute of Computer Science of the Czech Academy of Sciences, Pod Vodarenskou vezi 2, 182 07, Prague 8, Czech Republic
- National Institute of Public Health, Srobarova 48, 100 00, Prague 10, Czech Republic
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Nováková T, Navrátil T, Schütze M, Rohovec J, Matoušková Š, Hošek M, Matys Grygar T. Reconstructing atmospheric Hg levels near the oldest chemical factory in central Europe using a tree ring archive. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 304:119215. [PMID: 35358634 DOI: 10.1016/j.envpol.2022.119215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 03/07/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
The Chemical Factory in Marktredwitz (CFM) is known as the oldest chemical factory in Germany (1778-1985), and from the beginning of the 20th century focused primarily on the production of mercury (Hg) compounds. Due to extensive pollution, together with employee health issues, the CFM was shut in 1985 by a government order and remediation works proceeded from 1986 to 1993. In this study, tree ring archives of European Larch (Larix decidua Mill.) were used to reconstruct changes of air Hg levels near the CFM. Mercury concentrations in larch boles decreased from 80.6 μg kg-1 at a distance of 0.34 km-3.4 μg kg-1 at a distance of 16 km. The temporal trend of atmospheric Hg emissions from the CFM reconstructed from the tree ring archives showed two main peaks. The first was in the 1920s, with a maximum tree ring Hg concentration 249.1 ± 43.9 μg kg-1 coinciding with when the factory had a worldwide monopoly on the production of Hg-based seed dressing fungicide. The second peak in the 1970s, with a maximum tree ring Hg concentration of 116.4 ± 6.3 μg kg-1, was associated with a peak in the general usage and production of Hg chemicals and goods. We used the tree ring record to reconstruct past atmospheric Hg levels using a simple model of Hg distribution between the larch tree rings and atmosphere. The precision of the tree ring model was checked against the results of air Hg measurements during the CFM remediation 30 years ago. According to the tree ring archives, the highest air Hg concentrations in the 1920s in Marktredwitz were over 70 ng m-3. Current air Hg levels of 1.18 ng m-3, assessed in the city of Marktredwitz, indicate the lowest air Hg in the past 150 years, underscoring the effective remediation of the CFM premises 30 years ago.
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Affiliation(s)
- Tereza Nováková
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00, Prague 6, Czech Republic
| | - Tomáš Navrátil
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00, Prague 6, Czech Republic.
| | - Martin Schütze
- Institut für Geoökologie, AG Umweltgeochemie, Technische Universität Braunschweig, Langer Kamp 19C, 38106, Braunschweig, Germany
| | - Jan Rohovec
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00, Prague 6, Czech Republic
| | - Šárka Matoušková
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00, Prague 6, Czech Republic
| | - Michal Hošek
- Institute of Inorganic Chemistry of the Czech Academy of Sciences, 250 01, Řež, Czech Republic; Faculty of Environment, J.E. Purkyně University in Ústí nad Labem, Pasteurova 3632/15, 400 96, Ústí nad Labem, Czech Republic
| | - Tomáš Matys Grygar
- Institute of Inorganic Chemistry of the Czech Academy of Sciences, 250 01, Řež, Czech Republic
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Characteristics of summer hourly precipitation under different urbanization background in central China. Sci Rep 2022; 12:7551. [PMID: 35534519 PMCID: PMC9085755 DOI: 10.1038/s41598-022-11487-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/22/2022] [Indexed: 11/17/2022] Open
Abstract
The relationship between sub-daily precipitation and urbanization is widely concerned because short-term precipitation is sensitive to urbanization and difficult to predict. Using the data of summer hourly precipitation and urban development during 2007–2019 at four urban stations and an atmospheric background monitoring station in central China, this study investigates the characteristics of hourly precipitation and hourly extreme precipitation (HEP) under different urbanization background. It is found that high urbanization level may benefit precipitation intensity but not for accumulated precipitation amount and precipitation frequency, and it is also conducive to the occurrence of hourly precipitation within [20, 50) mm. Precipitation amount and frequency for hourly precipitation within [5, 50) mm have similar diurnal variation at fixed station, yet the diurnal variation of precipitation intensity is insignificant. The differences in temporal variation of precipitation are related to urbanization and terrain. Both high urbanization level and speed are conducive to summer HEP; especially summer HEP intensity may increase gradually under sustainable urbanization development. Although growth-type HEP occurs frequently with main contribution to total HEP precipitation amount in central China regardless of urbanization level, the frequency and contribution of continuous-type HEP tends to increase under high urbanization level and speed.
