URBAN MICROCLIMATES

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URBAN MICROCLIMATES
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Construction of cities lead to Profound changes
in the climate of a specific locality
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What do cities do?

• They destroy the existing microclimate and create
  new ones.
• There are three processes involved
• 1. production of heat
• 2. alteration of land surface
• 3. modification of the atmosphere

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PRODUCTION OF HEAT

• Combustion of fuels
• Release of heat stored in citys brickwork and
  concrete
• Creation of urban heat island

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Altlanta urban heat island
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Urban heat profile
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Another urban heat profile!
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Urban temperature transect
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ALTERATION OF LAND SURFACE

• Buildings and streets can change wind speeds

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Other urban variables to consider
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Wind velocities can vary very locally in urban
areas
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Wind velocities can be increased!
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MODIFICATION OF THE ATMOSPHERE

• Air pollution reduces sunlight
• Development of smog
• Calm conditions with descending air and warm
  pollutants rising create an inversion layer.

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Los Angeles inversion layer
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• Increase in condensation nuclei leading to fog