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- LCZ4r package R for local climate zones and urban heat islandsPublication . Anjos, Max; Medeiros, Dayvid; Castelhano, Francisco; Meier, Fred; Silva, Tiago; Correia, Ezequiel; Lopes, AntónioThe LCZ4r is a novel toolkit designed to streamline Local Climate Zones (LCZ) classification and Urban Heat Island (UHI) analysis. Built on the open-source R statistical programming platform, the LCZ4r package aims to improve the usability of the LCZ framework for climate and environment researchers. The suite of LCZ4r functions is categorized into general and local functions (https://bymaxanjos.githu b.io/LCZ4r/index.html). General functions enable users to quickly extract LCZ maps for any landmass of the world at different scales, without requiring extensive GIS expertise. They also generate a series of urban canopy parameter maps, such as impervious fractions, albedo, and sky view factor, and calculate LCZ-related area fractions. Local functions require measurement data to perform advanced geostatistical analysis, including time series, thermal anomalies, air temperature interpolation, and UHI intensity. By integrating LCZ data with interpolation techniques, LCZ4r enhances air temperature modeling, capturing well-defined thermal patterns, such as vegetation-dominated areas, that traditional methods often overlook. The openly available and reproducible R-based scripts ensure consistent results and broad applicability, making LCZ4r a valuable tool for researchers studying the relationship between land use-cover and urban climates.
- Heat stress mitigation by exploring UTCI hotspots and enhancing thermal comfort through street treesPublication . Silva, Tiago; Matias, Márcia; Girotti, Carolina; Vasconcelos, João; Lopes, AntónioHeat stress mitigation actions must be carefully planned in order to achieve efective outcomes. By integrating urban planning guidelines with urban climate knowledge, substantial benefts can be achieved for the community. In Lisbon, the study area, urban planning guidelines are strict in relation to the tree species which should be used for planting. This study examined these species environmental contributions to the community, especially in regard to heat stress mitigation in two urban canyons previously found as UTCI hotspots. For this, microclimatic Envi-met simulations were run which allowed recalculation of the UTCI hotspot analysis and to assess individual species contribution to possible mitigation eforts. Results demonstrated the ability of these trees to lower air temperature and the Universal Thermal Climate Index (UTCI). By reducing UTCI temperatures between 3.19 °C and 6.27 °C on a hot summer’s day, these trees were also able to transform an identifed UTCI hotspot into a coldspot. From the studied species, Pyrus calleryana was found to be the most efective species for mitigating thermal stress, although all three species performed well. Regarding community services, according to the iTree tool, Cercis siliquastrum had the greatest overall impact. These results give to the municipal urban planning which tree species should be prioritized in terms of climate action, as well as a methodological framework to assess at local scale which areas should be intervened.
- Thermal preference and pleasantness of a students’ population in a coastal urban area during summerPublication . Silva, Tiago; Lopes, António; Vasconcelos, João; Morgado, PauloIn thermal comfort research, two main domains are identified: objective and subjective. This study focusses on the latter, examining various aspects of preference, sensation, and pleasantness. It also clearly distinguishes each concept and sets the groundwork for their standardised use in urban planning and urban climate studies. Additionally, this study emphasises the often-overlooked geographical perspective, aiming to address previous gaps in this research area. Environmental conditions were found to be the main determinants influencing pedestrians' thermal sensation, preference, and pleasure. Key factors include air temperature, solar radiation, and wind speed, which exhibit strong correlations with pleasure responses. Additionally, urban density, clothing type and colour, shading, sex, and weather type significantly impact thermal sensation and reported pleasantness. It was observed that people who overdressed for the season, wore dark or warmer clothes, experienced air temperature and solar radiation more intensely. Similarly, those in high-density urban areas, without shade, or when weak continental wind conditions were observed, reported stronger thermal sensations. Women generally sensed air temperature and solar radiation as more intense compared to men. These factors influence thermal pleasantness, varying in importance, spatial distribution, and statistical relationship. Higher wind speeds, particularly from an Atlantic direction, were found to enhance thermal pleasantness by balancing conditions and reducing thermal sensation votes for air temperature and solar radiation. Green areas also increased thermal pleasantness by lowering air temperature and solar radiation sensations and promoting a sense of happiness among pedestrians.