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The Influence of Ozone on Net Ecosystem Production of a Ryegrass–Clover Mixture under Field Conditions. ATMOSPHERE 2021. [DOI: 10.3390/atmos12121629] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In order to understand the effect of phytotoxic tropospheric ozone (O3) on terrestrial vegetation, we quantified the impact of current O3 concentration ([O3]) on net ecosystem production (NEP) when compared to the conditions of the pre-industrial era. We compared and tested linear mixed-effects models based on [O3] and stomatal O3 flux (Fsto). The managed ryegrass–clover (Lolium perenne and Trifolium pratense) mixture was grown on arable land in the Czech Republic, Central Europe. Values of [O3] and Fsto were measured and calculated based on resistance analogy, respectively, while NEP was calculated from eddy covariance CO2 fluxes. We found the Fsto-based model more precise when compared to measured NEP. High Fsto was found even at low [O3], while broad summer maximum of [O3] was not necessarily followed by significant NEP decline, due to low soil water content leading to a low stomatal conductivity and Fsto. Comparing to low pre-industrial O3 conditions, current levels of O3 resulted in the reduction of cumulative NEP over the entire growing season, up to 29.7 and 13.5% when the [O3]-based and Fsto-based model was applied, respectively. During the growing season, an O3-induced reduction of NEP ranged between 13.1% in May and 26.2% in July when compared to pre-industrial Fsto levels. Looking to the future, high [O3] and Fsto may lead to the reduction of current NEP by approximately 13.3% on average during the growing season, but may increase by up to 61–86.6% in autumn, indicating further O3-induced acceleration of the senescence. These findings indicate the importance of Fsto and its inclusion into the models estimating O3 effects on terrestrial vegetation. The interaction between environmental factors and stomatal conductance is therefore discussed in detail.
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Mbengue S, Zikova N, Schwarz J, Vodička P, Šmejkalová AH, Holoubek I. Mass absorption cross-section and absorption enhancement from long term black and elemental carbon measurements: A rural background station in Central Europe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148365. [PMID: 34198082 PMCID: PMC8434419 DOI: 10.1016/j.scitotenv.2021.148365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/24/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Black carbon (BC) is a dominant aerosol light absorber, and its brown carbon (BrC) coating can enhance absorption and lead to uncertainties concerning the radiative forcing estimation. This study investigates the mass absorption cross-section of equivalent BC (MACeBC) during a long-term field measurement (2013-2017) at a rural Central European site. The MAC enhancement factor (Eabs) and the contribution of BrC coatings to the absorption coefficient (Babs) were estimated by combining different approaches. The annual mean Babs and MACeBC values decreased slightly over the measurement period associated with change in the submicron aerosol size distribution. Regardless of the wavelength, Babs exhibited clear seasonal and diurnal variations, with higher values in winter when a higher absorption Ångström exponent (1.4) was observed due to the local biomass burning (BB). In contrast, MACeBC did not have a distinct temporal trend at 600 nm (7.84 ± 2.79 m2 g-1), while it showed a seasonal trend at 370 nm with higher values in winter (15.64 ± 4.77 m2 g-1). During this season, Eabs_660 was 1.18 ± 0.27 and did not exhibit any clear wavelength dependence, despite the influence of BB. During the study period, BrC-attributed absorption was observed in 31% of the samples, with a contribution of up to 40% of total Babs. In summer, the Eabs_660 increased to 1.59 ± 0.60, when a larger BC coating could be formed by secondary aerosol fractions. During this season, MACeBC_660 and Eabs_660 showed comparable source profiles that were mainly associated with aged air masses over central Europe, thereby supporting the fact that characteristics of coating materials formed during atmospheric aging are a major factor driving the MACeBC_660 measured at the regional background site. Further field investigations of the composition of BC coatings would help to better understand and estimate uncertainties related to the radiative effect of aerosols.
