| 1. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Observations of Ground-level Ozone and NO2 in Northernmost Sweden, Including the Scandian Mountain Range
- 2009
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Ingår i: Ambio. ; 38:8, s. 448-451
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Tidskriftsartikel (refereegranskat)abstract
- Ozone was measured using passive diffusion samplers at alpine Latnjajaure (980 m above sea level [asl]) in the northern Scandian Mountain Range during spring and summer 2006–2008, and year-round at three further sites in northernmost Sweden 2004–2008. These observations were compared with ozone concentrations from three permanent monitoring stations using ultraviolet absorption instruments. Ozone concentrations at Latnjajaure were higher than at the closest monitoring site, illustrating the importance of high elevation for ozone. At the northern sites the ozone spring peak was more pronounced, higher, and earlier (April maximum) compared to a site in south Sweden (May maximum). During summer, ozone concentrations were higher in south Sweden. Presently, the growing season largely starts after the ozone spring peak in north Sweden but is likely to start earlier in the future climate. This could lead to an increased risk for ozone effects on vegetation if the current yearly ozone cycle persists.
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| 2. |
- Andersson, Camilla, et al.
(författare)
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Climate change modifies air quality
- 2009
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Ingår i: Air pollution & climate change - Two sides of the same coin? Editor Håkan Pleijel, University of Gothenburg. - Stockholm : Swedish Environmental Protection Agency. - 9789162012786 ; , s. 79-87
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Andersson-Sköld, Yvonne, et al.
(författare)
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A framework for assessing urban greenery's effects and valuing its ecosystem services
- 2018
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Ingår i: Journal of Environmental Management. - : Academic Press. - 0301-4797 .- 1095-8630. ; 205, s. 274-285
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Tidskriftsartikel (refereegranskat)abstract
- Ongoing urban exploitation is increasing pressure to transform urban green spaces, while there is increasing awareness that greenery provides a range of important benefits to city residents. In efforts to help resolve associated problems we have developed a framework for integrated assessments of ecosystem service (ES) benefits and values provided by urban greenery, based on the ecosystem service cascade model. The aim is to provide a method for assessing the contribution to, and valuing, multiple ES provided by urban greenery that can be readily applied in routine planning processes. The framework is unique as it recognizes that an urban greenery comprises several components and functions that can contribute to multiple ecosystem services in one or more ways via different functional traits (e.g. foliage characteristics) for which readily measured indicators have been identified. The framework consists of five steps including compilation of an inventory of indicator; application of effectivity factors to rate indicators' effectiveness; estimation of effects; estimation of benefits for each ES; estimation of the total ES value of the ecosystem. The framework was applied to assess ecosystem services provided by trees, shrubs, herbs, birds, and bees, in green areas spanning an urban gradient in Gothenburg, Sweden. Estimates of perceived values of ecosystem services were obtained from interviews with the public and workshop activities with civil servants. The framework is systematic and transparent at all stages and appears to have potential utility in the existing spatial planning processes.
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| 4. |
- Grundström, Maria, 1979, et al.
(författare)
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Urban NO2 and NO pollution in relation to the North Atlantic Oscillation NAO
- 2011
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 45:4, s. 883-888
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Tidskriftsartikel (refereegranskat)abstract
- The North Atlantic Oscillation (NAO), a measure of the strength of the zonal wind across the North Atlantic Ocean, strongly influences weather conditions in NW Europe, e.g. temperature, precipitation and wind, especially during winter. It was hypothesised that elevated concentrations of nitrogen oxides in Gothenburg would be enhanced during negative NAO index (NAOI) conditions, representing more anticyclonic weather situations and thus leading to limited air mixing in the urban atmosphere, than situations with NAOI > 0. Hourly wintertime (DecembereFebruary) concentrations (1997e2006) of NO2, NO, air pressure, temperature and wind direction from an urban rooftop (30mabove street level) in the centre of the City of Gothenburg were analysed in relation to NAOI. Air pressure, the average concentration of nitrogen oxides (NOx ¼ NO2 þ NO), as well as the fraction of hourly NO2 and NO concentrations exceeding 90 mg m_3 and the fraction of daily NO concentrations exceeding 60 mg m_3, were significantly and negatively related to NAOI. Air temperature was positively correlated with NAOI. Southerly and westerly winds were more common in months with positive NAOI, while easterly and northerly winds were overrepresented in months with negative NAOI. High pollution concentrations dominantly occurred in situations with northerly and easterly wind directions. High NO2 and NO concentrations were associated with negative NAOI, especially in the morning when the traffic rush coincided with restricted air mixing. Over the tenyear period there were trends for more negative NAOI and increased time fractions with hourly NO2 concentrations exceeding 90 mgm_3. The conclusion of this study is that a climate shift towards higher or lower NAOI has the potential to significantly influence urban air pollution in North-West Europe, and thus the possibility to reach air quality standards, even if emissions remain constant.
