The complex interplay between climate change, demographics and socioeconomic conditions is transforming the global environmental health landscape. In the aftermath of recent heat waves around the world, especially the 2003 heat wave in Europe, heat is being recognized as an emerging public health issue worldwide, particularly in urban areas. This work explores the historical and future heat-related mortality in New York City, from the beginning of the 20th until the end of the 21st century. New York City is among the largest cities in the world and has been a thriving metropolis over the entire period covered by this study. The unique makeup of the city makes it particularly suitable for studying the impacts of heat over an extended period of time. The presented work encompasses multiple domains of knowledge and illustrates the necessity for applying highly interdisciplinary approaches in addressing the emerging challenges of our time. The background chapter provides an overview of methodological approaches and findings from previous studies with direct relevance to the specific aims of this work. Chapter I is focused on characterizing the impacts of heat on daily mortality since 1900. Here, heat effects are presented in a historical context and changes over time are analyzed and discussed. Chapter II provides a comparative assessment of recent historical and heat impacts until 2100 in New York City, Boston and Philadelphia. This analysis illustrates the differences and similarities between heat impacts in New York City and the other two major urban areas in the U.S. Northeast. Chapter III provides a more comprehensive assessment of future heat-related mortality in New York City under a number of adaptation, climate change and demographic scenarios. The concluding chapter presents a summary of findings and recommendations for future research.

The complex interplay between climate change, demographics and socioeconomic conditions is transforming the global environmental health landscape. In the aftermath of recent heat waves around the world, especially the 2003 heat wave in Europe, heat is being recognized as an emerging public health issue worldwide, particularly in urban areas. This work explores the historical and future heat-related mortality in New York City, from the beginning of the 20th until the end of the 21st century. New York City is among the largest cities in the world and has been a thriving metropolis over the entire period covered by this study. The unique makeup of the city makes it particularly suitable for studying the impacts of heat over an extended period of time. The presented work encompasses multiple domains of knowledge and illustrates the necessity for applying highly interdisciplinary approaches in addressing the emerging challenges of our time. The background chapter provides an overview of methodological approaches and findings from previous studies with direct relevance to the specific aims of this work. Chapter I is focused on characterizing the impacts of heat on daily mortality since 1900. Here, heat effects are presented in a historical context and changes over time are analyzed and discussed. Chapter II provides a comparative assessment of recent historical and heat impacts until 2100 in New York City, Boston and Philadelphia. This analysis illustrates the differences and similarities between heat impacts in New York City and the other two major urban areas in the U.S. Northeast. Chapter III provides a more comprehensive assessment of future heat-related mortality in New York City under a number of adaptation, climate change and demographic scenarios. The concluding chapter presents a summary of findings and recommendations for future research.

