Micro Climates Flashcards
What is albedo
The relectivity of a surface. The ratio between the amount of incoming insolation and the amount of energy reflected back to the atmosphere
What is a microclimate?
The small scale variations in temperature, precipitation, humidity, wind speed and evaporation that occurs in particular environment such as an urban area
What is a urban dome?
The urban micro climate is sometimes called this
The area where the weather is different from that of surrounding rural areas
What are the two levels in the Urban dome?
Urban canopy
Urbn boundary
What is photochemical pollution?
A form of air pollution that mainly occurs in cities. It can be dangerous to health.
What causes photochemical pollution
Exhaust fumes are trapped by temperature inversion and in the presence of sunlight, low level ozone forms.
What is photochemical pollution associated with?
High pressure weather systems
Anti cyclonic conditions
What is a temperature inversion?
An atmospherice condition which temperature unusually increases with height. Inversions are really stable and do not allow convection, they trap pollution in the lower part of the atmosphere
What is the urban heat island?
The zone around and above an urban area which has higher temperatures than the surrounding areas
What is isotherm?
A line joining places with equal temperatures
What is channelling (weather) or urban canyons
Wind redirected down long, staright canyon like streetswhere there is less friction.
An example of urban canyon
New York, straight streets and located next to open water where there is strong winds
What is the venturi effect?
The squeezing of wind into an increasingly narrow gap, resulting in pressure decrease amd velocity increas of winds
What happens to the amount of sunshine hours in urban micro climates?
Lower
What happens to the average mean temperature of an urban microclimate?
Its higher than its surroundings