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| 5. |
- Hageback, Johanna, et al.
(författare)
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Climate variability and land-use change in Danangou watershed, China
- 2005
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Ingår i: Climatic Change. - : Springer Science and Business Media LLC. - 1573-1480 .- 0165-0009. ; 72:1-2, s. 189-212
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Tidskriftsartikel (refereegranskat)abstract
- With global concern on climate change impacts, developing countries are given special attention due their susceptibility. In this paper, change and variability in climate, land use and farmers’ perception, adaptation and response to change are examined in Danangou watershed in the Chinese Loess Plateau. The first focus is to look at how climate data recorded at meteorological stations recently have evolved, and how farmers perceived these changes. Further, we want to see how the farmers respond and adapt to climate variability and what the resulting impact on land use is. Finally, other factors causing change in land use are considered. Local precipitation and temperature instrumental data and interview data from farmers were used. The instrumental data shows that the climate is getting warmer and drier, the latter despite large interannual variability. The trend is seen on the local and regional level. Farmers’ perception of climatic variability corresponds well with the data record. During the last 20 years, the farmers have become less dependent on agriculture by adopting a more diversified livelihood. This adaptation makes them less vulnerable to climate variability. It was found that government policies and reforms had a stronger influence on land use than climate variability. Small-scale farmers should therefore be considered as adaptive to changing situations, planned and non-consciously planned.
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| 6. |
- Hallgren, Jenny, 1978-, et al.
(författare)
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Implementing a person centred collaborative health care model : A qualitative study on patient experiences
- 2021
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Ingår i: International Emergency Nursing. - : Elsevier. - 1755-599X .- 1878-013X. ; 59
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Tidskriftsartikel (refereegranskat)abstract
- Background: Collaborative Health Care (CHC) is a unique model in which ambulance services, home health care, hospital care and the national telephone helpline for healthcare in Sweden – Swedish health care direct (SHD1177) collaborate to provide the fastest possible health care for inhabitants living in eleven municipalities in western region of Sweden. Aim: To explore how patients experience and perceive health care received in the CHC. Method: Qualitative descriptive study using open-ended individual telephone interviews with fifteen community dwelling persons with experiences of care throughthe model CHC were conducted. Results: Two main categories and six subcategories were identified. The category “Thoughts of time in regard to acute health care” include “CHC leads to shorter waiting time for health care”, “Knowledge about the staff working hours” and “To alert or not alert”. The category “Thoughts on unplanned health care from CHC” involved “Receiving health care in my home”, ”Coordination from SHD1177 surprises” and “Accessibility of health care values higher than continuity”. Conclusion: Integrated health care models such as CHC are time saving and highly appreciated by community dwelling persons. The benefits of provision of coherent health care like in CHC, addresses the need to implement innovative integrated healthcare models in today's health care.
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| 7. |
- Karlsson, Per Erik, et al.
(författare)
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Marknära ozon i södra Sverige. Utveckling av en manual för bedömning av överskridanden av målvärden.
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- På uppdrag av Länsstyrelserna i O, N, M, G, F, K samt H län har IVL Svenska Miljöinstitutet och Göteborgs Universitet genomfört en studie av förekomsten av marknära ozon i södra Sverige. Variationen i ozonförekomsten från kust och inåt landet har undersökts genom timvisa mätningar av ozonhalter och meteorologi med ett mobilt mätsystem i Skåne. Dessutom har kompletterande, månadsvisa mätningar bedrivits av medellufthalter av ozon och kvävedioxid samt temperatur. Vidare har de timvisa ozonmätningar som bedrivs vid Asa, SLU´s försökspark strax norr om Växjö, utvärderats med avseende på jämförelser med andra timvisa ozonmätningar som bedrivs i södra Sverige. Slutligen har praktiskt inriktad manual utarbetats för att möjliggöra länsvisa, yttäckande bedömningar av den årliga ozonförekomsten i relation till förekommande målvärden.
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| 8. |
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| 9. |
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| 10. |
- Karlsson, Per Erik, et al.