Os efeitos causados pela presença de áreas urbanizadas da Região Metropolitana de São Paulo (RMSP), conhecidos por ilha de calor urbana, são estudados através da modelagem numérica e da análise de alguns dados observacionais, coletados no período de inverno de 1999 durante a 1ª Fase intensiva de medidas de campo do Projeto Temático FAPESP “Meteorologia e Poluição do Ar em São Paulo" e da rede automática da CETESB. Através da utilização de imagens do satélite LANDSAT-5, foi obtido um arquivo de ocupação do solo na RMSP numa resolução de aproximadamente 424 m. Foram definidos dois tipos de ocupação urbana que diferem principalmente na verticalização e espaçamento entre as construções. Simulações realizadas com uma parametrização adequada ao tratamento das propriedades da superfície em áreas urbanas, o modelo RAMS-TEB, mostraram que as fontes antropogênicas de calor de origem veicular são de grande importância no ciclo diurno de temperatura e umidade na RMSP. Uma comparação entre os dados simulados pelo modelo e dados observacionais de superfície apresentou coeficientes de correlações superiores a 0,9 para a temperatura e superiores a 0,8 para a umidade relativa. A interação entre a brisa marítima e a ilha de calor intensifica as zonas de convergência no centro da cidade, podendo ocasionar a re-circulação de poluentes nessa região. Simulações sobre o efeito da urbanização mostram que a ilha de calor urbana faz com que haja uma propagação mais rápida da frente de brisa até o centro da RMSP, que permanece estacionária por algum tempo nessa região. Os efeitos da topografia mostraram-se fundamentais na intensidade da brisa marítima e sua propagação sobre o continente. A presença de grandes corpos d’água, tais como a represa de Guarapiranga e Billings, contribui para a diminuição das amplitudes do ciclo diurno de temperatura na RMSP através das circulações do tipo brisa lacustre geradas pelos mesmos. O uso de um modelo de dispersão mostrou que, com a propagação da frente de brisa para o interior (na direção SE-NW), poluentes emitidos na RMSP são transportados para áreas remotas, diminuindo a concentração dos mesmos nas regiões emissoras. / The effects caused by urbanization in the Metropolitan Area of São Paulo (MASP), known as urban heat island, are studied through the use of numerical modeling and some observed data, collected in the 1999’s winter time during the first phase of intensive field measurements from the Thematic Project FAPESP “Meteorology and Air Pollution in São Paulo" and also from CETESB automatic network. A 424 m resolution land use file was created using LANDSAT-5 satellite pictures where two different kinds of urban regions were identified. The main differences between these regions are the vertical structure and spacing between buildings. Simulations performed with an appropriate parameterization for the treatment of surface properties in urban areas showed that anthropogenic sources due to traffic are of great importance to the temperature and humidity diurnal cycle in MASP. Comparisons between simulated and observed surface data had a correlation coefficient greater than 0.9 for temperature and greater than 0.8 for relative humidity. The interaction between the see breeze and the urban heat island intensify the convergence zones in the center of the city, eventually causing the re-circulation of pollutants in this region. Simulations of the urbanization effects showed that the urban heat island is responsible for a faster propagation of the sea breeze front up to the center of the MASP, remaining stationary in this region for some time. The topographic effects are fundamental in the intensity of the sea breeze and its inland propagation. The presence of large water bodies, as the Guarapiranga and Billings Dams, contribute to a decrease in the temperature diurnal cycle amplitudes because of the lake breeze circulations generated by them. The use of a simple dispersion model showed that with the propagation of the sea breeze front to the countryside (in the direction SE-NW), pollutants emitted in MASP are transported to remote areas, causing a decrease in the concentration of these pollutants in the source region.

The urban near surface atmosphere is of great concern since it affects the climate to which an increasing amount of people are immediately exposed. This study investigated the microclimate in central Stockholm in terms of the thermal conditions in the 0-2.5 m air layer and the water and heat exchange processes at different types of surfaces found within the urban environment. The main objective was to improve our understanding of the urban small-scale climate system. The urban microclimate was measured in terms of vertical air temperature profiles along a horizontal transect running through a vegetated park and its built-up surroundings during three clear and relatively calm summer days. The results showed that the air temperature at 1.2 m height within the park was 0.5 to 1.5 K lower than in the surrounding city blocks, and that the thermal stratification was generally stable (increasing temperature with height) in the park and unstable (decreasing temperature with height) in the built-up areas. In addition, there were a few examples of temperature gradients orientated in different directions within the lowest 2.5 m air layer, indicating horizontal advection between the park and the built-up areas. Climate conditions simulated with a three-dimensional microclimate model agreed well with observations and the model was therefore assumed to provide reasonable representations of important climate processes such as surface-air energy exchange processes. However, there were some discrepancies between observations and simulations that are discussed in terms of differences in real and modelled heat storage processes and wind conditions. Processes that need to be included for a more precise model description of areas such as the Stockholm environment include dynamic heat storage in buildings and dynamic wind forcing during the course of the simulation. A soil-vegetation-atmosphere transfer model was used to study soil water transport, the surface energy balance of an asphalt surface, and the impact of urban climate on evapotranspiration. Based on model calibration to field measurements of soil water content in a till catchment outside Stockholm, new parameter values were estimated that can be used for water flow modelling of till soils. The heat fluxes of an asphalt surface were reliably simulated without knowledge of site-specific calibration and the model was useful in identifying problems with energy balance closure based on measurements only. Simulations of ‘urban’ modifications to the forcing climate conditions demonstrated that increased air temperature, and thereby increased vapour pressure deficit, had most effect on evapotranspiration from tall vegetation, while increased long-wave radiation raised grass evapotranspiration the most. / QC 20100901

