Sofia Thorsson

Thermal Comfort and Outdoor Activity in Japanese Urban Public Places

Subjective thermal comfort and outdoor activity in a park and a square in a satellite city northeast of Tokyo were investigated through structured interviews, observations, and comprehensive micrometeorological measurements. Results showed that the park was on an average 1.1°C cooler than the square. The relatively warmer thermal conditions in the square in comparison to the park resulted in a heat load of greater intensity for humans in the square. In general, there was a low relation between the thermal environment and the use of the two places in terms of total attendance. However, the use of the park was influenced more by the thermal conditions than by the use of the square, which can mainly be attributed to the different functions of the two places. Finally, examples of the differences between the use of the sun, the attitudes toward it, and outdoor exposure in Japan and Sweden are highlighted and discussed.

Psychological mechanisms in outdoor place and weather assessment: towards a conceptual model.

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.

COOLING RATES, SKY VIEW FACTORS AND THE DEVELOPMENT OF INTRA‐URBAN AIR TEMPERATURE DIFFERENCES

Abstract Intra‐urban cooling rates were monitored for a year in the centre of Göteborg on the Swedish west coast. Five sites with different building geometry ‐ from dense canyon to open space ‐ within a radius of 300 m were analysed. Results showed two modes of cooling during the night. In the first mode, the cooling was site‐dependent ‐the open space cooled the most and the dense canyon the least. In the second mode, which began about 3–4 hours after sunset, all sites cooled at the same rate. Our hypothesis is that in the early part of the evening both radiative divergence and sensible heat dominate the cooling. However, as the evening progresses, a spatially homogeneous inversion is established which controls the radiative cooling, making the cooling independent of both surface geometry and surface type. From April to November the sites cooled rapidly around sunset and the cooling slowly decreased during the rest of the night. However, between December and March, the cooling was less intense, with an almost constant rate during the entire night. It has been suggested that this might be the result of the draining of stored solar heat during the summer and a continuous flux of anthropogenic heating during the winter.

Characteristics of the mean radiant temperature in high latitude cities—implications for sensitive climate planning applications

Knowledge of how the mean radiant temperature (Tmrt) is affected by factors such as location, climate and urban setting contributes to the practice of climate sensitive planning. This paper examines how Tmrt varies within an urban setting and how it is influenced by cloudiness. In addition, variations of Tmrt in three high latitude cities are investigated in order to analyse the impact of geographical context and climate conditions. Results showed large spatial variations between sunlit and shaded areas during clear weather conditions, with the highest values of Tmrt close to sunlit walls and the lowest values in the areas shaded by buildings and vegetation. As cloudiness increases, the spatial pattern is altered and the differences are reduced. The highest Tmrt under cloudy conditions is instead found in open areas where the proportion of shortwave diffuse radiation from the sky vault is high. A regional comparison between three Swedish coastal cities showed that Tmrt during summer is similar regardless of latitudinal location. On the other hand, large differences in Tmrt during winter were found. Shadows, both from buildings and vegetation are the most effective measure to reduce extreme values of Tmrt. However, extensive areas of shadow are usually not desired within outdoor urban environments at high latitude cities. One solution is to create diverse outdoor urban spaces in terms of shadow and also ventilation. This would provide individuals with access to a choice of thermal environments which they can use to assist their thermal regulation, based on personal needs and desires.

Effect of urban design on microclimate and thermal comfort outdoors in warm-humid Dar es Salaam, Tanzania

Due to the complexity of built environment, urban design patterns considerably affect the microclimate and outdoor thermal comfort in a given urban morphology. Variables such as building heights and orientations, spaces between buildings, plot coverage alter solar access, wind speed and direction at street level. To improve microclimate and comfort conditions urban design elements including vegetation and shading devices can be used. In warm-humid Dar es Salaam, the climate consideration in urban design has received little attention although the urban planning authorities try to develop the quality of planning and design. The main aim of this study is to investigate the relationship between urban design, urban microclimate, and outdoor comfort in four built-up areas with different morphologies including low-, medium-, and high-rise buildings. The study mainly concentrates on the warm season but a comparison with the thermal comfort conditions in the cool season is made for one of the areas. Air temperature, wind speed, mean radiant temperature (MRT), and the physiologically equivalent temperature (PET) are simulated using ENVI-met to highlight the strengths and weaknesses of the existing urban design. An analysis of the distribution of MRT in the areas showed that the area with low-rise buildings had the highest frequency of high MRTs and the lowest frequency of low MRTs. The study illustrates that areas with low-rise buildings lead to more stressful urban spaces than areas with high-rise buildings. It is also shown that the use of dense trees helps to enhance the thermal comfort conditions, i.e., reduce heat stress. However, vegetation might negatively affect the wind ventilation. Nevertheless, a sensitivity analysis shows that the provision of shade is a more efficient way to reduce PET than increases in wind speed, given the prevailing sun and wind conditions in Dar es Salaam. To mitigate heat stress in Dar es Salaam, a set of recommendations and guidelines on how to develop the existing situation from microclimate and thermal comfort perspectives is outlined. Such recommendations will help architects and urban designers to increase the quality of the outdoor environment and demonstrate the need to create better urban spaces in harmony with microclimate and thermal comfort.

Can participants predict where ambulance-requiring cases occur at a half marathon?

Despite endurance races leading to a substantial number of ambulance‐requiring cases (ARC), little is known regarding where they occur, meaning that knowing where to place medical teams, ambulance pick‐up points, etc, is difficult. This article investigates whether the location of ARCs can be identified by race participants.

PA 13-2-0532 Testing a novel method for identifying where serious medical encounters occur at marathons in order to improve medical preparedness and runners’ safety

During the last decade, an increasing global popularity of endurance events has been seen, with a particular increase in the number of both half and full city marathons. Although events that promote physical activity are important, particularly from a public health perspective, endurance events also lead to a considerable number of medical emergencies. Despite this, very little is known regarding where serious life-threatening medical encounters (SLTMEs) occur during a race. Also, it is not known if the locations coincide with where runners experience the race as the most exhausting. Using the world’s largest half marathon (Gothenburg half marathon) as a case, SLTME data collected from the local ambulance provider (over 7 years), and data from runners’ experiences (n=237) is presented. Level of agreement tests are performed and, using the runners’ experiences as a template, specific high-risk clusters are presented. SLTMEs are shown to be considerably more common towards the end of the race and in uphill sections. By asking runners where they found the race most exhausting, it is possible to identify places where the risk of SLTMEs will be greater and thereby where medical personnel should be stationed. From a practical perspective, using this method could considerably increase the safety of competitors as well as improving the cost-effectiveness of safety interventions at endurance races.