(författare)
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Past, present and future concentrations of ground-level ozone and potential impacts on ecosystems and human health in northern Europe
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 576, s. 22-35
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Tidskriftsartikel (refereegranskat)abstract
- This reviewsummarizes newinformation on the current status of ground-level ozone in Europe north of the Alps. There has been a re-distribution in the hourly ozone concentrations in northern Europe during 1990–2015. The highest concentrations during summer daytime hours have decreased while the summer night-time and winter day- and night-time concentrations have increased. The yearly maximum 8-h mean concentrations ([O3]8h,max), a metric used to assess ozone impacts on human health, have decreased significantly during 1990–2015 at four out of eight studied sites in Fennoscandia and northern UK. Also the annual number of days when the yearly [O3]8h,max exceeded the EU Environmental Quality Standard (EQS) target value of 60 ppb has decreased. In contrast, the number of days per year when the yearly [O3]8h,max exceeded 35 ppb has increased significantly at two sites, while it decreased at one far northern site. [O3]8h,max is predicted not to exceed 60 ppb in northern UK and Fennoscandia after 2020. However, theWHO EQS target value of 50 ppb will still be exceeded. The AOT40 May– July and AOT40 April–September metrics, used for the protection of vegetation, have decreased significantly at three and four sites, respectively. The EQS for the protection of forests, AOT40 April–September 5000 ppb h, is projected to no longer be exceeded for most of northern Europe sometime before the time period 2040–2059. However, if the EQS is based on Phytotoxic Ozone Dose (POD), POD1, it may still be exceeded by 2050. The increasing trend for low and medium range ozone concentrations in combination with a decrease in high concentrations indicate that a new control strategy, with a larger geographical scale than Europe and including methane, is needed for ozone abatement in northern Europe.
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| 11. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Comparison of modelled and measured ozone concentrations and meteorology for a site in south-west Sweden: Implications for ozone uptake calculations
- 2008
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 155:1, s. 99-111
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of ground-level ozone concentrations and meteorology (temperature, vapour pressure deficit (VPD), solar radiation) at the monitoring site Ostad (south-west Sweden) were compared to data from the corresponding grid in the EMEP photo-oxidant model for 1997, 1999 and 2000. The influence of synoptic weather on the agreement between model and measurements was studied. Implications of differences between modelled and observed inputs for ozone flux calculations for wheat and potato were investigated. The EMEP model output of ozone, temperature and VPD correlated well with measurements during daytime. Deviations were larger during the night, especially in calm conditions, attributed to local climatological conditions at the monitoring site deviating from average conditions of the grid. These differences did not lead to significant differences in calculated ozone uptake, which was reproduced remarkably well. The uptake calculations were sensitive to errors in the ozone and temperature input data, especially when including a flux threshold. (C) 2007 Elsevier Ltd. All rights reserved.
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| 12. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Declining ozone exposure of European vegetation under climate change and reduced precursor emissions
- 2014
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 11, s. 5269-5283
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Tidskriftsartikel (refereegranskat)abstract
- The impacts of changes in ozone precursor emissions as well as climate change on the future ozone exposure of the vegetation in Europe were investigated. The ozone exposure is expressed as AOT40 (Accumulated exposure Over a Threshold of 40 ppbO3) as well as PODY (Phytotoxic Ozone Dose above a threshold Y). A new method is suggested to express how the length of the period during the year when coniferous and evergreen trees are sensitive to ozone might be affected by climate change. Ozone precursor emission changes from the RCP4.5 scenario were combined with climate simulations based on the IPCC SRES A1B scenario and used as input to the Eulerian Chemistry Transport Model MATCH from which projections of ozone concentrations were derived. The ozone exposure of vegetation over Europe expressed as AOT40 was projected to be substantially reduced between the periods 1990–2009 and 2040–2059 to levels which are well below critical levels used for vegetation in the EU directive 2008/50/EC as well as for crops and forests used in the LRTAP convention, despite that the future climate resulted in prolonged yearly ozone sensitive periods. The reduction in AOT40 was mainly driven by the emission reductions, not changes in the climate. For the toxicologically more relevant POD1 index the projected reductions were smaller, but still significant. The values for POD1 for the time period 2040–2059 were not projected to decrease to levels which are below critical levels for forest trees, represented by Norway spruce. This study shows that substantial reductions of ozone precursor emissions have the potential to strongly reduce the future risk for ozone effects on the European vegetation, even if concurrent climate change promotes ozone formation.
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| 13. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Influence of urban vegetation on air pollution and noise exposure – A case study in Gothenburg, Sweden
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 599-600, s. 1728-1739
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution levels (NO2, PAHs, O3) were investigated, before (BLE) and after (ALE) leaf emergence, in the urban landscape of Gothenburg, Sweden. The aims were to study the 1) spatial and temporal variation in pollution levels between urban green areas, 2) effect of urban vegetation on air pollution levels at the same distance from a major emission source (traffic route), 3) improvement of urban air quality in urban parks compared to adjacent sites near traffic, 4) correlation between air pollution and noise in a park. O3 varied little over the urban landscape. NO2 varied strongly and was higher in situations strongly influenced by traffic. Four PAH variables were included: total PAH, total particle-bound PAH, the quantitatively important gaseous phenanthrene and the highly toxic particle-bound benzo(a)pyrene. The variation of PAHs was similar to NO2, but for certain PAHs the difference between highly and less polluted sites was larger than for NO2. At a vegetated site, NO2 and particulate PAH levels were lower than at a non-vegetated site at a certain distance from a busy traffic route. This effect was significantly larger ALE compared to BLE for NO2, indicating green leaf area to be highly significant factor for air quality improvement. For particulate PAHs, the effect was similar BLE and ALE, indicating that tree bark and branches also could be an important factor in reducing air pollution. Parks represented considerably cleaner local environments (park effect), which is likely to be a consequence of both a dilution (distance effect) and deposition. Noise and air pollution (NO2 and PAH) levels were strongly correlated. Comparison of noise levels BLE and ALE also showed that the presence of leaves significantly reduced noise levels. Our results are evidence that urban green spaces are beneficial for urban environmental quality, which is important to consider in urban planning.
