| 1. |
- Eliasson, Ingegärd, 1961, et al.
(author)
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Climate and behaviour in a Nordic city
- 2007
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In: LANDSCAPE AND URBAN PLANNING. - : Elsevier BV. - 0169-2046 .- 1872-6062. ; 82:1-2, s. 72-84
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Journal article (peer-reviewed)abstract
- Four urban public spaces, representing various designs and microclimates, were investigated in Gothenburg, Sweden, in order to estimate how weather and microclimate affect people in urban outdoor environments. The research strategy was both multidisciplinary and interdisciplinary and included scientists from three disciplines: architecture, climatology and psychology. The project is based on common case studies carried out during four seasons, including measurements of meteorological variables, interviews and observations of human activity at each place. Multiple regression analysis of meteorological and behavioural data showed that air temperature, wind speed and clearness index (cloud cover) have a significant influence on people's assessments of the weather, place perceptions and place-related attendance. The results support the arguments in favour of employing climate sensitive planning in future urban design and planning projects, as the physical component of a place can be designed to influence the site-specific microclimate and consequently people's place-related attendance, perceptions and emotions.
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| 2. |
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| 3. |
- Knez, Igor, 1959-, et al.
(author)
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Psychological mechanisms in outdoor place and weather assessment: towards a conceptual model
- 2009
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In: International Journal of Biometeorology. - : Springer Science and Business Media LLC. - 1432-1254 .- 0020-7128. ; 53:1, s. 101-111
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Journal article (peer-reviewed)abstract
- The general aim has been to illuminate the psychological mechanisms involved in outdoor place and weather assessment. This reasoning was conceptualized in a model, tentatively proposing direct and indirect links of influence in an outdoor place–human relationship. The model was subsequently tested by an empirical study, performed in a Nordic city, on the impact of weather and personal factors on participants’ perceptual and emotional estimations of outdoor urban places. In line with our predictions, we report significant influences of weather parameters (air temperature, wind, and cloudlessness) and personal factors (environmental attitude and age) on participants’ perceptual and emotional estimations of outdoor urban places. All this is a modest, yet significant, step towards an understanding of the psychology of outdoor place and weather assessment.
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| 4. |
- Lindberg, Fredrik, 1974
(author)
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Modelling the urban climate using a local governmental database
- 2007
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In: Meteorological Applications. ; 14:3, s. 263-273
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Journal article (peer-reviewed)abstract
- In this study, local government digital spatial data are used to describe urban geometry and analyse spatial variations of the urban climate within the central areas of Göteborg, Sweden. A high-resolution raster digital elevation model (1 m pixel resolution) consisting of building structures and ground heights is derived from a local government geo-database, as well as land use patterns and artificial heat sources. Parameters such as the sky view factor (SVF) and daily averages of solar radiation are calculated. Results obtained from the model are compared with intra-urban air temperature variations which are derived from mobile measurements, as well as surface temperature variations derived from thermal infrared images. Results show that high-resolution digital elevation models in raster format are very useful sources of data for the investigation of intra-urban temperature variations. Results also show that the areal mean of SVF correlates with intra-urban air temperature variations to a higher degree than SVF that is taken from a point source location. The correlation between the modelled SVF and surface temperature is high during both spring and winter. Adding information about daily averages of global radiation for the spring measurement causes the correlation between SVF and surface temperature variations to increase. Copyright © 2007 Royal Meteorological Society
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| 5. |
- Lindberg, Fredrik, 1974
(author)
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Modelling the urban microclimate using local governmental 3-d raw data
- 2006
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In: Lindqvist, S, Grimmond, CBS, (eds.), The sixth International Conference on Urban Climate. ; , s. 867-870
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Conference paper (peer-reviewed)abstract
- The access and quality of digital spatial data covering urban areas have increased substantially in recent decades. As a result new methods using different kinds of spatial data within the field of urban climatology has been developed. This paper illustrates how digital data could be used to analyze spatial variations of the urban climate using a detailed Digital Elevation Model (DEM). Parameters such as the Sky View Factor (SVF) and insolation properties are modeled using municipality data covering the central areas of the city of Göteborg in Sweden. Model validation is conducted using hemispheric photographs and meteorological measurements.
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| 6. |
- Lindberg, Fredrik, 1974, et al.
(author)
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SOLWEIG 1.0 – Modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings
- 2008
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In: International Journal of Biometeorology. ; 52, s. 697-713
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Journal article (peer-reviewed)abstract
- The mean radiant temperature, Tmrt, which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and Tmrt in complex urban settings, is presented. The Tmrt is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries – a large square and a small courtyard in Göteborg, Sweden (57°N) – across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of Tmrt, with an overall good correspondence of R 2=0.94, (p<0.01, RMSE=4.8 K). SOLWEIG 1.0 is still under development. Future work will incorporate a vegetation scheme, as well as an improvement of the estimation of fluxes from the four cardinal points.
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| 7. |
- Lindberg, Fredrik, 1974, et al.
(author)
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SOLWEIG - The new model for calculating the mean radiant temperature
- 2009
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In: The Seventh International Conference on Urban Climate.