- A micro-scale look into pedestrian thermophysiological comfort in an urban environmentPublication . Silva, Tiago; Lopes, António; Vasconcelos, JoãoDiferent spatial scales enable the analysis of thermophysiological conditions of pedestrians in an urban environment. A higher resolution hotspot analysis was conceived using GIS technology in some areas of Lisbon with diferent morphological conditions. Eleven hotspots were found across six study areas, located in high to moderate urban density conditions and in diferent types of urban spaces. So, six hotspots were found in avenues (high urban density conditions), three in streets, and two in general open spaces (moderate urban density conditions). These spaces are characterized by being busy areas with high anthropogenic infuence, with high-absorbing and refective materials, and with very poor green infrastructure. Environmental conditions, namely, radiation, mean radiant temperature, and air temperature, were the main cause of hotspot existence, and the main propellers for UTCI intensifcation. The urban density variable was also found to be important, especially in avenues and open spaces. In these areas, the adjusted component for environmental and urban density conditions can increase 0.60 to 1.35 °C in open spaces and 0.30 to 0.60 °C in avenues, each time there is a one-unit increase in the component. Trees, either in the street or in parks, have generally been found to decrease the UTCI.
- Air pollution Dynamics: the role of meteorological factors in PM10 concentration patterns across urban areasPublication . Girotti, Carolina; Fernando Kowalski, Luiz; Silva, Tiago; Correia, Ezequiel; Shimomura, Alessandra R. Prata; Akira Kurokawa, Fernando; Lopes, AntónioAir pollution is a major health problem in urban areas, influenced by traffic and atmospheric conditions. This study investigates the relationship between meteorological factors—wind direction, wind speed, boundary layer height, and atmospheric stability conditions —street trees, and PM10 concentration in three urban canyons: Avenida da Liberdade and Estrada de Benfica in Lisbon, and Marginal Tietˆe in S˜ ao Paulo. Five years of hourly meteorological data and PM10 concentrations were analysed. Despite differences in scale and traffic volume, the results show that PM10 concentration patterns were similar in both Lisbon study areas. These areas also indi cated a significant influence of atmospheric variables such as wind speed, boundary layer height, and atmo spheric stability conditions. Tietˆe, with a higher vehicle density and different atmospheric conditions (lower wind speeds and greater atmospheric stability), presents higher PM10 peaks. Seasonal analysis revealed distinct patterns influenced by atmospheric instability, wind speed, and direction. In winter, areas with dense street tree cover had reduced PM10 levels, while those without showed higher concentrations due to increased stability. Wind direction played a crucial role, favouring the pollutant dispersal in canyons with parallel winds. The Factorial Analysis of Mixed Data method identified qualitative variables linked to the seasons, wind direction, and presence of trees. PM10 levels below the were associated with the summer and autumn period, parallel winds, and street trees, while levels above the limit were linked to winter period and areas without street trees. By integrating big data analytics with environmental monitoring, this research underscores the importance of considering the local atmospheric conditions and environmental variables in the urban air quality management. Thus, it demonstrates that the traffic volume alone does not determine PM10 concentrations; instead, the interplay of multiple factors, including meteorological conditions and urban planning, played a crucial role. This study provides valuable insights for developing effective strategies to mitigate urban air pollution and protect public health.