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Affiliation(s)
- Saliou Mbengue
- Global Change Research Institute of the CAS, Brno 603 00, Czech Republic.
| | - Nadezda Zikova
- Institute of Chemical Process Fundamentals of the CAS, Prague 180 00, Czech Republic
| | - Jaroslav Schwarz
- Institute of Chemical Process Fundamentals of the CAS, Prague 180 00, Czech Republic
| | - Petr Vodička
- Institute of Chemical Process Fundamentals of the CAS, Prague 180 00, Czech Republic
| | - Adéla Holubová Šmejkalová
- Czech Hydrometeorological Institute, Košetice Observatory, Košetice 394 22, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Prague 128 01, Czech Republic
| | - Ivan Holoubek
- Global Change Research Institute of the CAS, Brno 603 00, Czech Republic; RECETOX, Masaryk University, Brno 625 00, Czech Republic
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Nováková T, Navrátil T, Demers JD, Roll M, Rohovec J. Contrasting tree ring Hg records in two conifer species: Multi-site evidence of species-specific radial translocation effects in Scots pine versus European larch. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:144022. [PMID: 33360336 DOI: 10.1016/j.scitotenv.2020.144022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/10/2020] [Accepted: 11/17/2020] [Indexed: 05/21/2023]
Abstract
Tree ring records are increasingly being used as a geochemical archive of past atmospheric mercury (Hg) pollution. However, it is not clear whether all tree species can be used reliably for this purpose. We compared tree-ring Hg records of two coniferous species - widely used Scots pine (Pinus sylvestris) and less frequently used European larch (Larix decidua) at 6 study sites across the Czech Republic. Site-specific mean Hg concentrations in tree-ring segments of larch ranged from 2.1 to 5.2 μg kg-1, whereas pine had higher mean Hg concentrations (3.6-8.3 μg kg-1). Temporal records of Hg concentrations in tree rings of larch and pine differed significantly. Comparisons with previously documented peat Hg records showed that larch tree-ring Hg records more closely agreed with peat archive records. For pines, which had a large, tree-age dependent number of sapwood rings (62 ± 17, 1SD), we found a strong relationship between the year of peak Hg and the number of sapwood tree rings (p = 0.012, r2 = 0.35), as well as between peak Hg year and the sapwood-heartwood boundary year (p < 0.001, r2 = 0.65), rather than with temporal changes in atmospheric Hg levels. The much greater number of pine sapwood tree rings appears to promote radial Hg translocation, resulting in the shift of Hg peaks backward in time through the tree-ring record. In contrast, Larch consistently had a low number of sapwood tree rings (19 ± 6, 1SD), and more closely agreed with peat Hg records. This study suggests that European larch, a tree species characterized by a relatively low and consistent number of sapwood tree rings, records changes in atmospheric Hg concentrations more reliably than does Scots pine, a species with a relatively high and variable number of sapwood tree rings.
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Affiliation(s)
- Tereza Nováková
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00 Prague 6, Czech Republic.
| | - Tomáš Navrátil
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00 Prague 6, Czech Republic
| | - Jason D Demers
- University of Michigan, 1100 North University Ave., Ann Arbor, MI 48109, United States of America
| | - Michal Roll
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00 Prague 6, Czech Republic
| | - Jan Rohovec
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00 Prague 6, Czech Republic
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Mbengue S, Serfozo N, Schwarz J, Ziková N, Šmejkalová AH, Holoubek I. Characterization of Equivalent Black Carbon at a regional background site in Central Europe: Variability and source apportionment ☆. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:113771. [PMID: 31991342 DOI: 10.1016/j.envpol.2019.113771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/29/2019] [Accepted: 12/07/2019] [Indexed: 05/08/2023]
Abstract
Characterizing Black Carbon (BC) at regional background areas is important for better understanding its impact on climate forcing and health effects. The variability and sources of Equivalent Black Carbon (EBC) in PM10 (atmospheric particles with aerodynamic diameter smaller than 10 μm) have been investigated during a 5-year measurement period at the National Atmospheric Observatory Košetice (NAOK), Czech Republic. Ground based measurements were performed from September 2012 to December 2017 with a 7-wavelength aethalometer (AE31, Magee Scientific). The contributions of fossil fuel (EBCff) and biomass burning (EBCbb) were estimated using the aethalometer model. Seasonal, diurnal and weekly variations of EBC were observed that can be related to the sources fluctuations and transport characteristic of pollutants predominantly associated with regional air masses recirculating over the Czech Republic and neighboring countries. The absorption Ångström exponent (α-value) estimated in summer (1.1 ± 0.2) was consistent with reported value for traffic, while the mean highest value (1.5 ± 0.2) was observed in winter due to increased EBCbb accounting for about 50% of the total EBC. This result is in agreement with the strong correlation between EBCbb and biomass burning tracers (levoglucosan and mannosan) in winter. During this season, the concentrations of EBCbb and Delta-C (proxy for biomass burning) reached a maximum in the evening when increasing emissions of wood burning in domestic heating devices (woodstoves/heating system) is expected, especially during the weekend. The diurnal profile of EBCff displays a typical morning peak during the morning traffic rush hour and shows a decreasing concentration during weekends due to lower the traffic emission.
