Urban Temperatures

microclimate

small scale variations in temperature/precipitation/humidity/wind speed/evaporation that occurs in an environment

albedo

reflectivity of a surface

ratio between amount of incoming insolation and amount of energy reflected back

what has a greater albedo

light surfaces

urban heat island effect

temperature of a city is higher than surrounding areas

causes of UHI

low albedo, lack of green spaces, anthropogenic heat, air pollutants

causes: low albedo

concrete/apshalt/brick store heat during day and release at night

dark surfaces on roads and buildings

causes: lack of green spaces

reduces evapotranspiration and its cooling effect

causes: anthropogenic heat

cars, industrial processes, energy consumption from buildings

causes: air pollutants

trap outgoing radiation, creating pollution dome

UHI effects

heatwaves, heatstrokes

increased energy use from air conditioning

UHI management

green roofs and walls absorb heat

urban greening provides shade and transpiration

improved urban design, wider streets