- Climate walking: A comparison study of mobile weather stations and their relevance for urban planning, design, human health and well-beingPublication . Silva, Tiago; Ramusga, R.; Matias, Márcia; Amaro, J.; Bonifácio, Ana; Reis, Cláudia; Chokhachian, A.; Lopes, G.; Almeida, A.; Frazão, J.; Vasconcelos, J.; Lopes, António; Morgado, PauloMicroclimate conditions affect the outdoor urban way of life for humans. These conditions directly impact people’s health and well-being, such as access to medical care or a healthy lifestyle. Human thermal comfort is paramount for people’s health, both physical and mental. In this paper, the study compares two microclimate mobile weather stations (MWS) based on a set of users’-based assessment criteria (usability, user-friendliness, sensors) and thermal comfort (UTCI) results accuracy. The comparison was carried out through continuous mobile transect measurements lasting an hour and a half, conducted on two summer days in Lisbon across distinct urban morphological settings. This research was developed to assist future researchers in urban climatology with the design of microscale studies, particularly in relation to equipment selection, performance assessment, and methodological procedures. In terms of performance, we found the RMSE to be 1.3 ◦C for air temperature, 1.6 % for relative humidity, 1.3 m/s for wind speed, and 8.4 W/m2 for solar radiation for MWS 1, and 1.5 ◦C for air temperature, 2.9 % for relative humidity, 1.5 m/s for wind speed, and 11.6 W/m2 for radiation for MWS 2. Both MWS units exhibited a consistent performance, however, MWS 1 demonstrated greater overall accuracy, particularly in the measurement of air temperature, relative humidity, and wind speed. Differences were also observed between the sensors of MWS 1 and MWS 2, as well as in the MWS usability, factors which may be significant depending on the users’ objectives and available resources. Despite this, both MWS units were deemed suitable for deployment in urban environments, with MWS 2 offering a more intuitive user experience. The findings of this study are particularly relevant for those beginning mobile meteorological measurements, as well as for researchers aiming to address urban heat stress and enhance public well-being and thermal comfort through their work. However, the study is limited by its short duration and geographic scope, and further research is needed to expand its applicability to diverse urban settings.
- Thermal stress and comfort assessment in urban areas using Copernicus Climate Change Service Era 5 reanalysis and collected microclimatic dataPublication . Silva, Tiago; Lopes, António; Vasconcelos, João; Chokhachian, Ata; Wagenfeld, Malte; Santucci, DanieleIn this initial study of a research project, this paper seeks to understand the thermal conditions in the cities of Lisbon and Munich, specifcally focusing on Urban Heat Island intensity and on thermal comfort using the Universal Thermal Climate Index modeling data at the Local Climate Zone scale. Based on these datasets, Munich has exhibited more unfavourable thermal conditions than Lisbon. In terms of UHII, both cities have shown that low, medium, and high rise compact urban areas and bare rock or paved areas have the highest values, while sparsely built areas have the lowest. These results difer from the UTCI, which indicates that in Lisbon and Munich, these sparsely built areas as well as areas with low plants and vegetation are the most uncomfortable. In Munich, the population was exposed to very strong heat stress, while Lisbon experienced strong heat stress conditions. Conversely, low, medium, and high rise compact urban areas and densely wooded areas in Munich, and scattered trees areas and large low-rise urban areas in Lisbon, have demonstrated the lowest monthly mean and average maximum values. These results will be further explored in future studies in the city of Lisbon and crosschecked with data obtained from roving missions. This will enable a more detailed temporal and local analysis.
- A micro-scale look into pedestrian thermophysiological comfort in an urban environmentPublication . Silva, Tiago; Lopes, António; Vasconcelos, JoãoDifferent spatial scales enable the analysis of thermophysiological conditions of pedestrians in an urban environment. A higher resolution hotspot analysis was conceived using GIS technology in some areas of Lisbon with different morphological conditions. Eleven hotspots were found across six study areas, located in high to moderate urban density conditions and in different types of urban spaces. So, six hotspots were found in avenues (high urban density conditions), three in streets, and two in general open spaces (moderate urban density conditions). These spaces are characterized by being busy areas with high anthropogenic influence, with high-absorbing and reflective materials, and with very poor green infrastructure. Environmental conditions, namely, radiation, mean radiant temperature, and air temperature, were the main cause of hotspot existence, and the main propellers for UTCI intensification. The urban density variable was also found to be important, especially in avenues and open spaces. In these areas, the adjusted component for environmental and urban density conditions can increase 0.60 to 1.35 °C in open spaces and 0.30 to 0.60 °C in avenues, each time there is a one-unit increase in the component. Trees, either in the street or in parks, have generally been found to decrease the UTCI.