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| 14. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Leaf area measurements of urban woodlands, parks and trees in Gothenburg, Sweden
- 2015
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Ingår i: ICUC9 – 9 th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. 20-24 July 2015, Toulouse, France.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Leaf area of urban vegetation is an important characteristic since it influences e.g. the urban climate through transpiratory cooling, air quality through air pollutant deposition and water management through rainfall interception. Measurements of leaf area are fundamental to accurately model these processes. Few studies have however presented leaf area measurements in the urban environment. The aim of this study was to i) describe the urban greenery based on measurements of leaf area index (LAI) of trees in different types of urban environments and ii) compare two different methods to measure LAI of urban trees. During the summer of 2014, LAI was measured in a central urban deciduous woodland, a suburban mixed forest, a central old park, a grove adjacent to a traffic route and in allotment gardens in Gothenburg, Sweden. In addition, single urban trees of seven common urban tree species in Gothenburg were measured (Acer platanoides, Aesculus hippocastanum, Betula pendula, Fagus sylvatica, Prunus serrulata, Quercus robur and Tilia europaea). Two different indirect methods were used; the LAI-2200 plant canopy analyzer (Li-cor Inc.) and hemispherical photography. The digital images were analyzed with Hemisfer (Schleppi, WSL). The canopy measurements were performed in a grid or cross with 8-32 points with fixed intervals. For single urban trees, 3-6 specimen of each species was measured. Average LAI of the measured urban parks and forests ranged between 2.6 and 4.8. A better way to characterize the different sites was to use cumulative density functions, which visualized the degree of heterogeneity. The old urban park had the largest LAI range (0 - 8.3). As a comparison, LAI ranged from 2.4 to 5.9 in the more homogenous urban woodland. LAI based on hemispherical photos was similar to the values received by the LAI-2200 plant canopy analyzer. Both methods had advantages and disadvantages. The urban environment offers challenges not present in forest canopies, such as interference of buildings. A combination of methods might be necessary for an environment as heterogeneous as the urban, with both single trees and forest canopies.
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| 15. |
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| 16. |
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| 17. |
- Klingberg, Jenny, 1978, et al.
(författare)
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NO, NO2 and O3 concentrations in the polluted urban landscape in comparison with a rooftop urban monitoring site and a rural site – influence of meteorology
- 2007
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Ingår i: Proceedings of the International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE), 24-28 June 2007, Skiathos, Greece. - 9789608981812 ; 4, s. 2423-2428
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Observed annual surface ozone maxima and minima in northern and central Europe from 1990–2015 — latitude dependence and temporal trends
- 2019
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Ingår i: Boreal environment research. - 1239-6095. ; 24, s. 201-214
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Tidskriftsartikel (refereegranskat)abstract
- Ground-level ozone is an air pollutant that, despite reductions in precursor emission in Europe, still represents a risk to vegetation and human health. This study is based on observations of ozone concentrations ([O3]) from 25 European monitoring stations, north of the Alps within the EMEP network, during the 26-year period from 1990–2015. We analyzed the maximum and minimum hourly [O3] as well as the seasonal cycle in relation to latitude. In addition, temporal trends were studied. The maximum [O3] increased towards the south of the study area, while the yearly minimum of daytime mean increased towards the north. There was a strong correlation between the day of year when the maximum [O3] occurred and latitude: the maximum [O3] occurred earlier in the north. The maximum daytime [O3] decreased at all stations while the minimum daytime [O3] increased at most stations during the studied time period.
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| 19. |
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| 20. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Ozone risk for vegetation in the future climate of Europe based on stomatal ozone uptake calculations
- 2011
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Ingår i: Tellus A. - : Stockholm University Press. ; 63, s. 174-187
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Tidskriftsartikel (refereegranskat)abstract
- The negative impacts of surface ozone (O3) on vegetation are determined by external exposure, leaf gas exchange and plant antioxidant defence capacity, all dependent on climate and CO2 concentrations. In this study the influence of climate change on simulated stomatal O3 uptake of a generic crop and a generic deciduous tree at ten European sites was investigated, using the LRTAP Mapping Manual stomatal flux model. O3 concentrations are calculated by a chemistry transport model (MATCH) for three 30-year time-windows (1961-1990, 2021-2050, 2071-2100), with constant precursor emissions and meteorology from a regional climate model (RCA3). Despite substantially increased modelled future O3 concentrations in central and southern Europe, the flux-based risk for O3 damage to vegetation is predicted to remain unchanged or decrease at most sites, mainly as a result of projected reductions in stomatal conductance under rising CO2 concentrations. Drier conditions in southern Europe are also important for this result. At northern latitudes, the current parameterisation of the stomatal conductance model suggest O3 uptake to be mainly limited by temperature. This study demonstrates the importance of accounting for the influences by climate and CO2 on stomatal O3 uptake, and of developing their representation in models, for risk assessment involving climate change.
