Leva McIntireDaniel MartellMarcus Tubbs

Thermal Heat Island Causes and Consequences

•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.

(Photos courtesy Photos.com and the Landsat program)

Large Concrete Areas Deforestation of urban areas. High Population Density High levels of pollutants

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).

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.

The next step in urban progress and development

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/