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Conference paper (other academic/artistic)abstract
- The new radiation model, SOLWEIG (SOlar and LongWave Environmental Irradiance Geometry-model), which simulates three-dimensional daytime short-wave and long-wave radiation fluxes as well as mean radiant temperature (Tmrt) in complex urban settings is presented in this paper. It is a grid based, non-stationary model that is able to compute spatial variations of radiation fluxes and Tmrt on very large model domains and on various temporal scales. The first version of the SOLWEIG model (1.0) uses built structures for representing urban geometry. In the second version (2.0) a vegetation scheme that is able to account for the radiative properties of trees and bushes which affects the outcome of the radiation fluxes and hence Tmrt will be included. Work on setting up a user-friendly interface for model runs is also demonstrated.
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| 8. |
- Lindberg, Fredrik, 1974
(author)
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Spatial variations of the urban climate and its influence on thermal comfort and behaviour
- 2007
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Doctoral thesis (other academic/artistic)abstract
- The increased number of people living in urban areas emphasises the need for an improved understanding of how the urban climate affects human activity and behaviour. The spatial and temporal variation of climate within cities is an important factor in people’s health and well-being. The purpose of the work presented in this thesis is to contribute to a better understanding of the spatial variations of climate and bioclimate in urban areas and to investigate people’s usage and perception of the urban outdoor environment based on microclimatological and meteorological conditions. The thesis also includes work on the improvement of measurement techniques and modelling of the mean radiant temperature, one of the most important meteorological parameters governing human energy balance. An array of different meteorological, behavioural and geoprocessing methods were used in this thesis. Spatial variations of air temperature were examined by mobile measurements in both Göteborg, Sweden (57°N) and Szeged, Hungary (46°N). Surface temperature variations in Göteborg were examined by airborne infrared thermal mapping. The geoprocessing work included in this thesis was mainly based on raster modelling using high resolution Digital Elevation Models (DEM) of building structures and ground topography. In order to study how human behaviour is related to weather and climate, extensive field campaigns of simultaneous micrometeorological and behavioural measurements were carried out in three cities: Göteborg and Luleå in Sweden (65°N) and Tokyo in Japan (36°N). Studies were conducted across seasons and in different urban places such as squares, parks and waterfront plazas. Urban geometry is commonly represented by the Sky View Factor (SVF) in urban climate studies. The results presented in this thesis show that only a weak relationship exists between SVF at a point source and the average mean of SVFs taken around the same point source. This implies that SVF derived from a single location cannot be used to represent a larger source area of averaged SVFs. Two different methods for deriving continuous images of SVFs (raster and vector-based methods) give very similar values of SVF. However, the raster-based technique is considerably faster than the vector-based method. Areal average SVFs have a much better degree of correlation with intra-urban air temperature variations than SVF values that are taken at a single location. Consequently, areal averages of SVF values should be used in future intra-urban air temperature studies. Regarding climate and human behaviour, the results confirm that air temperature is the major determinant for the use of urban outdoor places, i.e., the higher the air temperature, the greater usage. The thesis also outlines examples of how good design strategies may increase and prolong the usage of these spaces and outdoor activity throughout the year. Furthermore, it is shown that weather parameters (cloudiness, air temperature and wind speed) have a significant influence on participants’ weather assessments and place-related perceptions, emotions and attendance. It is thus clear that cloudiness, air temperature and wind are vital aspects of the functional and psychological components of a place. A globe thermometer is used to derive the mean radiant temperature (Tmrt). The results show good agreement between the values of Tmrt obtained by a 38 mm flat grey globe thermometer and those obtained by integral radiation measurement. The new formula presented in this thesis provides a simple, mobile and cheap method and thus a valuable tool for thermal comfort researchers, urban planners and designers. Concerning the modelling of Tmrt, a new model SOLWEIG, which calculates spatial variations of Tmrt based on simple meteorological data and urban geometry is presented in this thesis. There is good agreement between the values obtained from the model and measured values of Tmrt.
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| 9. |
- Lindberg, Fredrik, 1974-
(author)
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Studies of Oxygen Deficient Complex Cobaltates with Perovskite Related Structures
- 2006
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Doctoral thesis (other academic/artistic)abstract
- The present thesis deals with the investigation of some perovskite related complex cobaltates. The phases Sr2Co2-xGaxO5 (0.3 ≤ x ≤ 0.7), Sr2Co2-xAlxO5 (0.3 ≤ x ≤ 0.5), Sr1-xBixCoO3-y (0.1 ≤ x ≤ 0.2), Sr0.75Y0.25Co1-xGaxO2.625 (0.125 ≤ x ≤ 0.375) and Sr0.75Y0.25Co1-xFexO2.625+δ (0.125 ≤ x ≤ 0.625) were synthesised and characterised. All these compounds crystallises with similar structures, they are all composed by altering layers of octahedra and tetrahedra although in the two former, the tetrahedra are organised in chains (the Brownmillerite structure), while in the latter three the tetrahedra arranges as segregated Co4O12 units (the 314 type structure). The techniques X-ray and neutron diffraction, transmission electron microscopy, thermal analysis and magnetic measurements were used to track structural and important physical properties.
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| 10. |
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