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| 21. |
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| 22. |
- Klingberg, Jenny, 1978
(författare)
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The influence of climate on ozone risk for vegetation
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ground-level ozone (O3) is a harmful air pollutant causing reduced crop yield and quality, reduced forest growth and negative effects on human health in large parts of the world. O3 is generally seen as a regional scale air pollution problem, but O3 concentration ([O3]) variation on a smaller geographical scale can be considerable. Knowledge of the size of this local scale variation and the underlying causes is important in environmental monitoring and assessments of O3 exposure. The local scale variation in [O3] in Sweden was investigated and described in relation to local climate and site characteristics such as altitude, topography, vicinity to the coast and local NO emissions based on measurements of [O3] and meteorology with a mobile monitoring station. In addition, [O3] and [NO2] were measured with passive diffusion samplers and [O3] data from permanent monitoring stations were analysed. The strength of nocturnal temperature inversions was found to be crucial in determining the differences in average [O3] and diurnal [O3] range (DOR) at rural sites in southern Sweden. Inland low sites experienced stronger nocturnal temperature inversions, lower average [O3] and larger DOR compared to inland high and coastal sites. In addition, the underlying surface (important for the deposition rate), advection of O3-rich marine air and local NO emissions also influence the local scale variation of [O3]. The negative effects of O3 on vegetation are more closely related to the plant uptake of O3 through the stomata than to the [O3] in the ambient air. Environmental factors such as humidity, temperature and light, influence the degree of stomatal opening and thus the stomatal O3 flux into the leaf interior. The flux-based PODY-index (phytotoxic O3 dose above a flux threshold Y) was used to assess the O3 risk for vegetation. It allows modification of O3 uptake by climatic conditions to be incorporated in O3 risk assessment for vegetation. A large part of the local scale variation in [O3] in southern Sweden occurs during night-time. At night the stomatal O3 uptake by vegetation is low and the risk of O3 damage is therefore not greatly influenced. Thus, plant stomatal O3 uptake and O3 risk for vegetation are less influenced by the site position in the landscape than 24-hour average [O3]. At the coastal sites the [O3] were higher also during daytime, which implies an increased risk of negative effects of O3 on vegetation compared to inland sites. The influence of potential future climate change on the flux-based risk of negative effects of O3 on vegetation in Europe was investigated with modelled future [O3] from the chemistry transport model MATCH and meteorology from the regional climate model RCA3. The future plant O3 uptake and risk of O3 damage to vegetation was predicted to remain unchanged or decrease in Europe, despite substantially increased modelled [O3] in Central and Southern Europe. The expected reduction in stomatal conductance with rising atmospheric [CO2] is of large importance for this result. However, the magnitude of the CO2 effect is uncertain, especially for trees. If the CO2 effect will turn out to be small, future climate change has the potential to dramatically increase the flux-based O3 risk for vegetation in Northern and Central Europe.
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| 23. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Variation in ozone exposure in the landscape of southern Sweden with consideration of topography and coastal climate
- 2012
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 47, s. 252-260
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Tidskriftsartikel (refereegranskat)abstract
- Ozone concentrations ([O3]) and meteorological parameters were measured with a mobile monitoring station at two coastal and five inland sites in southwest Sweden. Three of the five inland sites were located topographically low and two high compared to the surrounding landscape. In addition, [O3] data from six permanent monitoring stations in southern Sweden were analysed in relation to the positions of the measurement sites in the landscape. [O3] was also measured with passive diffusion samplers at two other sites. Both the diurnal temperature range (DTR) and the diurnal [O3] range (DOR) were to a large extent explained by the strength of the nocturnal temperature inversions at the sites. To investigate the influence of topography, the relative altitude of the sites was defined as the average altitude within a 3 km radius subtracted from the altitude of the site. Statistically significant relationships were obtained for average [O3] as well as DOR with relative altitude. Inland low sites experienced stronger nocturnal temperature inversions, lower average [O3] and larger DOR compared to inland high and coastal sites. Relative altitude was found to be superior to site altitude in explaining the variation of average [O3] and DOR in the landscape. This study underlines the importance of including local topography, as well as vicinity to the coast, in modelling [O3] and in O3 environmental risk assessments.