- Climate walking and linear mixed model statistics for the seasonal outdoor thermophysiological comfort assessment in LisbonPublication . Silva, Tiago; Reis, Cláudia; Braz, Diogo; Vasconcelos, João; Lopes, AntónioTo measure urban outdoor pedestrian thermophysiological comfort mobile roving missions were conducted in all seasons of the year during the day and at night. Six routes were chosen, representing areas of the city with varying urban morphological layouts. The thermal comfort conditions were analysed using the Local Climate Zone spatial scale. This enabled the identification of typologies of areas where pedestrians might feel (un)comfortable. To achieve the proposed objectives, quantitative and qualitative analysis were run, namely a Linear Mixed-Effect Model. This model was useful to understand the thermal behaviour of the roved areas by comparison to a reference area. The city was found to be generally cooler, except at night when it can have a 44% increased UTCI. Most collected values throughout the year had ‘no thermal stress’, except in the summer when ‘moderate’ and ‘strong heat stress’ was predominant. Compact and large low rise urban areas were found to be the most uncomfortable. Significant amplitudes were found in some LCZs, reaching as high as 7 ◦C in some scenarios. Sparsely wooded areas exhibited higher values in all seasons and at night, except in the summer. This showed that for a local heat stress analysis a higher resolution scale is needed.
- Air pollution dynamics: the role of meteorological factors in PM10 concentration patterns across urban areasPublication . Girotti, Carolina; Kowalski, Luiz; Silva, Tiago; Correia, Ezequiel; R. Prata Shimomura, Alessandra; Akira Kurokawa, Fernando; Lopes, AntónioAir pollution is a major health problem in urban areas, influenced by traffic and atmospheric conditions. This study investigates the relationship between meteorological factors—wind direction, wind speed, boundary layer height, and atmospheric stability conditions —street trees, and PM10 concentration in three urban canyons: Avenida da Liberdade and Estrada de Benfica in Lisbon, and Marginal Tietê in São Paulo. Five years of hourly meteorological data and PM10 concentrations were analysed. Despite differences in scale and traffic volume, the results show that PM10 concentration patterns were similar in both Lisbon study areas. These areas also indicated a significant influence of atmospheric variables such as wind speed, boundary layer height, and atmospheric stability conditions. Tietê, with a higher vehicle density and different atmospheric conditions (lower wind speeds and greater atmospheric stability), presents higher PM10 peaks. Seasonal analysis revealed distinct patterns influenced by atmospheric instability, wind speed, and direction. In winter, areas with dense street tree cover had reduced PM10 levels, while those without showed higher concentrations due to increased stability. Wind direction played a crucial role, favouring the pollutant dispersal in canyons with parallel winds. The Factorial Analysis of Mixed Data method identified qualitative variables linked to the seasons, wind direction, and presence of trees. PM10 levels below the were associated with the summer and autumn period, parallel winds, and street trees, while levels above the limit were linked to winter period and areas without street trees. By integrating big data analytics with environmental monitoring, this research underscores the importance of considering the local atmospheric conditions and environmental variables in the urban air quality management. Thus, it demonstrates that the traffic volume alone does not determine PM10 concentrations; instead, the interplay of multiple factors, including meteorological conditions and urban planning, played a crucial role. This study provides valuable insights for developing effective strategies to mitigate urban air pollution and protect public health.