This study analyzes the trends in temperature, and their extremes, in the Greater Toronto Area (GTA) in the context of urban heat island. The trends in annual and seasonal temperature changes were investigated in the GTA over the past century and a half with special focus on 1970-2000. The Mann-Kendall test is used to assess the significance of the trends and the Theil-Sen slope estimator is used to identify their magnitude. Statistically significant increasing trends for mean and minimum temperatures are observed mainly at the urban and suburban stations. The sequential Mann-Kendall test is used to identify any abrupt change in the time series of temperature (31 -161 years), and the results indicate that increasing trend for annual mean temperature has started after 1920 at Toronto downtown, after the 1960s at the suburban stations, and has increased significantly during the 1980s at all stations, which is consistent with the pace of urbanization during these periods in the GTA. The observed urban heat island (UHI) in Toronto is quantified and characterized by considering three different rural stations. The UHI intensity (∆Tu-r) in Toronto is categorized as winter dominating or summer dominating depending on the choice of a rural station. The results from the trend analysis of annual and seasonal ∆Tu-r suggest that the choice of the rural station is crucial in the estimation of ∆Tu-r, and thus can overestimate or underestimate its prediction depending on the location and topographical characteristics of a rural station relative to the urban station. The trends in extreme temperature indices are also investigated and the results indicate that indices based on daily maximum temperature are more pronounced at the urban and suburban stations compared to that at the rural stations. The changes in the trends for extreme indices based on daily minimum temperature are consistent at all stations for the period of 1971-2000. With the decrease in the percentage of cold nights and the increase in the percentage of warm nights, the diurnal temperature range has decreased throughout the GTA region. The analysis of heating degree days and cooling degree days revealed that the former is associated with decreasing trends and the latter exhibited increasing trends at almost all stations in the GTA. Finally, it is evident from the results that urban heat island phenomenon exerts warmer influence on the climate in cities, and with the current pace of urbanization in the GTA, it is imperative to understand the potential impact of the emerging UHI on humans and society.

This study analyzes the trends in temperature, and their extremes, in the Greater Toronto Area (GTA) in the context of urban heat island. The trends in annual and seasonal temperature changes were investigated in the GTA over the past century and a half with special focus on 1970-2000. The Mann-Kendall test is used to assess the significance of the trends and the Theil-Sen slope estimator is used to identify their magnitude. Statistically significant increasing trends for mean and minimum temperatures are observed mainly at the urban and suburban stations. The sequential Mann-Kendall test is used to identify any abrupt change in the time series of temperature (31 -161 years), and the results indicate that increasing trend for annual mean temperature has started after 1920 at Toronto downtown, after the 1960s at the suburban stations, and has increased significantly during the 1980s at all stations, which is consistent with the pace of urbanization during these periods in the GTA. The observed urban heat island (UHI) in Toronto is quantified and characterized by considering three different rural stations. The UHI intensity (∆Tu-r) in Toronto is categorized as winter dominating or summer dominating depending on the choice of a rural station. The results from the trend analysis of annual and seasonal ∆Tu-r suggest that the choice of the rural station is crucial in the estimation of ∆Tu-r, and thus can overestimate or underestimate its prediction depending on the location and topographical characteristics of a rural station relative to the urban station. The trends in extreme temperature indices are also investigated and the results indicate that indices based on daily maximum temperature are more pronounced at the urban and suburban stations compared to that at the rural stations. The changes in the trends for extreme indices based on daily minimum temperature are consistent at all stations for the period of 1971-2000. With the decrease in the percentage of cold nights and the increase in the percentage of warm nights, the diurnal temperature range has decreased throughout the GTA region. The analysis of heating degree days and cooling degree days revealed that the former is associated with decreasing trends and the latter exhibited increasing trends at almost all stations in the GTA. Finally, it is evident from the results that urban heat island phenomenon exerts warmer influence on the climate in cities, and with the current pace of urbanization in the GTA, it is imperative to understand the potential impact of the emerging UHI on humans and society.

published_or_final_version / Architecture / Master / Master of Philosophy

published_or_final_version / Geography / Master / Master of Philosophy

No description available.

This thesis aims to examine the spatial relationship between elevated air temperatures and populations most vulnerable to heat across the urban environment. To assess this correlation, the analysis focuses on the cities of Atlanta, Georgia and Minneapolis, Minnesota. A three-part methodology was employed: first, continuous air temperature was estimated using satellite imagery and weather station observations; second, a heat vulnerability index was generated based on demographic, social, and environmental variables at the Census block group level; and third, a spatial statistical analysis was performed to measure the correlation between the hottest temperatures and the populations most vulnerable to heat. Finally, the thesis concludes with policy recommendations that address the comprehensive nature of vulnerability in relation to extreme heat. As municipalities and local governments plan for a future with warmer temperatures and larger urban populations, effective policies must be designed with respect to both the social and physical environments; the results herein can help inform such strategies.