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| 24. |
- Konarska, Janina, 1986, et al.
(författare)
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Applications of dual-wavelength hemispherical photography in urban climatology and urban forestry
- 2021
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Ingår i: Urban Forestry & Urban Greening. - : Elsevier BV. - 1618-8667 .- 1610-8167. ; 58
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Tidskriftsartikel (refereegranskat)abstract
- Digital hemispherical photography (DHP) is widely used to measure the radiative environment and estimate sky view factors (SVF) in urban areas and leaf area index (LAI) in forests. However, a limitation is the difficulty to distinguish trees from buildings, or leaves from stems and branches. In this study, we collected and processed dual-wavelength photographs recording visible and near-infrared (NIR) light in order to classify pixels into sky, green and woody plant elements, and buildings. Three applications of the method are presented: calculation of partial SVFs accounting for the obstruction of sky by buildings and vegetation separately, the modelling of mean radiant temperature (Tmrt), and the correction of LAI estimates for light intercepted by woody elements and buildings. The obtained partial SVFs were in good agreement with values modelled based on digital surface models. Distinguishing between buildings and vegetation in the modelling of long-wave radiation fluxes in the SOLWEIG model resulted in differences in modelled Tmrt by up to 3 °C. The bias of LAI estimates in urban parks caused by the light interception by woody elements and buildings was found to be relatively small (3–4 %). However, the presented method shows a high potential for estimates of LAI of urban vegetation in densely built-up areas.
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| 25. |
- Piikki, Kristin, et al.
(författare)
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Estimates of AOT ozone indices from time-integrated ozone data and hourly air temperature measurements in southwest Sweden
- 2009
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 157:11, s. 3051-3058
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Tidskriftsartikel (refereegranskat)abstract
- Surface ozone concentration and surface air temperature was measured hourly at three coastal sites, four low elevation inland sites and two high elevation inland sites in southwestern Sweden. Diurnal ozone concentration range (DOR) and diurnal temperature range (DTR) were strongly correlated, both spatially and temporally, most likely because both depended on atmospheric stability. Accumulated ozone exposure above a threshold concentration of x nmol mol(-1) (AOTx) was estimated from time-integrated ozone concentration (as from diffusive sampling) and measures of ozone concentration variability. Two methods both estimated 24-h AOTx with high accuracy (modelling efficiencies >90% for x <= 40 nmol mol(-1)). Daytime (08:00-20:00) AOTx could not be equally well estimated. Estimates were better for lower AOT thresholds. Diffusive ozone concentration sampling, combined with hourly temperature monitoring, could be a valuable complement to ozone concentration monitoring with continuous instruments. (C) 2009 Elsevier Ltd. All rights reserved.
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| 26. |
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| 27. |
- Piikki, Kristin, 1975, et al.
(författare)
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Mätningar av marknära ozon och meteorologi vid kustnära och urbana miljöer i Halland, Skåne och Västra Götalands län
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under sommaren 2007 mättes ozon- (O3) halter samt meteorologi kontinuerligt under ca en månads tid vardera, på en ö i havet (Nidingen, N län), vid en kustnära plats med förväntat höga ozonhalter (Backåkra, M län) samt i en urban parkmiljö (Göteborg, O län). På dessa platser samt på ytterligare fyra olika platser i Göteborg mättes även O3- och kväveoxid- (NOx = NO2 + NO) halter med diffusionsprovtagare på vecko-basis. Mätningarna vid Nidingen, Backåkra samt parkmiljön i Göteborg gjordes inte samtidigt utan under olika perioder under olika delar av sommarhalvåret. Jämförelser med andra kustnära platser (Råö, som ligger strax söder om Göteborg, och Malmö), där ozonhalten mättes under hela sommaren, visade att den kustnära ozondynamiken med hög medelhalt och liten dygnsvariation fanns vid båda mätplatserna, men var mer utpräglad på Nidingen än i Backåkra. Värdena för några olika ozonindex, bland annat 8-timmars-medelvärde, som används i miljömålet Frisk Luft samt inom Miljökvalitetsnormerna, var högre på Nidingen, trots att landets högsta ozonbelastning, enligt vissa modellberäkningar, kan förväntas i Skåne. En slutsats blir att små öar i havet kan vara mycket utsatta för ozon. Mätningarna i Göteborg visade att ozonförekomsten kan skilja sig väsentligt mellan olika urbana platser beroende på vindförhållanden och närhet till NOx-utsläpp, och att det bara är på platser med mycket hög trafiktäthet som titrering med NO har stor betydelse för den lokala ozonhalten. Ozonförekomsten i urban parkmiljö (Slottsskogen) kan vara relativt hög. Diffusionsprovtagarna fungerade bra för ozon och NO2.. I rapporten utvärderas olika enkla matematiska modeller för att uppskatta olika ozonindex utifrån mätningar med diffusionsprovtagare i kombination med temperaturmätningar eller genom att ta hänsyn till lokalens topografiska läge. Flera olika metoder fungerade väl och rekommendationer ges för hur de bör tillämpas i olika situationer.