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Affiliation(s)
- Saliou Mbengue
- CzechGlobe - Global Change Research Institute CAS, Brno, 60300, Czech Republic.
| | - Norbert Serfozo
- CzechGlobe - Global Change Research Institute CAS, Brno, 60300, Czech Republic
| | - Jaroslav Schwarz
- Institute of Chemical Process Fundamentals CAS, Prague, CZ18000, Czech Republic
| | - Nadezda Ziková
- Institute of Chemical Process Fundamentals CAS, Prague, CZ18000, Czech Republic
| | - Adéla Holubová Šmejkalová
- CzechGlobe - Global Change Research Institute CAS, Brno, 60300, Czech Republic; Institute of Chemical Process Fundamentals CAS, Prague, CZ18000, Czech Republic; Czech Hydrometeorological Institute, Košetice Observatory, Košetice, 394 22, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Prague, 128 01, Czech Republic
| | - Ivan Holoubek
- CzechGlobe - Global Change Research Institute CAS, Brno, 60300, Czech Republic; Research Centre for Toxic Compounds in the Environment, Masaryk University, Brno, 62500, Czech Republic
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Navrátil T, Nováková T, Shanley JB, Rohovec J, Matoušková Š, Vaňková M, Norton SA. Larch Tree Rings as a Tool for Reconstructing 20th Century Central European Atmospheric Mercury Trends. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11060-11068. [PMID: 30192133 DOI: 10.1021/acs.est.8b02117] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We propose the tree rings of European Larch ( Larix decidua) as a widely available and reliable geochemical archive of local and regional changes in atmospheric mercury (Hg). Mean Hg concentrations in larch tree rings from 8 background sites across the Czech Republic ranged from 2.2 to 4.8 μg kg-1; the maximum concentrations occurred in the period 1951-1970. At 3 sites impacted by Hg-emission sources [gold amalgamation processing, caustic soda production, and lead (Pb) ore smelting] mean larch tree ring Hg concentrations were significantly elevated relative to background sites. Changes in larch tree ring Hg concentrations were temporally coherent with known activities at the sites that would alter Hg emissions; the nearly simultaneous response in tree rings indicated little or no translocation of Hg within the larch bole. Based on the present-day atmospheric Hg concentration of 1.63 ng m-3 at the intensively monitored Czech Global Mercury Observation System site and the most recent mean tree ring Hg concentration of 2.8 μg kg-1 in co-located larch trees, we developed a simple distribution model of Hg between the atmosphere and larch tree rings. We applied the model using observed changes of Hg in larch tree rings from the countrywide background sites to reconstruct past atmospheric Hg concentrations in central Europe. Modeled Hg concentrations were in agreement with annual means from the European Monitoring and Evaluation Programme observatories.
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Affiliation(s)
- Tomáš Navrátil
- Institute of Geology of the Czech Academy of Science , Rozvojova 269 , 165 00 Prague , Czech Republic
| | - Tereza Nováková
- Institute of Geology of the Czech Academy of Science , Rozvojova 269 , 165 00 Prague , Czech Republic
| | - James B Shanley
- United States Geological Survey , PO Box 628, Montpelier , Vermont 05601 , United States
| | - Jan Rohovec
- Institute of Geology of the Czech Academy of Science , Rozvojova 269 , 165 00 Prague , Czech Republic
| | - Šárka Matoušková
- Institute of Geology of the Czech Academy of Science , Rozvojova 269 , 165 00 Prague , Czech Republic
| | - Maria Vaňková
- Institute of Geology of the Czech Academy of Science , Rozvojova 269 , 165 00 Prague , Czech Republic
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Fusek M, Michálek J. Left-Censored Samples from Skewed Distributions: Statistical Inference and Applications. ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS 2018. [DOI: 10.11118/actaun201866010245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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