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Leva McIntire Daniel Martell Marcus Tubbs. Urban Thermal Heat Islands. Thermal Heat Island Causes and Consequences. The situation. (Photos courtesy Photos.com and the Landsat program). Thermal Heat Islands (THIs) are the thermal effects observed around urban areas around the globe..
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Leva McIntire Daniel Martell Marcus Tubbs Urban Thermal Heat Islands
Thermal Heat Island Causes and Consequences The situation
(Photos courtesy Photos.com and the Landsat program) Thermal Heat Islands (THIs) are the thermal effects observed around urban areas around the globe.. These THIs pose a general health threat to urban populations specifically morbidity and mortality. THIs have been suspected to cause severe weather down the wind stream of larger cities. It is our task to develop an ESS analysis about the effects of thermal heat islands on the urban and suburban settings. Our goal is to identify what makes a thermal heat island as intense as it is and suggest mitigation policies. First discovered by Luke Howard when collecting data for his book, Weather of London 1818-1820, when he noticed that average temperature was significantly higher than the rural surrounding areas, particularly at night. The Thermal Heat Island Effect: What is it?
Large Concrete Areas Deforestation of urban areas. High Population Density High levels of pollutants Causes
Are Thermal islands seasonal? • Even if a thermal island is the cause of an EHE (excessive heat event), the causes of the thermal island don't go away in the other seasons. • Most of the health complications are caused by EHEs, however, which are defined as summertime weather that is substantially hotter and/or more humid than average for a location at that time of year. • So thermal islands are not seasonal, but most of their adverse effects are.
Increased Levels of Morbidity and Mortality • Affects specific groups • Amplification of heat waves • Heat inversion traps pollutants • Pollutants cause additional health related problems (smog). • Pollutants create a green house effect (positive feedback). The Negative Impact
Power Demand • Cities have a large demand for power. • Increased power demand during heat waves leads to an increased output of waste heat. • Inefficiency = wasted energy = more heat output • This acts as a positive feedback mechanism increasing the overall impact of thermal islands. Negative Impact Continued
Mitigation Suggestions • Increased vegetation in urban areas. • Green roofs. • Increased water area. 1) Map of Manhattan showing the vegetation density within the city. Image courtesy of NASA. http://earthobservatory.nasa.gov/Features/GreenRoof/
http://earthobservatory.nasa.gov/Features/GreenRoof/ Sources