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| 28. |
- Pleijel, Håkan, 1958, et al.
(författare)
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Accumulation of antimony and lead in leaves and needles of trees: The role of traffic emissions
- 2023
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Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Antimony (Sb) is a toxic metalloid, which has been increasingly used in the brake lining of vehicles, and increased concentrations have been found in soils near abundant traffic. However, since very few investigations of Sb accumulation in urban vegetation have been undertaken there exists a knowledge gap. We studied the concentrations of Sb in leaves and needles of trees in the Gothenburg City area, Sweden. In addition, lead (Pb), also associated with traffic, was investigated. Sb and Pb concentrations of Quercus palustris leaves at seven sites with contrasting traffic intensity varied substantially, correlated with the traffic-related PAH (polycyclic aromatic hydrocarbon) air pollution at the sites and increased during the growing season. Sb but not Pb concentrations were significantly higher in needles of Picea abies and Pinus sylvestris near major roads compared to sites at larger distances. In Pinus nigra needles at two urban streets both Sb and Pb were higher compared to an urban nature park environment, emphasising the role of traffic emissions for these elements. A continued accumulation of Sb and Pb in three years old needles of Pinus nigra, two years old needles of Pinus sylvestris and eleven years old needles of Picea abies was observed. Our data suggest a pronounced link between traffic pollution and Sb accumulation in leaves and needles, where the particles carrying Sb seem not to be transported very far from the source. We also conclude that there exists a strong potential for Sb and Pb bioaccumulation over time in leaves and needles. Implications of these findings are that increased concentrations of toxic Sb and Pb are likely to prevail in environments with high traffic intensity and that Sb can enter the ecological food chain by accumulation in leaves and needles, which is important for the biogeochemical cycling.
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| 29. |
- Pleijel, Håkan, 1958, et al.
(författare)
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Characteristics of NO2 Pollution in the City of Gothenburg, South-West Sweden—Relation to NO x and O3 Levels, Photochemistry and Monitoring Location
- 2009
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Ingår i: Water, Air, & Soil Pollution: Focus. - 1567-7230 .- 1573-2940. ; 9:1-2, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- Concentrations of NO2, NO, and O3 from a rooftop monitoring station in Gothenburg, Sweden (2002–2006) were analysed to characterise NO2 pollution. [NO2] was shown to correlate strongly and non-linearly with [NO x ] (NO x =NO+NO2), in line with observations in other cities. The [NO2] to [NO x ] fraction fell initially with increasing [NO x ]. At [NO x ] levels >200 ppb, the decline in [NO2]/[NO x ] with increasing [NO x ] levelled out and [NO2]/[NO x ] converged towards approximately 0.15–0.16, independent of [NO x ]. Data from a traffic route site showed the same pattern. This value of [NO2]/[NO x ] at high [NO x ] can be interpreted as the NO2 fraction of the NO x emissions from vehicle exhaust. Situations with high NO x pollution and minimum [NO2]/[NO x ] were always associated with [O3] close to zero. Plotting [Ox] (Ox=NO2+O3) vs. [NO x ] provided a strong linear correlation for situations dominated by local pollution ([NO]/[NO2]>1). The slope of the regression, a measure of the primary NO2 fraction in NO x emissions, was 0.13 during the day and 0.14 during the night. With stronger winds, the rooftop monitoring station became more similar, in terms of NO2 pollution, to a city street site and a traffic route site, although [NO2] was almost always higher at the street/traffic route locations. The EU standard for the annual average of [NO2] (40 μg m−3) was exceeded, while the hourly standard (200 μg m−3, not to be exceeded more than 18 times per year by 2010) was not exceeded at any of the sites.
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| 30. |
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| 31. |
- Pleijel, Håkan, 1958, et al.
(författare)
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Differences in accumulation of polycyclic aromatic compounds (PACs) among eleven broadleaved and conifer tree species
- 2022
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Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 145
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Tidskriftsartikel (refereegranskat)abstract
- PACs (polycylic aromatic compounds) are air pollutants formed in incomplete combustion, e.g., in vehicle engines. Vegetation can potentially remove substantial amounts and act as bioindicators of these pollutants. Increased knowledge of the pollutant removal efficiencies of different tree species is essential for understanding the potential benefits trees can provide urban residents. We investigated the leaf/needle content of the two PAC groups, polycyclic aromatic hydrocarbons (PAHs, 32 compounds) and dibenzothiophenes (DBTs, 6 compounds) in seven broadleaved and four conifer tree species in an arboretum of South-West Sweden. PAHs were grouped into low-molecular (L-PAHs, largely gaseous), medium-molecular (M-PAHs, both gaseous and particle-bound) and high-molecular mass (H-PAHs, largely particle-bound) PAHs. DBTs are organosulphur compounds with two benzene rings. In general, conifer needles were stronger accumulators of PACs than leaves of broadleaved trees. Comparing three-year-old and one-year-old needles showed that evergreen conifers accumulated L-PAHs, M-PAHs, H-PAHs and DBTs over several years. In deciduous trees, L-PAHs and DBTs declined from June to September, M-PAHs had no significant net change, but for H-PAHs, there was a significant net accumulation. Conifers had a similar or lower net average annual accumulation of H-PAHs than broadleaved trees, except the deciduous conifer Larix, which had the highest uptake rate of this toxicologically important PAH category. Our results suggest that L-PAH accumulation depends on leaf/needle mass or volume, while for H-PAHs leaf/needle area is more important. This explains why conifers represented a stronger sink for L-PAHs and M-PAHs. DBT accumulation in leaves/needles was similar to that of L-PAHs. An important conclusion is that tree leaves/needles accumulate substantial amounts of PAC with strong and complex contrasts between tree species and PAC groups. Another implication of our data is that conifer needles are useful as bioindicators for PAC pollution since they accumulate all PAC categories over several years.
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| 32. |
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| 33. |
- Pleijel, Håkan, 1958, et al.
(författare)
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Mercury accumulation in leaves of different plant types – the significance of tissue age and specific leaf area
- 2021
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 18, s. 6313-6328
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Tidskriftsartikel (refereegranskat)abstract
- Mercury, Hg, is one of the most problematic metals from an environmental perspective. To assess the problems caused by Hg in the environment, it is crucial to understand the processes of Hg biogeochemistry, but the exchange of Hg between the atmosphere and vegetation is not sufficiently well characterized.We explored the mercury concentration, [Hg], in foliage from a diverse set of plant types, locations and sampling periods to study whether there is a continuous accumulation of Hg in leaves and needles over time. Measurements of [Hg] were made for deciduous and conifer trees in Gothenburg, Sweden (botanical garden and city area), as well as for evergreen trees in Rwanda. In addition, data for wheat from an ozone experiment conducted at Östad, Sweden, were included. Conifer data were quantitatively compared with literature data. In every case where older foliage was directly compared with younger, [Hg] was higher in older tissue. Covering the range from the current year up to 4-year-old needles in the literature data, there was no sign of Hg saturation in conifer needles with age. Thus, over timescales of approximately 1 month to several years, the Hg uptake in foliage from the atmosphere always dominated over Hg evasion. Rwandan broadleaved trees had generally older leaves due to lack of seasonal abscission and higher [Hg] than Swedish broadleaved trees. The significance of atmospheric Hg uptake in plants was shown in a wheat experiment where charcoal-filtrated air led to significantly lower leaf [Hg]. To search for general patterns, the accumulation rates of Hg in the diverse set of tree species in the Gothenburg area were related to the specific leaf area (SLA). Leaf-area-based [Hg] was negatively and non-linearly correlated with SLA, while mass-based [Hg] had a somewhat weaker positive relationship with SLA. An elaborated understanding of the relationship behind [Hg] and SLA may have the potential to support large-scale modelling of Hg uptake by vegetation and Hg circulation.
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| 34. |
- Pleijel, Håkan, 1958, et al.
(författare)
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Surface Ozone in the Marine Environment—Horizontal Ozone Concentration Gradients in Coastal Areas
- 2013
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 224:7
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Tidskriftsartikel (refereegranskat)abstract
- Spring/summer surface ozone concentrations, [O3], in coastal environments were investigated: (1) by comparison of coastal and inland monitoring stations with data from a small island >5 km off the coast of southwest Sweden, (2) as a gradient from the coast towards inland in southernmost Sweden. Further, results from the chemical transport model MATCH were used to assess the marine influence on [O3]. It was hypothesised that [O3] is higher on the small island compared to the coast, especially during night and in offshore wind. Another hypothesis was that [O3] declines from the coast towards inland. Our hypotheses were based on observations that the deposition velocity of O3 to sea surfaces is lower than to terrestrial surfaces, and that vertical air mixing is stronger in the marine environment, especially during night. The island experienced 10 % higher [O3] compared to the coast. This difference was larger with offshore (15 %) than onshore wind (9 %). The concentration difference between island and coast was larger during night, but prevailed during day and could not be explained by differences in [NO2] between the sites. The difference in [O3] between the island and the inland site was 20 %. Higher [O3] over the sea, especially during night, was reproduced by MATCH. In the gradient study, [O3] declined from the coast towards inland. Both [O3] and [NO2] were elevated at the coast, indicating that the gradient in [O3] from the coast was not caused by NO titration. The conclusions were that surface [O3] in marine environments is higher than in coastal, and higher in coastal than inland areas, especially during night.
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